March 01, 2021, 08:59:48 PM

SNES 1chip mobo 50/60 hz mod

Started by malebolgia, June 24, 2005, 04:05:44 AM

Previous topic - Next topic


I'm wondering if it's possible to add a 50/60 hz switch to an old model snes from 1995 that has a newer motherboard (the snsp-cpu-1chip-02 to be precise)? It doesn't have the ppu-1 and ppu-2 chips the older models have. I've done mods on older models but not this one. I heard it might be impossible... please help me out if anyone has any suggestions...

The Netherlands


Thanks a lot, but the links to the pictures seem to be dead... Also I don't seem to understand a lot of Markus' English... Any techies who DO know what he's on about? Is anyone able to 'translate' for me?

thanks again,



June 25, 2005, 01:45:06 AM #3 Last Edit: June 25, 2005, 01:46:27 AM by Yod@
I found one of the pics on my hard drive.


You are the man!

But since I don't have a background in electronics (I usually follow the steps described on websites) I have no idea what that XTAL stuff means...

shame on me.....


June 25, 2005, 06:15:08 AM #5 Last Edit: June 25, 2005, 08:44:29 PM by Yod@
Fortunately it's not that complicated.
He's drawn the diagram with two switches in order to show what's happening, but you should actually be using a single DPDT switch (double-pole, double-throw - two rows of 3 pins).

One one side of the switch, you're switching pin 111 of the chip between either Ground or 5 Volts. So you need to carefully lift pin 111 of the chip up, then solder a wire from that to the middle of one side of the DPDT switch. You should wire Ground and 5 Volts to each of the other pins on that side of the switch.

On the other side of the switch, you're switching between two different timing crystals - one rated at 17.734476 MHz for PAL (and should be connected to the same end of the switch as the 5 Volt wire on the other side), the other crystal is 21.47727 MHz and is connected to the same end as the Ground connection.
There'll already be an existing crystal on the board (the frequency of the crystal will depend on whether you've got a PAL board or an NTSC one), so you're going to have to remove the crystal, and then wire up the circuit as shown in the diagram.

The 2.2k resistor is just for safety reasons - if the 5 Volts get shorted out somewhere, the resistor will help prevent it from frying something.

Hope that makes sense, apologies if any of that insults your intelligence! :)
EDIT: Fixed a couple of typos. 12 Volts indeed.  :rolleyes: I suggest you read through again to make sure you've seen the correct and now coherent version of the instructions.


That DOES make sense! Thank you so much. I'll try as soon as I get my hands on that SNES again (it was a present for a friend of mine and I was supposed to have it modded by the time I gave it to him... obviously that didn't go as planned)

Again, you are the man!

If I get stuck, I'll post some more questions and just count on you to help me out again..  ;)


Oh yeah, and I suppose I'll need to get a hold of an NTSC crystal then? Mine is PAL...


yeah, you do, but theres a chance your local electronics store will either have it or be able to order it for you. the crystals arent exclusive to the snes, crystals are used in loads of things. just write down the value of the crystal and take it in.


thanks a lot!
I'll go try and get one...


June 12, 2008, 12:23:47 PM #10 Last Edit: June 12, 2008, 12:56:01 PM by baconbeastnz
mmm i know this post is 3 years old but here goes...

the one thing i dont understand from these instruction is concerning the first switch.

we connect PIN 111 to the middle. But how do we set one end of the switch to ground and the other to +5. Does that switch do that automatically? or do I have to connect each end to something else which gives off 5V for example...


November 28, 2013, 07:09:33 PM #11 Last Edit: February 26, 2014, 08:43:16 PM by Shadow_Zero
@baconbeastnz: check out mmmonkey's guide:

So is this mod 100% working?

Got a 1CHIP PAL SNES now, so modding it is on my to do list for the future  ;)
And btw, kudos for Moosmann for figuring this out and Yod@ for replying in here!  ;)

Also an interesting thread:


Does still have the 21,47727 MHz crystal oscillator?


Quote from: Shadow_Zero on November 28, 2013, 07:09:33 PM
So is this mod 100% working?

yes it is working, but you will lose color on composite on 60hz, use a rgb cable, a gamecube one will be perfect.

It is also possible to  wire a lifted pin on video encoder to fix 60hz color. In this way you will have a standard pal composite on 50hz and e standard ntsc composite on 60hz.


Yeah, I was trying to figure that out. Read mention about lifting pin 9 of the S RGB chip (
Where does it wire to?

Is it true that PAL60 won't be in color when using composite/s-video, or does it depend on the tv? (PAL60 with Gamecube for example works, right?)


let's lift pin 9, solder a wire to a switch and supply 5v when you are in 50hz and gnd when you are in 60hz. Of course you can use just a 3 way switch for 50/60hz and put all wires (video encoder, big chip pin 111 and the two crystal).

For gamecube or 2ppu snes the color subcarrier is ever pal .

In the 1-chip snes you are switching between pal and ntsc cristal, so different frequency, passing trought the big chip, will reach the video encoder, setting 5v or gnd to on pin 9 you will inform the video encoder about that. It will encoder the right composite signal


February 19, 2014, 11:58:45 PM #16 Last Edit: February 20, 2014, 12:01:21 AM by Shadow_Zero
So I have an 2 ppu SNES which switches fine with either composite, s-video and RGB. That's PAL60 then, right?
So should I give the 1CHIP SNES S-RGB pin 9 any attention then? Cause now I assume PAL60 should work fine for me.

But let's say I want to lift and solder it to the switch, why a 3 way switch and not a 2 way switch? (I just switch between 50 and 60hz, not?)

I reckon I might not get your last line fully, but perhaps that already answers (part) of my question. But then I need to read back how the mod on the old revision exactly goes and compare it to the 1CHIP mod.


You need to lift pin 9 of the video encoder only in 1-chip board.

for 3 ways i was meaning 3 different and isolated "rail".

anyway I checked again, you just need to solder a extra wire in same point on the 2way switch of the pin 111'swire. So a DPDT switch is what you need


February 20, 2014, 06:40:49 PM #18 Last Edit: February 20, 2014, 06:58:49 PM by Shadow_Zero
Ah yes, that was going to be my next question, if I could also solder it to the middle contact of the switch where pin 111 goes (or the crystal, of the other row), or needed a TPDP switch (I assume that's the acronym of Triple Pole Double Throw).
That doesn't cause any conflict?

Made a small summary for myself;
Double PPU SNES:
QuoteLockout switch (SPDT):
- one side gnd
- one side 5v + 2.2K Ohm
- middle = leg 4 of lockout chip

50/60hz switch (SPDT):
- one side gnd (link with small wire from other switch)
- one side 5v (link with 2.2K Ohm resistor from other switch)
- middle = leg 24 PPU1 + leg 30 PPU2

QuoteLockout switch (SPDT):
- one side gnd
- one side 5v + 2.2K Ohm
- middle = leg 4 of lockout chip

50/60hz switch (DPDT):
Row 1:
- one side gnd (link with small wire from other switch)
- one side 5v (link with 2.2K Ohm resistor from other switch)
- middle = pin 111

Row 2:
- one side gnd + NTSC crystal
- other side 5v + PAL crystal
- middle = original crystal contact
I take it I solder a 'bridge' to connect the GND and 5v to the other row?

And I'm still not entirely sure how to solder the crystals though, also looking at the Playoffline pics;


look at the attachment


Tx for the drawing!
I assume I can also use 5v and GND as in the MMMonkey guide:

And pin 9 of the S-RGB chip can be soldered to either the middle of the crystal side or pin 111 side?

So one side of the crystals are soldered together, and then go to the original contact.
I understood it doesn't matter which contact of the original crystal contacts you take for the switch. correct? (and then the other for the crystals connection)


Quote from: Shadow_Zero on February 23, 2014, 06:34:34 AM

1) I assume I can also use 5v and GND as in the MMMonkey guide:

2) And pin 9 of the S-RGB chip can be soldered to either the middle of the crystal side or pin 111 side?

3) I understood it doesn't matter which contact of the original crystal contacts you take for the switch. correct?

1) of course!

2) i'm pretty sure of that, Let's try, if you got problem on 50hz mode you will use a 3 ways switch. But i think that will be no need on that.

3) yes, crystals has no polarity


February 28, 2014, 01:37:28 AM #22 Last Edit: February 28, 2014, 01:40:07 AM by Shadow_Zero
Are the crystals purely needed for composite/s-video, or also for RGB output?

Started with the mod, but I'm struggling to desolder the crystal. Need to look into that.


The crystal are needed not only for encoding composite/s-video but also for clocking the Cpu/Gpu.

So absolutely you have to do that job.

Desoldering the crystal is very easy, just warn the two pins of bottom side and use a sucking pump...


February 28, 2014, 01:24:30 PM #24 Last Edit: April 21, 2014, 04:02:55 AM by Shadow_Zero
Well, I succeeded in getting the crystal off, but it wasn't a walk in the park! I used desolder, sucking pump, pressing my soldering iron hard against the hole, somehow it didn't get off easily (seemed to be glued to the pcb as well). Especially the last part was pretty hard to get at, there was more solder than I expected. I hope I didn't damage the pcb...

Ok, modded my first 1CHIP SNES (and my second SNES altogether ;) ). There are some funny/odd things. I hooked it up with composite, s-video and RGB to my CRT tv and my Bravia 3D LED and made some photos:
I guess ikari_01 is right about PAL-M not being supported by many tv's, though I'd like to test it on my Philips CRT in the bedroom, since that one swallowed everything I've thrown at so far. But some facts from my testing:
- RGB is ok everywhere
- composite and s-video don't show proper colors in 60hz (PAL-M)
- odd thing is that my CRT tv produced 'some color', like my LED, the first time I tested it and the second time it just showed black & white. Can anyone clarify that?
- on my CRT tv I had issues with the SNES resetting itself. This was not the case on my LED. Perhaps a dodgy PSU? (they're all officials though, if anyone has some ideas...)

Guess I'll try to hook up pin 9 of the S-RGB chip and see how true NTSC is faring in composite and s-video.


March 03, 2014, 12:33:38 AM #25 Last Edit: March 03, 2014, 06:13:48 AM by Shadow_Zero
Quote from: unshe on February 23, 2014, 01:13:35 PM
Quote from: Shadow_Zero on February 23, 2014, 06:34:34 AM
2) And pin 9 of the S-RGB chip can be soldered to either the middle of the crystal side or pin 111 side?
2) i'm pretty sure of that, Let's try, if you got problem on 50hz mode you will use a 3 ways switch. But i think that will be no need on that.
Tried it, but got black/white screen. After reading some more, especially a post from Ziggy587 on NESDEV:
QuoteSo looking at the encoder in my PAL SNES, pin 9 is connected to pin 11. They are both ground. I took a look at the encoder inside my NTSC SNES mini, pin 9 is 5v. So I'm assuming that all I have to do is lift pin 9 in my PAL SNES and connect it to 5v and all will be good.
I guess that makes sense, since for 50hz 5v is needed and 60hz GND, and for PAL subcarrier GND is needed and for NTSC subcarrier 5v, so that's a cross, so to speak. Luckily I used a DTTP switch so I used the open row to connect pin 9 of the S-RGB chip and the 5v and GND accordingly.

Additionally, my Philips tv in the bedroom actually DID support PAL-M! So bonus points for Philips, and minus points for JVC and Sony   ;)
Although for some reason my Philips didn't like the switch when the SNES was running (I would lose audio/video and needed to restart my SNES...)


Sorry, i was in error:


Pin 111 of S-CPUN --- 5v
Pin 9 of video encoder --- GND

Pin 111 of S-CPUN --- GND
Pin 9 of video encoder --- 5v

use a 3 ways switch


March 07, 2014, 09:45:52 AM #28 Last Edit: March 07, 2014, 07:50:26 PM by Shadow_Zero
Unfortunately my second 1CHIP SNES I've modded has heavily graphic gitches  :(

Anyone any ideas where I have to look into?

Btw, this is for both composite and RGB output.


I feel bad for you Shadow_Zero. There is always an issues with your mods.  :'( Maybe the green wire? (Looks like there is not much solder to it) Something bridging? Have you checked all points with multi meter?


March 07, 2014, 06:43:52 PM #30 Last Edit: March 08, 2014, 03:02:08 AM by Shadow_Zero
lol, 'always' sounds a bit dramatic. We're talking about 1 DENC N64 and 1 1CHIP SNES   ;)
I actually already considered the green wire and added some more solder, but to no avail. I'll try to check things with a multimeter.

But in general, could these graphic glitches be because of a bad connection or defect part? Or must I fear something really broke from the SNES pcb?

Checked everything with a multimeter, no issues there. Soldered a crystal directly on the original position again, but no effect either.

Hooked up 5v directly to pin 111 and tried both a PAL and NTSC crystal on the original spot; still the same issue.
Trying to clean the cartridge slot.


Sorry bro, didn't mean to like offend you.  :-[ It is just that's those are pretty much the only topics i have read from you  ;) If you checked eveything and it makes connection maybe there is a component failure. Did it work flawless before? 


No offence taken   ;)
Cleaning the cartridge slot didn't have any effect.
I soldered both 5v directly to pin 111 with the PAL crystal in the original spot and ground directly to pin 111 with the NTSC crystal, still the same issue. I even tried it without pin 111 connected, but then the image is even more garbled, and the system crashes after a little while.
I'm really beginning to think this SNES has died on me   :(


I personally have had almost no luck repairing super nintendo's. 1 time i got lucky replacing the fuse and another time i got 50/60Hz mod failure that i cleaned up from solder splatter.

Usually when they fail there is:

- Chips failure.
- Bad traces.
- Main fuse. (Rarley if you ask me. Seems to be more common to others.)

I am pretty sure this one is chip failure. But on the other hand it looks like it worked for a split second in the video?

Component failure?


August 13, 2014, 10:14:33 AM #34 Last Edit: August 13, 2014, 10:46:49 AM by Ramis
Thanks to all people who have contributed to this thread. It was very helpful when doing my own PAL 1Chip 50/60 Hz Region Free mod.

I have documented my mod with a lot of photos with comments, I'm sure that it will be very helpful for other people who attemps to mod this thing. If the links go dead sometime in the future, send me a PM and I'll fix the links:

Shopping list:
SPDT (Single Pole-Double Throw) ON-ON switch (used for the CIC/Region chip disabling, you can use DPDT switch instead if thats what you have, leaving one row empty, thats what I went for)
3PDT (Triple Pole-Double Throw) ON-ON switch (used for switching between 50/60Hz, it needs to be at least 3 separate poles/lanes/circuits in order to also switch pin 9 on the S-RGB chip for correct composite video. if you are going for only RGB output, i think you could skip pin 9, in that case you will only need a DPDT switch)
21.47727 MHz Crystal Oscillator HC-49S (NTSC crystal, i bought a few of these on ebay from a chinese seller for a few bucks, some people have free shipping)
2.2k resistor
Multi-stranded copper wire (for the ground/5v wires)
Fine single-core wire (for the pin soldering, I always go with "Kynar cable")

The circuit diagrams in this thread works well (I went with unshe's attached diagram above), even though none of them include pin 9 of the S-RGB chip (which is required in order to get color when running NTSC on composite output, as mentioned earlier). To clarify a bit, you will need to DESOLDER the crystal oscillator on the motherboard, putting it on the switch instead, so that you can alternate between PAL/NTSC crystals.

Important note to other people having problems after modding: When I had first completed the mod and put everything together, nothing worked. No picture, no power light, nothing. It turned out I had made a mistake and cut the ground cable with a screw, frying the 1.5A fuse inside the SNES (this can also happen if you do the mod WITHOUT discharging the snes, turning it one while power is disconnected, the power LED will flash). Luckily the fuse could easily be replaced by mounting normal fuse connectors in its place, and putting in a normal glass fuse so that the fuse can be replaced without soldering in the future (se photos), if you can find a pico/micro-fuse, you can go with that. I could not find a 1.5A fuse in my local electronic store, so I went for a 1.6A fuse instead. If you are feeling adventurous and/or cheap (or just want to test if the fuse is the problem), I guess you could bypass the fuse with a short cable, connecting/shorting both ends of the fuse pads. Here is the guide for replacing the fuse I went with:


Note that crystals are highly sensitive to long wires. It must be soldered directly to the board, with minimal leg length.

SNES consoles with garbled video cannot be repaired in any way. Just discard and move on to the next system.


Hey guys,

I have a new issue. I modded my second SNES, just like I did the previous one. The issue is that when I connect the CIC's fourth pin to the ground, the console won't boot, there's no power. Also, when the pin is simply lifted, foreign games won't start as well. When it's fed with 5 volts, it works as usual.

Does anyone know why the console wouldn't boot when that pin is connected to the ground? It's a strange issue, I've spent many hours on this and soldered/unsoldered nearly everything many times to no avail.


July 07, 2020, 08:43:06 AM #37 Last Edit: July 07, 2020, 09:03:28 AM by Shadow_Zero
Quote from: People? on May 10, 2015, 08:23:00 PMNote that crystals are highly sensitive to long wires. It must be soldered directly to the board, with minimal leg length.

SNES consoles with garbled video cannot be repaired in any way. Just discard and move on to the next system.
Are there ideas for the root cause of such garbled video issues? (just curious)

PS: really annoying Photobucket has blocked image hosting (and keeps spamming to upgrade to a paid account)
Or maybe I'm too much of a cheapskate  :P

Got it on Imgur now: