Hey folks...
Okay. Get this. I had opened up my NES and cleaned the inside with half/half (isopropyl/water) fluid on lint free cloths and had dried it also. The cartridge slot, I mean. I had done this periodically and had put it off long enough that finally I went and did it again after over a year.
Things were fine that night after I put it back together. Perfect as expected, in fact.
The *next* day (on a clean game, mind you).... sound was silent. At first I merely checked the TV volume and the connection to the TV but both were fine. ALL games were silent, although nothing else was wrong with their behavior.
The Zelda cartridge thing sounded very much like my thing except this is with ALL games, on clean cartridges. I intend to check tomorrow (though I think I *did* re-clean later) to see if anything crept onto the connector (especially when I removed it)... it's unlikely given that it was fine the day before after being put back together, but I'm finding it unlikely that I only shorted one tiny thing on the NES board somehow without shorting more than just that, so the "one pin being affected" thing feels like something to check.
Is there anything anyone here might be able to tell me that can help what I'm trying to do? I ran a cloth over the mobo esp. over the sound area just in case. I'm not someone who would do soldering because I'd ruin stuff... no training or equipment, though I know someone who can solder if I *MUST*. On the plus side, nothing else is going wrong with it... on the minus side, that hasn't brought the sound back.
In the interests of full disclosure it should be noted that I was using a Honeybee converter for the first time after cleaning it and the two Famicom cartridges I used with it, but that too was operating correctly and with sound the previous day to my recollection. I can detail more about my usage of the converter if that's relevant.
I took some digital photographs of the inside of the NES but I don't know if any of them are close-view enough (or unobstructed enough by the flash) to be of use (I took the photos to compare with online photos of where the sound was so I could find the proper location to try cleaning it).
Ideas are welcome. Help me? :P
Hi,
Are you sure the cables you are using aren't defective?
Can you do what blackevilweredragon did (check output pin on CPU)?
I've been really busy and was only able to finally get to trying things out with my NES today. Hopefully somebody will still see this thread after this :).
Anyway, I did try cleaning things up and inspecting the edge connectors again and checking cable connections and so on, but the net result didn't restore sound. I had noticed that the NTSC sticker was possibly covering part of the edge connector of the mobo, so I removed it, but it probably had been there to begin with. As for the output pin on the CPU (wasn't it the cartridge for him) I uh... couldn't find anything wrong that I didn't run cleaning cloth over. The system is still superbly responsive, but silent. I would *like* to see if sound comes off the connectors, but as I said before, I have no soldering experience. Can I have connections RESTING on those two sound tips to test if sound is coming out of them without actually "soldering" them on? Is physical contact enough to do a test? And if so, what kind of connectors do I use and what do I hook up to it? I'd like to see if sound is coming out, since I'm not sure what else to do now unless anyone else has suggestions. Again, I do have photos as mentioned previously, though nothing looks different than a normal NES board.
I realize there may be nothing I can do. But if anyone has ideas or thinks I *can* do something, their help would be appreciated.
The CPU is in the console.. The ant in my cartridge was causing a short that was somehow disabling the CPU's sound circuit..
Attack a speaker to the pins on the CPU (one of the sound output pins...).. If you can hear sound, then the short is somewhere elsewhere..
Cleaning cloth, on the circuit board? Nooooooooooooo.... You should always clean with AIR.. What kind of cleaning cloth? It probably had static buildup, and fried the CPUs sound circuit...
Post the photos, maybe we can see what's the problem...
QuoteCan I have connections RESTING on those two sound tips to test if sound is coming out of them without actually "soldering" them on? Is physical contact enough to do a test?
You can remove the audio cable and touch the central pin (of the cable) to where the audio should be (Cpu IC pins or other parts of the PC), but be VERY careful to not cause a short circuit.
http://www.raphnet.net/electronique/nes_mo...d_en.php#stereo (http://www.raphnet.net/electronique/nes_mod/nes_mod_en.php#stereo)
I know the CPU is on the console... I mean, trying to identify which "black box" it is :). Actually, rereading your ant story puzzles me... the ant was on the cartridge, right? Yet sound still came out of the sound tips and only shorted further down the line inside the system? On the other hand, if the ant was in the system, wouldn't there have been no sound even in other games?
Don't worry... this is just ordinary lint-free cloth like CD wipes. While something along the connection may have been shorted, the NES sound is generated by the CPU and I doubt I shorted the CPU, since again, the system runs perfectly. - Anyway, it's been all over the system, and the system is fine. And yes, I did originally clean with air... back when the sound died in the first place. :P
Which cable is the audio cable I should be removing? I actually did see the place where you linked, which let me know where the sound was being sent out, but that cable in those photos is one affixed by the guy doing that mod, not a cable that was already there. The other "cables" on the system either don't budge (and I'm wondering if they are removable so I didn't force them) or are the blue cable connector on that one side of the motherboard, which seems to be the power and anyway seems to be fine. Do I touch the two little things there (as in the left photo) with shielded cable... and if so, where do I plug the other end of the shielded cable into? Can that go directly into speakers, or...?
As for the photos... I'll try to post links to them later when I find a place to upload them to. Looking at them though, I don't really see any physically remiss characteristics, and I wonder if some shots are too far away from relevant things to help. Anyway, I'll try to do that in a bit but for now any of the above can be replied to? :) I can take more specific photos if necessary also.
QuoteI know the CPU is on the console... I mean, trying to identify which "black box" it is :). Actually, rereading your ant story puzzles me... the ant was on the cartridge, right? Yet sound still came out of the sound tips and only shorted further down the line inside the system? On the other hand, if the ant was in the system, wouldn't there have been no sound even in other games?
Don't worry... this is just ordinary lint-free cloth like CD wipes. While something along the connection may have been shorted, the NES sound is generated by the CPU and I doubt I shorted the CPU, since again, the system runs perfectly. - Anyway, it's been all over the system, and the system is fine. And yes, I did originally clean with air... back when the sound died in the first place. :P
Which cable is the audio cable I should be removing? I actually did see the place where you linked, which let me know where the sound was being sent out, but that cable in those photos is one affixed by the guy doing that mod, not a cable that was already there. The other "cables" on the system either don't budge (and I'm wondering if they are removable so I didn't force them) or are the blue cable connector on that one side of the motherboard, which seems to be the power and anyway seems to be fine. Do I touch the two little things there (as in the left photo) with shielded cable... and if so, where do I plug the other end of the shielded cable into? Can that go directly into speakers, or...?
As for the photos... I'll try to post links to them later when I find a place to upload them to. Looking at them though, I don't really see any physically remiss characteristics, and I wonder if some shots are too far away from relevant things to help. Anyway, I'll try to do that in a bit but for now any of the above can be replied to? :) I can take more specific photos if necessary also.
The ant was in the game cartridge...
The CPU has two parts to it, the core, and the sound.. The sound can get fried, while the core still runs.. You haven't seen the weirdest things I have seen.. I've seen a PC boot up with a bad CPU!! (only to crash when you load a game that used SSE)..
How are you connecting the NES to your TV? Through the RF connection on the back, or the video/audio connection on the side? You take the Audio cable on the side of the NES (that goes to your TV), and touch it's pin to the sound pin on the CPU... (make sure the video cable is connected, you need it's ground!)
this side..
(http://www.nintendo.com/consumer/systems/nes/images/av_vcr.gif)
Is that really possible? To just touch the RCA sound jack's metal part onto the CPU? I thought the signal underwent some changing before it was really in the format for an RCA cable audio signal (In fact, I thought the power box also dealt with translating the signals).
Anyway, yes, I use RCA connections. The video and audio quality improvement is not to be missed ;). Actually, someone suggested trying to RF switch plug/coaxial connection to see if that worked, but I doubt it would since I think that gets downconverted from the RCA signal after a copy of that signal is first sent to the RCA jacks. I'll admit I haven't done that check yet, but I've rarely gotten the time to deal with the NES... this "sound died" thing happened nearly a month ago now even though I've only had the time to try fixing it two or three times so far.
So which thing exactly would I touch the sound RCA jack to? The "sound" thing in the photographs seems to have metal ends on two sides, and be two things to boot. Also, can someone else confirm if this works before I actually try touching it to it? I'd really rather not make things worse if that can happen :P. As for the CPU, that brings me back to "which black thing on the mobo is it."
Above guest is me. Forgot to type in the name.
QuoteIs that really possible? To just touch the RCA sound jack's metal part onto the CPU? I thought the signal underwent some changing before it was really in the format for an RCA cable audio signal (In fact, I thought the power box also dealt with translating the signals).
Anyway, yes, I use RCA connections. The video and audio quality improvement is not to be missed ;). Actually, someone suggested trying to RF switch plug/coaxial connection to see if that worked, but I doubt it would since I think that gets downconverted from the RCA signal after a copy of that signal is first sent to the RCA jacks. I'll admit I haven't done that check yet, but I've rarely gotten the time to deal with the NES... this "sound died" thing happened nearly a month ago now even though I've only had the time to try fixing it two or three times so far.
So which thing exactly would I touch the sound RCA jack to? The "sound" thing in the photographs seems to have metal ends on two sides, and be two things to boot. Also, can someone else confirm if this works before I actually try touching it to it? I'd really rather not make things worse if that can happen :P. As for the CPU, that brings me back to "which black thing on the mobo is it."
there's multiple pins on the CPU for sound, the only changing is the mixing of them.. if you can atleast get sound from one of the pins by touching the pin on the RCA jack, then the sound is there, but the mixing is dead..
QuoteDon't worry... this is just ordinary lint-free cloth like CD wipes. While something along the connection may have been shorted, the NES sound is generated by the CPU and I doubt I shorted the CPU, since again, the system runs perfectly. -
The problem with using a cloth is related to static electricity: wiping the cloth builds up charge that can be fatal to IC chips.
Moreover you could have bent, snapped or accidentally shorted some of the parts that have long metal legs.
Quote
Which cable is the audio cable I should be removing? I actually did see the place where you linked, which let me know where the sound was being sent out, but that cable in those photos is one affixed by the guy doing that mod, not a cable that was already there.
The cable you should be removing is the RCA connector on the back of the NES, like in blackevilweredragon's posted picture
Quote
and if so, where do I plug the other end of the shielded cable into? Can that go directly into speakers, or...?
One end goes into your TV/AMP/Speaker, the tip of the other end goes to your test point on the PCB
Quote
So which thing exactly would I touch the sound RCA jack to? The "sound" thing in the photographs seems to have metal ends on two sides, and be two things to boot.
The sound things you are referring are the 2 resistors?
(http://www.positiveoffset.com/Parts/4.7K-ohm-resistor.jpg)
Check the stereo MOD photo and touch the same places where the modder has soldered the additional wires.
Hey... so I just... had an interesting exercise in cable reach in order to have my NES open, upside down, with a cartridge in the slot, to be able to test this. (It didn't help that there wasn't much separation allowed between the two leads of a "two head" RCA cable)...
First - the cable is fine. Tested it with a camcorder and the sound and the video were both transmitted to the PC... including the oh so joyful feedback when I brought the camcorder too close to the TV. :P
Well, I have good news, I think. Possibly a question mitigating that good news, though.
Those two resistors...
http://www.raphnet.net/electronique/nes_mo...ges/connect.jpg (http://www.raphnet.net/electronique/nes_mod/images/connect.jpg)
On the side of them that is the upper part of this picture (the side where a letter and a number are printed, not the side where the 100 is printed) I get sound out of both of them. I used Ghosts n' Goblins as a test case in stage 1 and I got a majority of the music and sfx on one of them and some of the accompaniment on the other (I'm familiar with the NES sound registers from NSF stuff, so I'm aware of the nature of the separation I was hearing). Anyway, so that's good news, I got music and sfx off the board.
The question is this, though. In the stereo modding picture he had stuff connected to both sides of the resistors. I checked both sides of each resistor, and as I said, the lettered side got me sound but the side numbered 100 did not (at first when I checked I realized my guy had just died so it was intentionally silent, so I waited until I was on the next life and tried again). Am I supposed to get sound off both ends of each resistor, or is this normal? Are the two other ends that DID get me sound ALL five channels (square1,square2,triangle,noise,dpcm)... aka all my sound is alive... or is "part" of my sound dead? That's my question. Ghosts n' Goblins stage 1 SOUNDED pretty complete when I imagined mixing the two signals I got in my head, but that's not exactly a scientific verification for me :).
BTW... in the off chance that the other end was power... I didn't short the sound since I tested the lettered side again after retesting it, and yup, had sound. So no worries about shorting there.
Lastly, the question that, should there be an easy answer, will end my woes once and for all... now that I know my sound is alive (and hopefully pending answer to the above question ALL of it is alive)... where do I look from here to see where the signal death occurs? And when I find the spot (depending on whether it's on a printed path or in a component) what can I do with it to fix it? Multitudes of printed paths on the circuit board don't exactly want me touching the RCA tip to any of it unless I know exactly which gold line to touch, as you can imagine :). Also I'm not sure, given how many circuit paths there are, which component the sound goes to next, though that seems to be the logical next place to check.
Lastly, I realize I'm a difficult nut to crack. I sound so needy, and I'm so personally unfamiliar with the inner workings of the board despite knowing computing otherwise... reading other threads here, I'm like a help me case where there isn't much I seem to know how to do on my own unlike many other things here :). So I wanted to thank EVERYONE who has helped me in this thread so far (and anyone and everyone who ends up replying after this) for the help I've been given, whether this problem gets solved or not.
Incidentally, this was finally the nut that cracked that told me I should learn some basic soldering, to the point that I tried to find if the school I teach at has a basic electronics class that covers soldering that I could take as a "taught" introduction before I go wild with a soldering iron. Oh, and if I need to use a soldering iron for this project for the time being, I'll take the instructions given for what to solder where and go to my friend who KNOWS soldering with those instructions rather than risk my NES further. :)
Relax, Ismail. I don't have the knowledge to help you with your specific problem, but I can tell you that you're asking the right questions in the right way. The fact that you're willing to take risks and that you're willing to do your own work is a big plus and earns our respect. I perceive you as needy or annoying in any way, and I'm actually learning a lot by reading your posts. So relax, and in a minute 'dragon will be along to tell you what's what. :)
-KKC, who thinks we need more positive reinforcement around here...
I remember testing directly on the pins, and getting sound.. So good, the CPU's sound generating circuit IS infact working properly, but the mixing is not...
Ok, I just tested it.. On mine, there is no audio PAST the resistors either...
Do me a favor, just for the heck of it, can you try the RF output just in case? If the RF output don't work either, then I will have to trace the circuit on mine for other points for you to test...
Quick Question, do you have a multimeter, and do you know how to use it? If so, I am willing to have you trace some circuits on the AV module box (first step)...
If you do have a multimeter and can test it, do this for me..
Put a multimeter in the diode setting, or resistance setting (2000 or 2k)...
It should read around what my multimeter says.. If you have a hard time getting a reading with the probe in the RCA jack, do what I do sometimes, but a little bit of tin foil around the probe, and put that in the hole, allows it to get better contact...
http://blackevilweredragon.spymac.com/NESsound/1.jpg (http://blackevilweredragon.spymac.com/NESsound/1.jpg)
http://blackevilweredragon.spymac.com/NESsound/2.jpg (http://blackevilweredragon.spymac.com/NESsound/2.jpg)
http://blackevilweredragon.spymac.com/NESsound/3.jpg (http://blackevilweredragon.spymac.com/NESsound/3.jpg)
BEFORE YOU DO THAT: Please, discharge the NES.. Turn it on with no power brick on it, the power LCD should flash quickly once.. Once the LED is out, done, it's discharged..
The "side numbered 100" of both resistors is connected to ground.
Besides doing what blackevilweredragon has suggested, please post the photos of your board (use imageshack to host them).
Oh, I wasn't freaked out. I just wanted to apologize for the "Feed me, feed ME!" tone I felt my posts had.
So the "100" side of these resistors really ISN'T supposed to give me any sound? That relieves me quite a bit. I was much heartened earlier today but then got concerned at what might be necessary (like removing and soldering new resistors in) if one side was broken.
I don't have a multimeter with me, but I'm finding out if anyone I know does.
I'll check the RF switch thing this weekend... hopefully tomorrow, Sunday if absolutely necessary.
For photography purposes, what should I focus on and make sure isn't blurred or obstructed by flash reflection?
Above is me... HAVE to remember to type the name in.
QuoteOh, I wasn't freaked out. I just wanted to apologize for the "Feed me, feed ME!" tone I felt my posts had.
So the "100" side of these resistors really ISN'T supposed to give me any sound? That relieves me quite a bit. I was much heartened earlier today but then got concerned at what might be necessary (like removing and soldering new resistors in) if one side was broken.
I don't have a multimeter with me, but I'm finding out if anyone I know does.
I'll check the RF switch thing this weekend... hopefully tomorrow, Sunday if absolutely necessary.
For photography purposes, what should I focus on and make sure isn't blurred or obstructed by flash reflection?
Focus on both the bottom of the AV module, and the bottom side of the NES motherboard... (i want to see the traces, and see if they are in tact)...
This is possibly a premature update, but just so you know:
I tested the rf switch jack and it's silent that way too.
I found that I need to tighten the controller connections inside the system (I once had to do this in the past) because controllers plugged in won't work and the system locks at points where it actually "wants" controller input... looks like it's not major and will be fixable as soon as I open up... I'll make sure it's okay before I close back up again. Don't worry about that one unless I mention it again :)
Still seeing if anyone has a multimeter. There is the "buying one" option but I'd like to be sure of the need before doing so.
Photography will be done when I next open the system. When you say the bottom of the motherboard, do you mean just the notable side of the motherboard in general or focusing on a particular edge of the relevant "side" of the motherboard?
Depending on what you need, my existing photography may be fine for this.
QuoteThis is possibly a premature update, but just so you know:
I tested the rf switch jack and it's silent that way too.
I found that I need to tighten the controller connections inside the system (I once had to do this in the past) because controllers plugged in won't work and the system locks at points where it actually "wants" controller input... looks like it's not major and will be fixable as soon as I open up... I'll make sure it's okay before I close back up again. Don't worry about that one unless I mention it again :)
Still seeing if anyone has a multimeter. There is the "buying one" option but I'd like to be sure of the need before doing so.
Photography will be done when I next open the system. When you say the bottom of the motherboard, do you mean just the notable side of the motherboard in general or focusing on a particular edge of the relevant "side" of the motherboard?
Depending on what you need, my existing photography may be fine for this.
Pictures of the motherboard should be the "component side", where all the IC's are located.. Try and get a "overview" shot, so we can see the whole board...
For the moment, let me show you the pictures I took before starting this thread in case they're useful. If I need new pictures, let me know. Granted I've tried things since these pictures, but the only things I've tried were to test the resistors and to remove the NTSC sticker you see in these photos. Other than the sticker, it all looks like this.
http://members.cox.net/slipgate/P9040004.JPG (http://members.cox.net/slipgate/P9040004.JPG) - possibly too far away, holistic shot
http://members.cox.net/slipgate/P9040012.JPG (http://members.cox.net/slipgate/P9040012.JPG) - closer up holistic shot
http://members.cox.net/slipgate/P9040006.JPG (http://members.cox.net/slipgate/P9040006.JPG) - extreme closeup of one corner, possibly not needed but kept in if useful
http://members.cox.net/slipgate/P9040010.JPG (http://members.cox.net/slipgate/P9040010.JPG) - extreme closeup of a relevant side... if the orientation obstructs your view rather than just being able to flip vertical I can take another picture from the other side.
http://members.cox.net/slipgate/P9040011.JPG (http://members.cox.net/slipgate/P9040011.JPG) - camera following left a bit to see the power box in the corner and such.
Are those useful? Do they reveal anything? Do you need a better view of the metal AV box? (I never opened it before)
In other news, I may have found a friend (sort of a friend of a friend, really) that fixes stuff all the time (RV's, etc.) and probably has a multimeter, so if he does have a multimeter he also probably knows how to use it and may be able to help me do the testing you want. I'm finding out if he even has one first though.
Being I am not home right now, I won't be of much help for now (ill be back home late tomorrow)...
I'm trying to go through the NES schematics, and figure if there is an easy way to test points with the multimeter.. the one I suggested before, with the multimeter, is the best bet at the time...
The AV box will need to be opened (look at my pics, to see the orientation i had the NES, so you know which side opens, as one side does not open)..
In this picture (http://blackevilweredragon.spymac.com/NESsound/1.jpg) is the little thing pointed at by the red arrow on the right where I should open from? Or is that a multimeter test point?
It's okay if you can't get to it till tomorrow, I probably can't get back to it till then anyway (though I plan to correct the controller issue today, and test while the box is still open to make sure it's fixed).
QuoteIn this picture (http://blackevilweredragon.spymac.com/NESsound/1.jpg) is the little thing pointed at by the red arrow on the right where I should open from? Or is that a multimeter test point?
It's okay if you can't get to it till tomorrow, I probably can't get back to it till then anyway (though I plan to correct the controller issue today, and test while the box is still open to make sure it's fixed).
My bad, forgot, you don't have to open the AV box to do this test, sorry..
Those red arrows, are pointing directly at which point to test with the multimeter...
If the multimeter shows the rating (or close too) mine did (when set to the same settings specified), then the AV box is fine.. the short is somewhere on the motherboard then..
Oh I see, the two cables on the multimeter should be hooked to those two spots.
Are we sure this is a voltage thing? Will there BE voltage in a system that's off and not even connected to power, as well as discharged already? If a component has bricked somewhere like this, will the voltage indicate that?
Also, is that a 5.89 or a 589? I realize there's no decimal there, but I figured it was worth asking in case the multimeter I ultimately get my hands on differs in its display characteristics.
I look forward to narrowing this down :).
I'm still perplexed by the fact that when this problem originated, it didn't exist when I first put the system back together and played it that night but existed the next day. Still, I've determined that it's not on a cartridge, so... :P
(Hah, I should find out what Heavy Barrel actually sounds like... it was the first game that was silent the day we discovered this issue)
QuoteOh I see, the two cables on the multimeter should be hooked to those two spots.
Are we sure this is a voltage thing? Will there BE voltage in a system that's off and not even connected to power, as well as discharged already? If a component has bricked somewhere like this, will the voltage indicate that?
Also, is that a 5.89 or a 589? I realize there's no decimal there, but I figured it was worth asking in case the multimeter I ultimately get my hands on differs in its display characteristics.
I look forward to narrowing this down :).
I'm still perplexed by the fact that when this problem originated, it didn't exist when I first put the system back together and played it that night but existed the next day. Still, I've determined that it's not on a cartridge, so... :P
(Hah, I should find out what Heavy Barrel actually sounds like... it was the first game that was silent the day we discovered this issue)
the multimeter won't be measuring voltage, but it will be measuring resistance..
if there is complete resistance (no connection), it will read a "1", if there is no resistance "a straight connection between those points", it will read a "0".. but you should receieve a resistance about what I got, because there is parts between those pins (amp, RF modulator, etc), so it should be about half resistance.. but if you get complete resistance (multimeter doesn't change at all and stays showing a "1", then the AV module is the cause for no sound, and that board needs to be looked at..
The video and power and RF and such work, as you know. Will the sound not working still potentially make it be a "1" reading despite the rest being okay or will the fact that most of the stuff in there is definitely okay possibly corrupt the result?
Also, what are the chances that it recognizes the sound isn't working in terms of resistance but the actual cause is before it gets into the AV box? Will the AV box have a regular resistance result for sure as long as the problem isn't from it?
Did those sentences make sense for what I'm asking?
Anyway, looking into getting the whole multimeter thing. That admittedly may take some time as one friend asks another :).
QuoteThe video and power and RF and such work, as you know. Will the sound not working still potentially make it be a "1" reading despite the rest being okay or will the fact that most of the stuff in there is definitely okay possibly corrupt the result?
Also, what are the chances that it recognizes the sound isn't working in terms of resistance but the actual cause is before it gets into the AV box? Will the AV box have a regular resistance result for sure as long as the problem isn't from it?
Did those sentences make sense for what I'm asking?
Anyway, looking into getting the whole multimeter thing. That admittedly may take some time as one friend asks another :).
This test is just to narrow down the possibilities.. I admit, it isn't a perfect test, but it does help...
If it reads a 1, that means the AV box itself has a short.. If it reads the normal resistance, close to mine, that means the AV box is fine, and there's a short on the NES motherboard...
Of course, it could show a good reading, but still have a problem in the AV box, but from my experience, highly unlikely...
Make sure you have the probes exactly how I have mine, meaning the red where my red was, and the black where my black was... i haven't tested it the other way around, but if the AV box has a diode, you'll read a false positive...
Well, I'm investigating if the person who possibly has a multimeter can possibly come help me out in the next couple of days sometime.
I was thinking about what I can do until then. Although the short is possibly in the AV box, if you can find any other points to test along the motherboard that might be something I can do until this guy can come over (again assuming he has a multimeter). I realize that puts some work on your shoulders... but I was just thinking out loud of something I can do over the next few days rather than sit on my own butt. :) We can just wait on testing this too.
So did the pictures communicate anything? Do you need pictures with the motherboard flipped around so you can see that side of it better? I'm guessing nothing looks out of the ordinary to you.
Actually, since you have the pictures here, let me ask: Are those red spots normal? In http://members.cox.net/slipgate/P9040012.JPG (http://members.cox.net/slipgate/P9040012.JPG) there's a red spot along the silver edge of the motherboard (lower right corner in our viewing), and another one on a brown doohicky (I don't know exactly what it is, sorry :P) that's to our (viewing) right of the external port that's on the bottom... there's another also... it's on the far side so you may not see it well, but there's also a red spot on another brown doohicky near the AV box... the one to our right of it and a little down. You can see it as a tiny speckle of red because of the extreme vertical angle. They don't seem to be something to wipe off, and I'm not sure they're OF concern because I *think* (but I can't be sure) that I've seen them before anyway. They aren't literally the thing fried or something are they? I just remembered them again looking at my picture.
the brown things are ceramic disc capacitors..
i think those just show test passed at the factory when it was built (from a red marker)...
the pictures, from what i saw, show it's ok... the other person who requested the pics shoulld come around and check himself... there's nothing i can think of to check right now...
i gotta head out, heading to seaworld, so i will be back later in the day...
I've checked the photos and found nothing wrong in them, a further test with the RCA audio cable (poking in just before the AV box), would rule out the possibility of a damaged board. (Still the problem could be in the AV box)
BUT...
Looking at what happened with the ant, it seems that in case of irregular power supply the NES cuts out the audio but still works.
Since the audio was working right after the cleaning, I think that the problem would be either in the power supply or maybe in the cartridge connector.
QuoteIf it reads a 1, that means the AV box itself has a short..
A "1" on the display would mean that the value measured is outside of the range, it could also mean the the circuit is open, but not that there's a short.
So where should I poke the RCA tip at just before the AV box? Which spot? Is the mixing done before the AV box or in it?
Well, by the power supply do you mean the AC adaptor cable or, again, the AV box? I do have a replacement cartridge connector I bought once upon a time and then first cleaned my cartridge connector personally... seeing how well it worked, I decided to save the replacement connector for when cleaning wouldn't solve the problem. I'm not convinced that's the issue here just yet, but if it proves to be the issue I'll try replacing it at that time.
Either way, a "1" would be the undesirable result and tell me potentially where the problem is, right?
Believe it or not, I was doing a little unrelated reading (I remembered that the triangle wave of the NES was used as "bass" and was trying to remember what the square waves generally got used as) and I found out which component is the last one before the sound goes into the AV box. It's the resistor marked FC1 just near the AV box. When next I open the system (which may be tomorrow evening just due to priorities with work... I'm also going to save controller correction for then) I'll test that tip with the RCA jack. It'll probably be an easier reach since it's actually NEAR where the video plug is plugged in.
I must say I'm curious as to whether I'll hear the sound or not. :P I'm wondering if the fix job will be easier if the break is before that or after that, since I don't know what kind of component replacement/rerouting options one would have in either case.
Ironically enough I got the information from an article I read about stereo separation on an NES YEARS ago - which died at the original link but was reprinted by the folks from gamesx.com here: http://www.gamesx.com/wiki/doku.php?id=av:...o_sound_for_nes (http://www.gamesx.com/wiki/doku.php?id=av:stereo_sound_for_nes)
I'll report my results when I have them.
QuoteI found out which component is the last one before the sound goes into the AV box. It's the resistor marked FC1 just near the AV box.
Well, FC1 insn't a resistor, but you are right. You can tap the signal there or on the AV box.
QuoteWell, by the power supply do you mean the AC adaptor cable or, again, the AV box?
:unsure: I don't know, it could be one or the other.
Do you have another AC adapter to try?
Quote
Either way, a "1" would be the undesirable result and tell me potentially where the problem is, right?
Quote
If it reads the normal resistance, close to mine, that means the AV box is fine
Hey folks,
So I got a chance to do the narrowing down.
Tapping FC1 didn't produce results (other than a bit of a buzz on the wrong side of it or whatever), so the sound dies before then. In trying some other resistors I found between the two sides, I happened to find that R7 and R8 are the two sound channels, still as intact as they were at their originating point. R7 and R8 are visible on http://members.cox.net/slipgate/P9040011.JPG (http://members.cox.net/slipgate/P9040011.JPG) near the communication port on the bottom of the system. It's "above" the communication port in this image, but if you were to orient it so that the text printed on the motherboard wasn't upside-down it would be below. That's where I was able to tap and get sound still, from both channels. So the point of break is somewhere between those two, either that or at FC1 itself granted but you know what I mean. I'm not sure what else and where else I can successfully tap from here.
Should the AV box multimeter test still be done? Is there perhaps another spot on the motherboard that should be tested instead now? I'm just wondering if the multimeter is still relevant now that I've determined it isn't the AV box. I imagine it could be used to determine the resistance somewhere else but where to check would be good. (I have the potential opportunity to meet with the friend that has it tomorrow night, but if there's no definite idea of when to test then I'd just meet with him later rather than meeting with him needlessly)
Anyway, now that we have a general locality, what sort of procedure would hypothetically be involved in fixing it? Is this likely a component replacement, or is it likely a "put a little solder down to have a communication pathway become open again," OR is it more likely that I'd try to attach something to R7/R8 to bypass the faulty part?
I'm going to go see what Heavy Barrel sounds like before I close the thing.
I'm going into my NES right now..
A resistor shouldn't be labeled FC anything.. A resistor is going to begin with an R.. what you tapped is something else.. I will test it myself, and see what the FC is..
Well it is the sound point, as confirmed here and by others, in that it normally has the final mixed audio before it goes into the AV box.
See if you find any multimeter test spots or sound signal spots after R7/R8.
No, don't bother with the AV box test, the problem isnt there.. It may be the audio preamp...
This is the preamp chip.. TEST here.. One pin is the amped pin, and the other is the unamped pin... If you get audio from the unamped pin, but nothing from the amped pin, the preamp is dead. (the unamped side will be soft to hear, so you may need to raise the TV volume, I had too)..
http://blackevilweredragon.spymac.com/NESpreamp.jpg (http://blackevilweredragon.spymac.com/NESpreamp.jpg)
(Hint: The amped pin, goes to FC1.. I know FC1 is the audio spot, but it's not a resistor..)
FC1 is a Ferrad Capacitor, i think...
Neither the unamped pin nor the preamped pin get me anything.
QuoteNeither the unamped pin nor the preamped pin get me anything.
hmm, ok, so the short is somewhere else.. give me a few minutes to find the next connection to find... (i will use a multimeter for this, but you won't have to, ill have you tap the audio pin on something else)
I would have you try both sides of this capacitor, but it's so tight in there, i worry you may accidentally short something out.. (both sides of it is the audio also, left side is louder (and is a mix of the unamped side), and the right side is softer, and is going right to the unamped pin...
http://blackevilweredragon.spymac.com/captst.jpg (http://blackevilweredragon.spymac.com/captst.jpg)
Both sides of the capacitor are silent. Well, we're narrowing things down at least.
Incidentally, the component you mention with unamped and amped pins is a Toshiba thing for me instead of a Motorola thing, but it's otherwise indentical in placement on the board and in pin arrangement.
FC1 is an L (inductance), the ceramic cap is in parallel to the NOT port (your 'preamp').
The only part remaining between the working (R6, R7) and the not working (the whole preamp thing) is the Electrolytic cap. (C23?)
Still the problem could be power on the 7404.
I'm assuming the 7404 is in the AV box (or is the AV box). I did a quick look just now to see if I could see the capacitor marked C23, and I have to admit I'm not sure where it is. I caught sight of C22, and several numbers below it, and some numbers above it (including a C40 somewhere)... can I get a ballpark on where to look for C23? Also... if it's an electrolytic cap, does that mean I wouldn't want to touch with with anything? :P
Ismail (who types his full in the Name field for the sake of consistency)
QuoteI'm assuming the 7404 is in the AV box (or is the AV box). I did a quick look just now to see if I could see the capacitor marked C23, and I have to admit I'm not sure where it is. I caught sight of C22, and several numbers below it, and some numbers above it (including a C40 somewhere)... can I get a ballpark on where to look for C23? Also... if it's an electrolytic cap, does that mean I wouldn't want to touch with with anything? :P
Ismail (who types his full in the Name field for the sake of consistency)
:lol: 7404
Look here:(http://blackevilweredragon.spymac.com/captst.jpg)
It's the IC marked MC74HCU04 ;)
C23 is the blue cilinder between the 7404 and the big IC.
Be careful, i'm not sure if that's the right cap, I only have the schematics, don't have a NES board to check.
So the 7404 is the thing that does the amping itself? It's not a Motorola for me, but most of that number combination (barring the starting letter not being an M and such) is the same.
So I should test the blue cylinder's two metal legs, then, right? Well, I tested both of them and got no sound. After all of my tests I always verify that sound is still on R7/R8... and it is. (Just making sure I don't short anything... case in point, trying to reach the cylinder from the other side got me to reset the system)
Maybe there's something other than that blue cylinder? But anyway, that blue cylinder isn't the problem. It is next to the long IC with many many pins however, and that long IC is one of the most noticeable things between R7/R8 and where we're poking right now. Should I look there next?
Should I test that IC with a multimeter perhaps?
According to the schematics, the 12K and 20K resistors (R7 and R8) are connected together and with one side of the capacitor.
http://www.neshq.com/hardgen/schem4.jpg (http://www.neshq.com/hardgen/schem4.jpg)
The other side of the capacitor goes to pin #11 of the 7404.
If you have audio at the common point of the 2 resistors (actually 3 resistors because there's another 20K res), then you HAVE to have audio also on one side of the capacitor.
BUT... I don't know if that's the right capacitor, and I don't know if you have poked the audio on the common side of R7 and R8 or on the other side.
Poking on the other side is the same thing as poking on the 2 resistors (R3,R4) where you got your first positive result, but the 2 audio channels are separated, still not mixed.
I need blackevildragon to check his board and confirm the signal path.
Since you have the NES open, have you tried exchanging the cartridge connector?
QuoteShould I test that IC with a multimeter perhaps?
Have you got a multimeter now?
QuoteAccording to the schematics, the 12K and 20K resistors (R7 and R8) are connected together and with one side of the capacitor.
http://www.neshq.com/hardgen/schem4.jpg (http://www.neshq.com/hardgen/schem4.jpg)
The other side of the capacitor goes to pin #11 of the 7404.
If you have audio at the common point of the 2 resistors (actually 3 resistors because there's another 20K res), then you HAVE to have audio also on one side of the capacitor.
BUT... I don't know if that's the right capacitor, and I don't know if you have poked the audio on the common side of R7 and R8 or on the other side.
Poking on the other side is the same thing as poking on the 2 resistors (R3,R4) where you got your first positive result, but the 2 audio channels are separated, still not mixed.
I need blackevildragon to check his board and confirm the signal path.
Since you have the NES open, have you tried exchanging the cartridge connector?
QuoteShould I test that IC with a multimeter perhaps?
Have you got a multimeter now?
shoot, i just put the thing back together after stereo modding mine, and the screws i have holding the case together like breaking and leaving the screws head missing...
sorry, I wasn't thinking :( does someone else here have an NES and knows how to use a multimeter?
Multimeter: Not at present, but the access with the person exists if needed.
Now, you say R7 and R8 should give me sound on both sides? I do remember getting sound on one side but I don't think I got sound on the other side... I assumed that was a case of a ground like with R3 and R4. Should I be getting sound off the extra resistor of R9 or not?
I haven't changed the cartridge connector yet, because I seem to be narrowing on the problem being elsewhere.
dragon: If you stereo modded yours, that just means you tapped R3 and R4, not that you stopped it from going onward to R7/R8 etc. In fact, I'm pretty sure the mono audio will still be at FC1 and everywhere prior to that for that matter. So you can still test the path. As for the case... uh, you should be able to get six new screws... what did you do that has your screws breaking?
Quotedragon: If you stereo modded yours, that just means you tapped R3 and R4, not that you stopped it from going onward to R7/R8 etc. In fact, I'm pretty sure the mono audio will still be at FC1 and everywhere prior to that for that matter. So you can still test the path. As for the case... uh, you should be able to get six new screws... what did you do that has your screws breaking?
oh i know it can still be tested, but the screws are a pain, they are weakened from age.. if i try to unscrew them again, the heads break off, then i can't get the NES open again.. (2 of the screws when i opened my NES for this stuff, broke apart, and im afraid the rest will too)
Ismail: cam you do a quick photo of R7 R8 from above?
QuoteNow, you say R7 and R8 should give me sound on both sides?
There shoud be separated audio on one side and mixed audio on the other (common) side.
I wasn't able to suppress the flash on my camera even if I *wanted* to, so there were several crap shots before I luckily got this high-fidelity image of what you want.
http://members.cox.net/slipgate/P9180041.JPG (http://members.cox.net/slipgate/P9180041.JPG)
R7 and R8 work on the side numbered 20K and 12K. If I put the audio tip in just the right spot between the two on that side, I get the mixed final audio due to the tip touching both simultaneously, but if I touch just one of the two of them, I get the separate two channels. On the side actually labeled R7 and R8, I get nothing. I get nothing on either end of the R9 resistor.
Where should the mixed audio on the other side be coming out of, exactly?
BTW, that upload failed 22k or so short of where it should've, but the only part of the image that doesn't show up as a result is outside the scope of the NES in the picture.
Answer me this: Can I test those resistors that work on one side and not the other with a multimeter? How would I test them?
You know, it may just be the camera, but those resistors look like they have a cold solder joint..
Well, they've never actually been soldered (after the system's manufacture in 1987/88 anyway) but looking at them I did wonder if they were somehow deficient. However, there was dimness for the 12k resistor on the side that worked fine and no dimness on the nonfunctional side for R9 and R8 (the 12k). The nonfunctional side of R7 is dimmer, though. I went back down just now with a small penlight flashlight and shone the light on them from a little to the side and down... they all seemed to similarly reflect though that might be a case of massaging the lighting until I was satisfied they were reflecting. Without the penlight, they seem to all reflect the light naturally on the nonfunctional side when I'm looking at that side head-on, but when looking from the side where the #k is printed the R7 side seems dim while R8 and R9 seem to reflect better. This may be due to lighting situations/my big head, though. The 12k side of R8 reflects like the others (as long as I make sure my head isn't in the way, because the nearest ceiling light happens to be in that direction) but when looking at it from the R side seems a bit dimmer... this may be due to simple lighting/my head once again though. The thing is, the 12 side of R8 works perfectly. Sandwiching the RCA tip just between the 12k and the 20k there gives me full sound (incidentally, although it hasn't been amplified yet, it seems to me to be at the full volume I normally get out of the system, but I might be imagining that due to time away).
It's possible something happened to the soldering after the fact, maybe? Would tiny dollops of solder solve the problem or just obstruct me from reaching the source of the problem? Do we anticipate that the problem is in the cylinder of the resistor, or is it maybe on the other side of the motherboard where the resistors' point ends come out?
Now, what SHOULD I be expecting here? I mean, R9 didn't do anything for me on either side. Is it supposed to? I'm not sure I should anticipate anything out of R9 or not since I'm getting both audio signals from R7 and R8 collectively. If R9 is supposed to give me sound on either side, that can be chalked up as an issue. If not, that leaves me just worrying about just R7 and R8 then. Which narrows the problem down rather much, but also rather frighteningly as we come to it at last.
(Sorry for the verbosity on dimness and reflection above... I was just trying to be thorough in investigating how the joints looked to me)
Can I test the resistors with a multimeter to see if they give me 1s? How would I do that? Is it possible only 1 is actually broken and is corrupting the signal from the other when things come out the other side? But wait, it's still two tips on the other side...
QuoteWell, they've never actually been soldered (after the system's manufacture in 1987/88 anyway) but looking at them I did wonder if they were somehow deficient. However, there was dimness for the 12k resistor on the side that worked fine and no dimness on the nonfunctional side for R9 and R8 (the 12k). The nonfunctional side of R7 is dimmer, though. I went back down just now with a small penlight flashlight and shone the light on them from a little to the side and down... they all seemed to similarly reflect though that might be a case of massaging the lighting until I was satisfied they were reflecting. Without the penlight, they seem to all reflect the light naturally on the nonfunctional side when I'm looking at that side head-on, but when looking from the side where the #k is printed the R7 side seems dim while R8 and R9 seem to reflect better. This may be due to lighting situations/my big head, though. The 12k side of R8 reflects like the others (as long as I make sure my head isn't in the way, because the nearest ceiling light happens to be in that direction) but when looking at it from the R side seems a bit dimmer... this may be due to simple lighting/my head once again though. The thing is, the 12 side of R8 works perfectly. Sandwiching the RCA tip just between the 12k and the 20k there gives me full sound (incidentally, although it hasn't been amplified yet, it seems to me to be at the full volume I normally get out of the system, but I might be imagining that due to time away).
It's possible something happened to the soldering after the fact, maybe? Would tiny dollops of solder solve the problem or just obstruct me from reaching the source of the problem? Do we anticipate that the problem is in the cylinder of the resistor, or is it maybe on the other side of the motherboard where the resistors' point ends come out?
Now, what SHOULD I be expecting here? I mean, R9 didn't do anything for me on either side. Is it supposed to? I'm not sure I should anticipate anything out of R9 or not since I'm getting both audio signals from R7 and R8 collectively. If R9 is supposed to give me sound on either side, that can be chalked up as an issue. If not, that leaves me just worrying about just R7 and R8 then. Which narrows the problem down rather much, but also rather frighteningly as we come to it at last.
(Sorry for the verbosity on dimness and reflection above... I was just trying to be thorough in investigating how the joints looked to me)
Can I test the resistors with a multimeter to see if they give me 1s? How would I do that? Is it possible only 1 is actually broken and is corrupting the signal from the other when things come out the other side? But wait, it's still two tips on the other side...
if a resistor is working, it will report what the NES motherboard says next to it (if the multimeter is setup correctly to that range)..
How strongly do you feel that the problem is these resistors? Do you also share the opinion that the fault could somehow lie in the power supply or cartridge slot still, or do you feel the problem is definitely localized to here?
So the multimeter will present "12K" and "20K" respectively if they're working? Wasn't I supposed to do a test for between 0 and 1? Is it going to be a different testing mode?
Also, IS R9 going to have sound, or not? And what is meant by the mixed audio on the other side... will it be coming out of one of the pins?
QuoteHow strongly do you feel that the problem is these resistors? Do you also share the opinion that the fault could somehow lie in the power supply or cartridge slot still, or do you feel the problem is definitely localized to here?
So the multimeter will present "12K" and "20K" respectively if they're working? Wasn't I supposed to do a test for between 0 and 1? Is it going to be a different testing mode?
Also, IS R9 going to have sound, or not? And what is meant by the mixed audio on the other side... will it be coming out of one of the pins?
I'm not 100% positive it's the resistors.. if you are tapping the resistor itself, whatever the result to be expected, is what you should get.. As, you are not tapping past the resistor, but the resistor itself... Man, that was hard to explain..
Whatever the multimeter measures, is how much resistance the resistor is having.. If it showed there was a 1, that means that resistor is blocking everything.. If it showed a zero, that resistor isn't working to well, and is just letting everything through..
remember my multimeter had a number in the 500's? because that's the resistance for that resistor, it was the norm.. now I don't remember what setting the multimeter was on at the time, but the number wasn't in 500's, more like add some zeros (depending the setting it was on)..
I'm going to wait a couple days on this multimeter thing. Maybe get a chance to do it Tuesday of next week at latest, maybe get to do it sooner. Just kind of busy also, which I'm sure you can appreciate as well.
I guess I'm just trying to be clear on where the points from the multimeter should be attached, what the setting should be, and what the reading should or should not be. Maybe this'll be evident to my multimeter-using friend when he reads these messages, but just in case it isn't, I'd like to have the info on what exactly to look for and how when I do have the small window of time I can meet with him to do this in.
QuoteI'm going to wait a couple days on this multimeter thing. Maybe get a chance to do it Tuesday of next week at latest, maybe get to do it sooner. Just kind of busy also, which I'm sure you can appreciate as well.
I guess I'm just trying to be clear on where the points from the multimeter should be attached, what the setting should be, and what the reading should or should not be. Maybe this'll be evident to my multimeter-using friend when he reads these messages, but just in case it isn't, I'd like to have the info on what exactly to look for and how when I do have the small window of time I can meet with him to do this in.
the NES motherboard says what the multimeter should say, numbers like "20k", thats the resistance the resistor has, and the multimeter should show something similar..
you just connect the probes to, i think either end (someone correct me if I am wrong!)... your multimeter friend should easily know how to test it..
I'm looking to see if this friend can come by this weekend to test the resistors.
Let's say they ARE the problem. Let's say that everything else is fine. If the resistors are found to definitely be the problem, with no problem anywhere else... what would I hypothetically do then? Would this go so far as buying new resistors and replacing the ones currently on the board with the new ones?
BTW, on the "making sure no other problems exist" front, I'll probably have the power box tested too... what points should I use to test the AC adaptor plug and such?
Quote
Also, IS R9 going to have sound, or not?
According to the schematics R9 should have audio on both sides, one side would be connected to the expansion connector, while the other would go to the 7404 (via cap).
Are you sure that there isn't sound? The audio level should be less than the other (working) points, maybe if you raise the volume on your TV you can hear something...
Quote
Let's say they ARE the problem. Let's say that everything else is fine. If the resistors are found to definitely be the problem
Resistors seem fine, the only defective resistors I have ever seen were so burned by heat that you couldn't read the color stripes on them.
The only reason why there isn't audio on the 3 res common point is that the point is somewhat connected to ground, how can that be possible... I don't know.:(
blackevilweredragon: I've added the resistors names to the pic below, do you think I'm right? What about my common point grounded theory?
(http://img49.imageshack.us/img49/2964/nesaudiorm2.jpg)
Maybe a photo of the solder side of the circuit board can tell us something, but without a multimeter there's nothing much that you can do...
I have no idea how to read schematics... :blink:
You said:
"According to the schematics R9 should have audio on both sides, one side would be connected to the expansion connector, while the other would go to the 7404 (via cap).
Are you sure that there isn't sound? The audio level should be less than the other (working) points, maybe if you raise the volume on your TV you can hear something..."
Well, do you mean to suggest that the volume goes way down when the two get mixed together? I suppose I can try again at higher volume. Now, to be clear... I didn't hear anything when touching EITHER metal leg of R9. I heard stuff when testing the ends of R7 and R8 that are marked 12k and 20k, but I didn't hear ANYTHING on the other metal leg of those two. When you say that R9 should have audio on both sides, does it not GET that audio until after they go through R7 and R8? Because the other side of R7 and R8 gets me NO audio. Is that because it's ground or is it supposed to get to the other side of R7 and R8 and THEN go to R9? If it's supposed to be heard when I touch the other side of R7 and R8, then that's where the break is occurring since it isn't being heard there, even "before" it gets to R9. If the other side of R7 and R8 ARE just meant to be ground and the audio is supposed to just be at R9 next, then that suggests R9 is the problem and R7 and R8 are fine.
quoting:
"Resistors seem fine, the only defective resistors I have ever seen were so burned by heat that you couldn't read the color stripes on them.
The only reason why there isn't audio on the 3 res common point is that the point is somewhat connected to ground, how can that be possible... I don't know.:( "
So you're suggesting something is wrong with the connection to ground? Are they supposed to be connected to ground, or not?
Just to learn, you say "read" the color stripes instead of "see" them. Is there something meaningful I can get out of looking at the striping?
Regarding the schematics, those schematics themselves are accurate I'm sure. You should know though that R7, R8, and R9 are in a line like three little piggies on the board. R9 isn't "after" R7 and R8 with an obvious "We go to you" connection, it's directly side by side with them. From what I'm being told, R7 and R8 should give me audio regardless of which metal leg I tap. If that's true... well, I get audio on one side but not on the other. If it moves "up" toward R9 after that then it's already broken before it reaches R9.
What do you think of the way the solder joints look? Suggestive of issue now?
I'm not opening the NES up again until Friday or so. I'll do the "super-high awesome volume test" then... and I'm trying to have my friend with a multimeter come by then. Maybe he can make it Friday, maybe he'll make it some other day of the weekend.
I'm going to have him test the power box (both its audio plug and its power, I think... what points do I attach to in order to test the power?) and those three resistors. Anything else we should have him test while we're in there? Since this isn't my multimeter I'd like to get all the meaningful testing done when I do get an opportunity to get at it just so it's not back and forth for some other guy to come to my place (he lives far enough away).
QuoteYou said:
Well, do you mean to suggest that the volume goes way down when the two get mixed together?
Let's put it this way: Signal exits the sound IC with a strenght that's enough to drive the speaker, after the signal has travelled trough a resistor the signal will be less.
So the more resistors the less signal strenght.
Quote
I suppose I can try again at higher volume. Now, to be clear... I didn't hear anything when touching EITHER metal leg of R9. I heard stuff when testing the ends of R7 and R8 that are marked 12k and 20k, but I didn't hear ANYTHING on the other metal leg of those two.
Ok, It is possible that on the other legs the signal was so muted that you couldn't hear it.
Quote
When you say that R9 should have audio on both sides, does it not GET that audio until after they go through R7 and R8?
Yes
Quote
So you're suggesting something is wrong with the connection to ground? Are they supposed to be connected to ground, or not?
Just to learn, you say "read" the color stripes instead of "see" them. Is there something meaningful I can get out of looking at the striping?
They are **NOT** supposed to be connected to ground, connecting them to ground will ZERO the signal.
The value of a resistor is written with color rings where each color equals a number so black=0, brown=1...
Anyway this is not important, resistors are fine, forget about them.
Regarding multimeter tests:
Check voltage ont the power plug, the value should match (or exceed) the value stated on the label.
Check voltage on the NES, verify that there are 5v on the ICs.
Check the AV box as suggested by blackevilweredragon.
If everything is OK then measure the resistance between R7, R8, R9 and ground: keep one of the probes touching the silver edge of the mainboard and with the other probe touch the resistors. The display should never be = 0.
If your friend can read the schematics, then show him the piece of schematic below and follow all the signal path.
I've tried a little experiment with a famiclone (I don't own a real NES anymore): I opened it and looked at the audio parts of the PCB.
Part of the circuit looked exactly as the NES, the resistors have the same values, so I tried with the RCA audio cable to poke the resistors.
I got single channel audio from the 2 100 Ohm resistors (like you did), then I tried the 12K and 20K and got mixed audio in the common point (where you didn't get sound), but the volume was VERY VERY VERY low as I expected.
The rest of the circuit is completely different, so I can't test it further and help you with that, but if you happen to get low volume audio as I got, then you should go back and test the 7404 as blackevilweredragon suggested.
Well, while there is a possibility of my not hearing "too-quiet" audio, I did have the volume up fairly well.
It was up high enough that if I had been playing Excitebike 64 I would've wanted to turn it down because of the revving sounds, though for most games it's the volume level I play at. But then, I don't know how weak the signal truly becomes. How much did you have to jack your volume up on your own TV before you heard it? If it was just a few points up, then I probably would've heard SOMETHING... if it was a whole lot, then I'll try it.
So I should first see if the other leg of R7 and R8 has single-channel too-weak audio? Or should I go straight to R9?
Ismail
I had the TV volume set to less than 1/10 th of max and I could hear the unmixed audio perfectly, to (barely) hear the mixed audio I had to go to 50% of max.
QuoteSo I should first see if the other leg of R7 and R8 has single-channel too-weak audio? Or should I go straight to R9?
You can't have 'single-channel too-weak audio', those points are all connected together. You can only have weak mixed audio, so each point will be the same.
But to avoid further confusion with R9, that has a side common with R7/R8 and one side connected to the exp. connector, please do your test touching R7 or R8.
Due to scarcity of communication, the multimeter test has been postponed to Tuesday for now. However, in its place, I got the extra resistor testing done.
To quote Nuuma from before:
Quote
According to the schematics, the 12K and 20K resistors (R7 and R8) are connected together and with one side of the capacitor.
http://www.neshq.com/hardgen/schem4.jpg (http://www.neshq.com/hardgen/schem4.jpg)
The other side of the capacitor goes to pin #11 of the 7404.
If you have audio at the common point of the 2 resistors (actually 3 resistors because there's another 20K res), then you HAVE to have audio also on one side of the capacitor.
BUT... I don't know if that's the right capacitor, and I don't know if you have poked the audio on the common side of R7 and R8 or on the other side.
Poking on the other side is the same thing as poking on the 2 resistors (R3,R4) where you got your first positive result, but the 2 audio channels are separated, still not mixed.
Well, I tested R7 and R8 with the volume bleedingly loud. This was painful on the side that it was single-channel audio, let me tell you (because of how freaking loud it was)... anyway, I've discovered that those resistors are okay. On the "empty side" of R7/R8 (so named because I thought they were dead before) I get low-volume mixed audio. I get the same on both sides of R9.
After that, it goes to one leg of the capacitor near the amp thing, right? Well, I also heard this super-weak mixed audio on one leg of that cap (but not the other, though judging from the above that's normal).
I also heard this weak audio going into the pin you called the unamped pin. I got nothing out of the amped pin side of it.
I believe this identifies the problem, heh. Even so, I'll probably have my friend test the power output of the system just to make sure my system is otherwise healthy after all the crap I've been doing with it.
So, what solutions should I be looking into now? Does the 7404 do anything OTHER than the amping of audio? If not, can I just.... "reroute" so to speak? Or is it not that big a deal to repair or replace this component if entrusted to properly trained people?
Apologies if the above has been told to me already, it's just getting to be a long, detailed thread :).
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I also heard this weak audio going into the pin you called the unamped pin. I got nothing out of the amped pin side of it.
I believe this identifies the problem, heh. Even so, I'll probably have my friend test the power output of the system just to make sure my system is otherwise healthy after all the crap I've been doing with it.
There still can be something faulty after the 7404...
That is the thing that puzzles me: the other gates of that chip are still working, it's strange that only one of the gates is dead.
Moreover if the problem was caused by (lack of) power, the other gates should be affected as well.
QuoteDoes the 7404 do anything OTHER than the amping of audio?
It does other things: for example it handles the clock of the security chip.
QuoteSo, what solutions should I be looking into now? If not, can I just.... "reroute" so to speak?
I think the simplest solution would be to do the stereo MOD, you just have to add the 2 RCA connectors and solder 3 wires.
QuoteOr is it not that big a deal to repair or replace this component if entrusted to properly trained people?
Replacing the 7404 with the right tools is a 5 minutes job, a technician can also check if the part is really defective or the problem is somewhere else.
QuoteThere still can be something faulty after the 7404...
That is the thing that puzzles me: the other gates of that chip are still working, it's strange that only one of the gates is dead.
Moreover if the problem was caused by (lack of) power, the other gates should be affected as well.
Well, either you or blackevildragon earlier stated that the amp itself was the problem if I was getting audio on the unamped pin but not on the amped pin, which is what is in fact happening. I don't think the unamped pin being fine necessarily implies anything since it's going IN on that pin and I'm intercepting it before it gets in there. The amped pin side is not coming out, though. I don't think the system isn't getting the necessary power.
The fact that the 7404 has another duty, one that seems to be just fine (after all, I'm not getting infinite resets except when the cartridge slot casing jiggles and fudges the cartridge's proper connectivity) does puzzle me though... how can a component be "partly" fine? I first came here * because* Iwas skeptical that the sound itself could be fried since it was on the processor and the system itself seemed fine, so the idea that the 7404 is "partly" bad and not fully bad is also similarly strange.
I wonder if maybe just the amped pin is shorted... something that maybe happened when I was first mucking with the system?
Regarding the rest of what you said: So the simplest solution is the stereo mod, even though replacing the 7404 is a 5 minute job? Hmm. Well, let me ask you... I've noticed that blackevildragon and I have different 7404's (different manufacturers... one of us was Motorola, the other was Toshiba - I'm not inclined to check the photos right now to figure out which was which). How interchangeable are these with 7404's I could buy "off the shelf"? Is this not an NES custom part, is it really identical to replace it with another of the same kind of chip? (I know that many parts, including the main 6502, can't just be replaced with off-the-shelf parts for a variety of reasons... in the 6502's case because of the sound)
Who would this hypothetical technician, who would know what was wrong and what wasn't, be? Are we talking electricians? Are we talking my friend? Or are we talking a specialist?
QuoteQuoteThere still can be something faulty after the 7404...
That is the thing that puzzles me: the other gates of that chip are still working, it's strange that only one of the gates is dead.
Moreover if the problem was caused by (lack of) power, the other gates should be affected as well.
Well, either you or blackevildragon earlier stated that the amp itself was the problem if I was getting audio on the unamped pin but not on the amped pin, which is what is in fact happening. I don't think the unamped pin being fine necessarily implies anything since it's going IN on that pin and I'm intercepting it before it gets in there. The amped pin side is not coming out, though. I don't think the system isn't getting the necessary power.
With "after the 7404" I meant that some of the parts that come after the 7404 (in the audio path), can be faulty and can bring down the audio.
It was blackevildragon who suggested checking the 7404, so it's better if you ask him for assistance ;)
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how can a component be "partly" fine? I first came here * because* Iwas skeptical that the sound itself could be fried since it was on the processor and the system itself seemed fine, so the idea that the 7404 is "partly" bad and not fully bad is also similarly strange.
Please forget my comment about parts partially defective.
It IS possible that a part is partly defective and still the rest of the chip is working normally, happened to me in a few occasions.
What I meant to write is: I find difficult to believe that the problem was caused by insufficient (or not normal) power, when the rest of the gates are working.
Quote
Regarding the rest of what you said: So the simplest solution is the stereo mod, even though replacing the 7404 is a 5 minute job?
A 5 minutes job with the right tools and a bit of experience.
Quote
Hmm. Well, let me ask you... I've noticed that blackevildragon and I have different 7404's (different manufacturers... one of us was Motorola, the other was Toshiba - I'm not inclined to check the photos right now to figure out which was which). How interchangeable are these with 7404's I could buy "off the shelf"?
It is not a custom part and you can replace it with another chip, with the same specs, built by whatever manufacturer you want.
The "74" family of chips are the basic components upon which the digital circuits are built.
In your case the name is composed by "74" + technology (In your case HC = High speed CMOS) + name of the device (04 = hex inverter).
Here is a page with a few links to manufacturers + datasheets:
74hcu04 (http://www.datasheetcatalog.net/cgi-bin/helo.pl?field=Nume&type=C&text=74hcu04&producedby=&action=Search)
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Who would this hypothetical technician, who would know what was wrong and what wasn't, be? Are we talking electricians? Are we talking my friend? Or are we talking a specialist?
The technician who could replace the part in 5 mins is someone who can solder/desolder ICs. Can your friend do that?
Probably an electronic repair shop can do it, but it could cost you more than a new NES.
Well, with the information I have, I think what I'll do when I first get together with him is to again verify that the unamped pin works but that the amped one doesn't. Then I'll get some multimeter testing done on the power box, the 7404, and a few other places.
He might know this, but what sort of ranges should the multimeter be set at, and what two points should it be affixed to, for the 7404, the resistors, and so on? I won't be able to go running back and forth and catch someone here while I'm actually together with the guy, so having this information beforehand will mean that the trip will actually get some meaningful results :).
You say it would cost more than a "new" NES... do you mean another used one right now, or do you literally mean it would be 100 dollars or more?
Ismail
By the way... to go back to something I said at the beginning of this thread... is it possible that the shorting was due to the Honeybee converter? I'm just wondering if the Honeybee converter is something I should consider off-limits and never use again assuming I fix this, or if I shouldn't worry and freely use it. I was just reading about inverters on Wikipedia, and if Honeybee converters and illegit cartridges use 5volt shocks to bypass the security chip... is that possibly what happened?
Quote
You say it would cost more than a "new" NES... do you mean another used one right now, or do you literally mean it would be 100 dollars or more?
I meant an used NES. Is it really possible to find new ones?
Quote
I was just reading about inverters on Wikipedia, and if Honeybee converters and illegit cartridges use 5volt shocks to bypass the security chip... is that possibly what happened?
Your security chip is still fine so the converter is harmless, but you might consider posting the same question on the nesdev hardware forum (nesdev.parodius.com).
Since you are going to work extensively on your NES, as a last measure please try to swap the cartridge connector.
Hey folks,
I have some testing results.
They seem to indicate that there is a potentially fixable problem here by replacing components, but that something might still be fishy. Something very bad DID happen to my NES, seemingly without my doing.
First of all... R7-R9 seemed to test at numbers I didn't quite understand, but when I told my friend of their supposed voltages, they registered okay to him.
It would appear that the capicator near the 7404 is actually a big part of the problem, more than the 7404 itself is... however, something MAY also be up with the 7404.
The capacitor, when I reread here, apparently is supposed to have audio on both legs. That about right? However, I get 5v on one leg, and .02 volts on the other. That seemed to be a problem... it seemed like the power wasn't flowing back down the other leg the way it should be... both should be 5v in the guy's estimation, but we decided I'd run those results by here to see if it was in fact SUPPOSED to be that way. Again, according to what I heard before, both legs on the cap should give sound... however, only one does. More strangely, the one that is .02 volts is the one that gives sound, while the 5v one does not. Now... on the 7404... the amped pin provides 5v, and the unamped pin provides .02 volts also. This may be because of what it's getting from the capacitor, though. The 7404 itself is probably fine, because we looked up schematics and tested its own power usage by tapping ground and its power pin with the multimeter and got a normal reading.
My friend at first wondered if maybe such an OVERLY weakened signal was going into the 7404 (due to the cap) that it was TRYING to amplify it but was amplifying nothing. However, I noted that amplifying what little signal it got should at least allow the weak sound already there to still exist instead of dying. Someone here mentioned that they "barely" heard sound from the weak audio signal when at 50% volume... but they heard it, right? My TV, as I realize now, was at a volume of 50 out of 63 to hear anything, and the friend's house I was working at was using a subwoofer that they had to turn down and then adjust back up gradually when we were switching sound test points so as to not blow it... we had to be that loud before we heard anything from the cap or the unamped pin. Somehow, we DID hear from the cap and from the unamped pin despite both being .02 volts. The amped pin was 5v, and as I said, this guy wondered if maybe it was trying to weaken a useless signal, but since we could get something out of it, we weren't sure that was what was happening. So we wondered if MAYBE the 7404 also needed replacement, but it did seem more likely that the cap was having the issue that was then going down the line from there. The 7404 itself got normal power when using its own test points, and as is obvious here (from the fact that we had another friend play Ghosts n' Goblins as we tested to keep sound going) the security chip DOES work.
There are two other things worth noting here.
1) Near the power box - http://members.cox.net/slipgate/P9040012.JPG (http://members.cox.net/slipgate/P9040012.JPG) look at the little green jut that comes down (in this image) and is between the power box and the blue plug along the left side. In person, the silicon here apparently is a little discolored relative to the rest, convincing my friend that some of the area around the power box got really hot and burned a bit. He pointed out some yellowizing as silicon that had bubbled up. Some of this burning may have contributed to the issues I'm having (see #2 below) or it may have just barely been a bullet-dodge.
2) The guy tested the audio plug on the outside... he kind of did this first since I figured we may as well do it. It reported a resistance of 1 when using the points first communicated to me in the image by blackevilweredragon. Now, I remember asking if a resistance of 1 there meant the problem WAS there or was earlier along, and dragon said that as long as a component was fine, even if an earlier component was jacked, it wouldn't list resistance. So anyway, there it is... a 1 resistance. This is possibly due to the fact that the audio signal isn't coming right anyway by that point, OR it may be due to the above burning of silicon. We were curious to test the video plug for a similar 1 rating, since the video plug DOES work, but we didn't know what the other test points out of the four in that little row for those things, and when you don't know which is which the results are hard to take anything from. I do still wonder if the 1 resistance is due to the cap and the 7404, but it is possibly something to check again after/if those components are replaced.
However, the "burning" and such make it sound to me like the problems creeping up aren't really related to my mucking in the NES and were coincidentally not long after I messed with it. The capacitor seems like criminal #1, and we have two other possible criminals that may be exonerated or may be found to also be guilty after criminal #1 is put away.
A stereo mod is certainly a workaround in the here and now, but the burned silicon and how and why the system overheated are important questions to me, as I may just be putting off a system death in progress rather than cheating my way out of a problem. My friend is cautious, but moreover says he doesn't himself have the cold core soldering iron we would need even if we did replace this stuff. (He's replaced caps on an RV a lot... it's just that he wants to play it carefully especially with a board that HAS had burn issues, and he has 99% certainty it's the cap but realizes that due to later issues that might not be the end of the solution).
Oh, and other components aren't an issue. The silicon is very healthy in other regions (he even let me see the yellowing by having me compare the color nearer the processor to that nearer the power box on that jut)... the cartridge connector and so on are fine. He was rather impressed at how much information I had... more than he anticipated... and also appreciated knowing that power irregularities for the NES can kill sound, because it's what prompted him to test voltages on the cap and make sure the 7404 was receiving the power it should.
So, question 1 here, which determines if the cap is at (primary) fault... are the two legs on the cap supposed to read 5 v and .02 volts? (note... all things that read 5 volts for me actually read 5.01, but that was a variance neither he nor I worried about, especially to see them consistently be that)
Question 2 is: If the unamped pin being at .02 volts yet having sound while the amped pin at 5 v not having sound makes sense to anyone, and if his theory is possibly a good explanation or not.
He's pretty much convinced it's the cap, and thinks the 7404 and later are suffering because of it, but he recognizes the silicon burning could've affected a signal path and he'd test the 7404 again to see if that fixes the problem on the unamped pin after replacing the cap.
This is of course getting closer to territory where a "new" NES would be safer, but as long as no money or small amounts of money are the only issue here, I'd like to investigate this problem out to its end for my edification. I've learned a great deal through you guys and through what he showed me that night.
The silver points? That's not "silicon", silicon is in the chips, and is like a dust when exposed to air.. What you are referring to, I believe, is Solder.. And the brownish color isn't burning, that appears to be either flux, or the solder was a Rosin Core Flux solder.. My game console mods always appear that way, it helps the joint stick better.
Even if that's true, I do need to find out what's going on between the cap and the 7404, and the fact that the audio plug is showing me full resistance in the power box might be a problem too even after I address the cap and 7404, or it might go away once I do so.
This thread has gotten so long that I'm pretty sure anyone new is dissuaded from chiming in upon reading it. So I have you and Nuuma, and you have a real NES while Nuuma has a famiclone that may or may not have the same parts at this point in the signal path. Would you be willing to test the voltages on the cap and the 7404 to see if this .02 is regular?
Alternatively if the famiclone also uses a 7404 with a cap passing the audio signal to it, that cap/7404 could be tested.
I don't know how to test caps, I hear it takes big equipment to do that, sadly...
I will try and take my NES apart later today, right now, I'm still just waking up, with a massive neck pain..
Whoa whoa whoa, don't take it apart.
All my friend did was test the voltage with a multimeter. Ground on one wire of the multimeter, and putting the other wire to each leg of the cap in turn.
Also see the voltage on the unamped pin vs. the voltage on the amped pin for you.
But that's later later later. Do a normal day here first.
Thanks.
I'm trying to remember what my multimeter said when measuring the caps in my old Commodore 64.. I remember the reading was out of wack, but the caps were just fine..
So, uh, what's the word?
Are Nuuma and blackevilweredragon still around?
If not, does anyone have an NES that they can test the above capacitor and 7404 on? I need a voltage test, as mentioned on this page of the thread, of the two legs of the capacitor that sends sound into the 7404 and of the unamped pin and amped pins of the 7404.
I need to see if .02 results are normal.
Also... I still want to see if .02 results are normal and if I can address the fault in the system so that I can go back to using its normal external audio plug, but let me ask this while I'm at it:
Is this exactly what I'd be looking for if I decided to just make a workaround?
http://www.radioshack.com/product/index.js...rentPage=search (http://www.radioshack.com/product/index.jsp?productId=2103848&cp=2032058&f=Taxonomy%2FRSK%2F2032058&categoryId=2032058&kwCatId=2032058&kw=shielded+wire&parentPage=search)
(I'm not terribly interested in stereo separation on the NES, and this seems to take two audio points and combine them into one RCA connection)
Anyone still here? I'm just looking for anyone who can tell me if the capacitors should be giving the voltages shown above. You don't even need to read this whole thread, just this latest page.
I have some workarounds in mind, but I do want to see if certain components are faulty by seeing if their readings are what they should be or not.