Modded PS1 stuck in black and white

[Heihachi_73]

First, before anyone bothers with the usual "your PAL TV doesn't support NTSC" or vice versa...

This is a regular Australian market SCPH-7502 PAL console, with a modchip, running on a 2003-era PAL TV (LG Flatron RT-21FA31 CRT) and several LCDs, all of which are dual PAL/NTSC and have no issues whatsoever displaying either signal.

It is not a TV or cable issue (I have four PS1 composite cables which work flawlessly with the other three PS1s and two PS2s I have lying around). FWIW, PAL PS2s output NTSC in 60Hz mode, despite the games saying it's "PAL60" - GameCube/Wii on the other hand do output PAL60, as do modded PAL PS1s running NTSC games.

Right, got that over with...

For around 15 or so years I've had a PAL PlayStation 1 in storage which is virtually unusable, as it outputs everything in black and white regardless of whether it's a PAL or NTSC game or even at the PS logo and in the BIOS itself.

Once in a blue moon it might even randomly flick to color after about 2/5/10/30/60 minutes of being left on, other times it will be B&W no matter what I do (namely, jiggling the AV cable in and out hoping that it does something useful). I was thinking maybe it was a cracked solder joint on the board but can't seem to find any issues (yet). Looking at Google's results it's seemingly a common issue, but no-one has any fixes for it either.

[stj]

Re: Modded PS1 stuck in black and white

page 18

trap filter, L507 & c523 would be a good place to start
and make sure none of the protection diodes are shorted
AND STOP USING GOOGLE!

[Heihachi_73]

Re: Modded PS1 stuck in black and white

Thanks for the schematic.

I had a look at the PS1 today, and as soon as I took it apart a modchip wire fell off before I could even start. Fun.

Turns out that whoever soldered it in 20-odd years ago destroyed the solder pad to pin 5 of IC732 (where said modchip wire is supposed to be connected), ripped up the 0.5mm trace and then soldered the wire directly to what was left the trace in mid air using the smallest amount of solder imaginable, and it's been sitting there loosely for over twenty years waiting to fall off the instant the metal shield was disturbed. Naturally, what was left of the trace ended up becoming a flimsy 3mm extension of the wire.

My only option now is to solder the wire directly to pin 5 and hope the thing doesn't snap off. I have very carefully lifted the leg of pin 5 (didn't seem to be connected to anything else, just the test pad which was obliterated anyway) but it's going to be a pain to solder such a tiny thing as it's much more delicate than a traditional socketed chip.