RGB image issue with Super Famicom :(

[Alcahest]

So there we have the final answer, thanks viletim.
It's a SFC problem with my TV partially responsible as well in the fact that it doesn't like this slightly out-of-spec SFC 240p signal. (even if TV does accept PS1 "240p" perfectly alright..)

Thanks to all of you guys for all these precious infos and help pinpointing the cause.

I will try the LM1881 way, if there is a chance it solves the problem, I want to try.

Then I have another question; isn't it possible to get a cleaner "sync" directly from the insides of the SFC, on a component leg maybe, before it is mixed to the other video components?

Also, would anyone know the use of this : (called "TC1" on the board)
http://videoff7.free.fr/whatsfc.jpg
I found this: http://nfggames.com/forum2/index.php?topic=1036.msg7629#msg7629
Would tweaking this pot have any impact on the problem i'm having? ^^;

See you,

Alcahest

[Silver]

And again, i still wonder, does ANYONE have a perfect image with US SNES or JP SFC outputting RGB to an HDTV/progressive display ?

I don't own a HDTV at all, but I have played a RGB connected snes on one without problems in the past. I certianly did not notice any line issues like you have - can't remember the make.

Another option you have is to use a RGB scaler. Sadly this is probably not very cheap (at least for good quality), and a bit of a shame when your TV has one in-built. You could probably get away with a RGB->VGA scaler too. I have also seen people use a RGB->Component converter on a Snes (although this was because their TV/AV Amp only took Component, not RGB).

Obviously it's not ideal (and perhaps no guarentee that the scaler will not freak out the famicon output too).

I notice some people on the web reporting verical green/yellow colour bands in the middle of the screen on some TV's with RGB famicoms - Samsung mainly I think. Who knows how the upscaler manages to produce that from the input?

I would be curious to know the difference between the ps2 240p and the snes 240p as I can't see that are that many different approaches. Although the ps2 came out waaaaay later than the snes, and they probably had some upscaling digital panels to test with.

[acem77]

i use a snes on my xrgb2 plus that is conected to my samsung dlp and it works great.

[Silver]

i use a snes on my xrgb2 plus that is conected to my samsung dlp and it works great.

Yep, upscalers are one way round the problem. xrgb2(+) probably cheapest around that's regarded as good PQ.

I had read the xrgb2(+) does not support "weird syncs" of arcade boards or genesis, wheras the older model (non-plus) does. Ideally you'd need someone with the same tv to test with and without....

[Link83]

Hi Alcahest,
I know this may seem like an odd (perhaps useless) suggestion, but are you using an Official SNES Power Supply from your country with this Famicom?

I only ask as I have recently been reading of people having video interference problems with many different consoles, and in the end they were all due to cheap replacement power supplies they were using, or poor quailty step-ups/step downs.

Even if it is an Official SNES Power Supply from your country, I would probably still try another one aswell just in case there is a minor fault with the one your currently have.

Maybe something to consider?

(If it is the power supply it would explain why you are having the same problem with two different Famcicoms - assuming you were trying them both with the same power supply.)

[Alcahest]

Hi Alcahest,
I know this may seem like an odd (perhaps useless) suggestion, but are you using an Official SNES Power Supply from your country with this Famicom?

Hey Link, I live in France, so there isn't an official AC adapter for the Super Famicom here.

I only ask as I have recently been reading of people having video interference problems with many different consoles, and in the end they were all due to cheap replacement power supplies they were using, or poor quailty step-ups/step downs.

Yes, I have wondered about this a little in page1, here's what i have.
- 1 sega master system french adapter, outputting DC 9v-1A-9VA
- 1 chinese bootleg super famicom ac adapter which connects to 220v french outlets directly. only thing written on it is SUPER FAMICOM AC/DC 1000mA :/
They both produce exactly the same results, this gradual shifting of odd&even fields from bottom to top of picture.
The SFC specs are 10v-850mA-19VA.
I don't know what 9VA or 19VA is supposed to represent but they're different to start with..
To be totally certain, I have an official HVC-002 on the way that 'ill be using with a 100W quality 220-110volt converter.

Maybe something to consider?

Definitely, thanks for your input 

(If it is the power supply it would explain why you are having the same problem with two different Famcicoms - assuming you were trying them both with the same power supply.)

Unfortunately, 2 SFC and 2 unofficial power adapters tested already 
Let's see if the LM1881 circuit or the official power adapter helps...
Else I'll just use S-Video because I don't see what else will be left to try.
Not investing 200+ bucks in a RGB upscaler just for the SFC either :/
See you!

Alcahest

[Link83]

Deleted this post as I was wrong  - and I dont want to spread incorrect information 

[Alcahest]

Oh I see, well not at all!
The SFC and PAL SNES don't use the same power source at all!!
SFC is DC 10volt 850mA negative center
PAL is AC 9volt 1.2A (i think), positive centre
Totally different and almost certain to kill your SFC!!
See you,

Alcahest

[Link83]

Oh I see, well not at all!
The SFC and PAL SNES don't use the same power source at all!!
SFC is DC 10volt 850mA negative center
PAL is AC 9volt 1.2A (i think), positive centre
Totally different and almost certain to kill your SFC!!
See you,

Alcahest

Really? 
Oh well, sorry! I guess using an Official Super Famicom Power Supply with a stepdown is your best bet then.

I was sure I had read that you could use a Power Supply from your own country with a Super Famicom. I know its definitely fine with the NTSC N64, Gamecube and Wii - as I have mine connected using Official UK power supplies. Good job I never tried it with a Super Famicom then!

Thanks for correcting me, and sorry for almost spreading mis-information 

[Alcahest]

Really? 
Oh well, sorry! I guess getting an Official Super Famicom POwer Suply is your best bet then.

Haha indeed, using PAL adapter would solve the problem once and for all though, dead SFC 

I was sure I had read that you could use a Power Supply from your onw country with a SNES. I know its definintely the casse with the NTSC N64, Gamecube and Wii - as I have mine conncted using Official UK power supplies.

Not for the SFC/PAL SNES :/
What seems to work though is PAL NES adapter for PAL SNES or US NES adapter for US SNES, etc..
See you,

Alcahest

[acem77]

i use a snes on my xrgb2 plus that is conected to my samsung dlp and it works great.

Yep, upscalers are one way round the problem. xrgb2(+) probably cheapest around that's regarded as good PQ.

I had read the xrgb2(+) does not support "weird syncs" of arcade boards or genesis, wheras the older model (non-plus) does. Ideally you'd need someone with the same tv to test with and without....

so far i got xrgb2+ working with everything under the sun for consoles.
nes,snes,n64,duo,tg16,supergrafx,sms,genesis,nomad,cdx,saturn,dreamcast,neo-geo,cdi,jaguar,3do,psx,some of the sytems needed mods but they work.
other systems use the component hook up ps2, xbox, wii. for games that dont support 480p.

i say 80% of the acrcade boards i have work. if they dont those same boards cause hell(mainly midway pcbs) with any other converters i have tried.

I have many systems hooked up so it makes it will worth it.
i bought my xrgb2+ on ebay for $100.

[phreak97]

i used to have a snes that had a funny kink in the horizontal at the top of the screen, turned out to be cos i was using a power cable that wasnt powerful enough. it was also dc, which would have been ok except it was 9v, which ends up as 7.5ish after the rectifier, which is probably marginally ok for the regulator, but i guess it wasnt backed with enough current..  a much worse scenario than what you have, but it's not impossible to affect just a part of the video by having the incorrect power.


VA is volt-amps which is the measure used for transformers. it's volts multiplied by amps, which is the same as watts.. i have no idea why watts arent used.

9V 1A = 9VA, oddly enough though 10V 850mA is 8.5VA however.. not 19VA, i dont know how to explain that.

[NFG]

9V 1A = 9VA, oddly enough though 10V 850mA is 8.5VA however.. not 19VA, i dont know how to explain that.

Bad math? 

9 x 1 = 9
10 x .85 = 8.5

[phreak97]

The SFC specs are 10v-850mA-19VA.

ok, what's actually written on an hvc power adaptor is as follows:

AC100V 50/60Hz 18VA
DC10V 850mA


in this case the 18VA isnt anything to do with the transformer's output (not entirely true, but regardless) it's just the japanese way of saying it's going to draw 180mA from your 100V wall outlet..

the output is 8.5VA, as said before.

on your other adaptor the VA is the output value..

really though, western society doesnt use VA as a measurement for consumer power adaptors, just look at the volts, amps, and if it's ac or dc. ignore va, as you can already see the confusion it's caused.

[Alcahest]

in this case the 18VA isnt anything to do with the transformer's output (not entirely true, but regardless) it's just the japanese way of saying it's going to draw 180mA from your 100V wall outlet..

Thanks for this explanation, finally I know what those "VA" stand for.

i used to have a snes that had a funny kink in the horizontal at the top of the screen, turned out to be cos i was using a power cable that wasnt powerful enough.

Woahhh! 
I *so* hope this is my issue as well and the official adapter helps!
I'll be sure to post as soon as I have tested it 
See you,

Alcahest

[Alcahest]

Today I tested 2 new AC adapters (including the official jpn one) and a new SFC, for a grand total of 4 different power adapters & 3 SFCs, it's getting nuts. 
Anyway, the problem is still there.
It's between my TV and the signal outputted by the SFC for certain.
Last chance is the LM1881 circuit, then I'll have no other choice but fall back to S-video, which looks pretty damn good already (and surprisingly sharp natively).

Another idea would be to analyze the 240p signal outputted by SFC and compare it the one from a PSX but i don't have the knowledge nor tools to do so. 
Later,

Alcahest

[phreak97]

if i had a scart to hd15 (vga) adaptor, i'd try my hdtv.. as mine's fairly low-end.. but i dont, and i dont have the spare parts to make one atm either:(

[Link83]

Found someone else who has recently been having the same/similar problems as you over on NTSC-UK:-
http://ntsc-uk.domino.org/showthread.php?t=88845
No solution though 

[Alcahest]

Link83, thanks a lot for the info.
This is very interesting....!
The person has no problem in PAL 50Hz, but has exactly the same as mine in 60hz...
I'm waiting for my registation there to be approved to post...
My SFCs aren't modded and only do 60hz so I can't try 50, i wouldn't play in 50hz for all the gold in the world even if it worked properly though. 
Later,

Alcahest

edit: gahh it's taking awefully long to get regged there or what?

[marqs]

There's some interesting info on Hardware Hacker from 1992  : http://www.tinaja.com/glib/hackar3.pdf, page 52.1

[Alcahest]

marqs, interesting info too, keep them coming guys! 
Here's the interesting bit:
http://videoff7.free.fr/hackar3_snes.jpg

At the moment, i'm waiting for the sync stripper components to arrive (to build this module: http://www.gamesx.com/misctech/lm1881.htm )

My registration on ntsc-uk is still not complete so i can't post there yet. 
(i wonder what on earth is taking them so long.. this ain't like GAF -3 months- now is it?)
Link83, would you be so kind to link our thread here, on the thread there?
I would really like some infos on the TV model that person is using and other small details..
See you,

Alcahest

[Link83]

My registration on ntsc-uk is still not complete so i can't post there yet. 
(i wonder what on earth is taking them so long.. this ain't like GAF -3 months- now is it?)
Link83, would you be so kind to link our thread here, on the thread there?
I would really like some infos on the TV model that person is using and other small details..
See you,

Alcahest

Hi Alcahest,
I have added a reply on the NTSC-UK thread with some information for them, and linking to this thread as you asked 
I hope you get your registration soon (Mine arrived within a few hours) maybe email the Administrators and ask if theres a problem?

[Alcahest]

Thank you very much Link83 
I'm going to send ntsc-uk mods a message but i'm not holding my breath..
See you,

Alcahest

[Alcahest]

Hey All,
Received the LM1881 and built the circuit (thanks to RGB32E's advices ^^)
http://videoff7.free.fr/lm1.jpg
http://videoff7.free.fr/lm2.jpg

Unfortunately, the flaw is there, exactly identical, there are no changes to the SFC video signal whatsoever.

As viletim was saying "The problem is with the timing of the video signal, not the electrical properties", therefore the LM1881 cannot help, it's beyond its reach.

At this point, I am completely out of ideas. I am using S-Video since it's the 2nd best option.

I still don't understand how S-Video is working just fine and not RGB.. unless my tv is doing some dodgy stuffs on the RGB inputs (Scart). (but then how come PS1 240p RGB works just fine!?)

Anyway, thanks again to everyone who helped, very appreciated 
See you,

Alcahest
edit: ntsc-uk must have banned my host or smthg, impossible to get in touch with them or register there.

[Alcahest]

Finally I was able to post on the ntsc-uk forums , and found a 3rd person with the exact same issue! 
What's most interesting is that he uses a Toshiba LCD hdtv (I use a Sony).

It confirms yet again what viletim said, "The timing of the pulses which tell the TV when to start a new line, new field, etc are a bit off. Nintendo (as well as all the others) allowed this because it reduces complexity and they knew they could get away with it - it worked with all TVs of the period."

So to everyone who's been lazy up to now , if you have a SFC/SNES capable of outputting 60hz, please connect it to your HDTV using RGB scart cable and check for a visual flaw towards the top of the screen.
Again, flaw only shows up with RGB cable and low-res games running at 60hz (99% of them are, just try mario world, f-zero or castle4 ^^)

Later,

Alcahest
Edit: At this point the problem has been confirmed on Sony, Toshiba & Samsung LCD HDTVs.
It is definitely not an issue with my specific TV model for sure. Salvation is in an oscilloscope, which I don't have 

[wedley]

Been reading this post with interest, I'm currently running a switched PAL SNES on a HD Sony LCD TV through a composite cable. Although I don't notice the jagged lines on title screens I have noticed that sprites some times do not display correctly e.g.. F-Zero on some of the tracks the main craft sprite goes all jagged, on other levels it appears ok.

I was hoping to get an RGB Scart cable as the composite isn't all that good, but reading this post I might be better off with a S-VHS cable, which leads to my question does a PAL SNES out put a S-VHS signal?

If anyone knows would be a great help,

Thanks,

Wedders.

[Alcahest]

Hi, I would still try RGB if I were you.
It could be that your TV likes the imperfect SNES 240p 60hz signal... can't really know before you test it.

The problem has been confirmed by only 4 persons so far, including me, statistically this isn't much ^^
(but it may be that we were the only ones with lcd hdtv setups who actually tried snes on it... i think people are rather playing PS3 atm ^^)

If RGB doesn't work however, Svideo is the solution. Frankly after a bit of tweaking the image looks excellent. (on my sony hdtv I reduced Brightness from 50 to 45, raised colors to 58 and reduced sharpness to 10, it looks great!)

So yes to answer your question, PAL SNES are also wired for S-video.

Hope it helps,

Alcahest 

[Alcahest]

Hey all,
A year and 1/2 have already passed since my last message, woah.
I come back with good news and the final word in this mystery:
It turns out the TV scaler was responsible for this issue (as many of you hinted at).

I've since upgraded the TV and was delighted upon connecting the SFC via RGB (GC official EURO RGB Cable) to see a PERFECT picture from bottom to top.
I tried so many things (read up lol), I could hardly believe it  

I must say that while S-Video was a satisfying solution, RGB blows it out of the water when it comes to color precision, more vibrant and clean (as expected).

Some pictures:
The problem was:


Now:


Yaye!


So it looks like the scaler available on early Sony TVs isn't fine tuned for the SFC signal after all and produces the visual flaw. On the more recent TVs with "Bravia Engine 3", I can confirm it's just what it should be, close to perfect PQ.

Thanks again Lawrence, albino, marqs, RGB32E, kyuusaku, Silver, Link83 & phreak97 for your advices and extensive infos on the subject, the case is now resolved; bad scaler is bad.