PGM mother board repair log

[XeD]

So I had a converted Espgaluda and motherboard that was giving me this Error. Not familiar with the PGM I clean all connection and looked for broken traces. This did not improve the picture. The odd thing is this issue is only on the espgalude cart on that motherboard (at least from what I can tell from my small test bench) So I got myself the Cave converted set for my personal collection. Swapping parts around I narrow the issue to the main motherboard. Turning down the voltage to 4.9 made it worst and up to 5.15 was a little better.

I did some more research. There doesn't seem much on the PGM some post said to check the work ram? I changed out the 2 SRM2B256LMX55 located top right with the dipswitch the the top right. On my board it's U30 and U28 on other revision it's U27 and U28.

I didn't feel like waiting for parts, so I went to my parts bin and salvage some from a neo geo board. The PGM use faster ram 55ns. The 100ns seem to work for now. The 120ns on the other did not.

 

[PascalP]

Nice you got it running again!

Any idea what this might be?
Cart works fine in another motherboard;

 

[nam9]

Here's my contribution!



Thoughts?

 

[XeD]

When I has swaping rams around I had similar issues. @PascalP I had this when I did not solder a leg. @nam9 I had similar error code (don't recall what it was but similar layout) when I solder in the 120ns. This was when I notice the timing on the original. Good thing 100ns work as that was all I had. Now I'm a novice at best, but I would say try those 2 rams and see what happen. From the few post I read those ram seem to go bad. Most likely from to high a 5V.

 

[PascalP]

nice, gonna try pushing them down first, see if that helps!
So to be clear these are the rams you mention?

 

[XeD]

nice, gonna try pushing them down first, see if that helps!
So to be clear these are the rams you mention?

Yes. In that orientation it's the 2 on the left