Memory test error (008004A8) on PGM Board

[NightShadowPT]

Hi Again,

Seems like I'm monopolizing the board, but either I'm incredibly unlucky, or this is a lot more work than I was expecting.

Some of you may already have seen that I have a PGM board (rev14) that does not boot, and 2 games (Ketsui and Demon Front) that either showing graphical corruption or not booting at all.
Note: I'm running these games on a secondary PGM board that seems to be working well with lots of games (8 to be exact)

As part of the troubleshooting for those games, I've been asked to run the default Hardware tests on my board, and, Lo and behold, there seems to be a problem when testing one of the Ram modules (kindly refer to attached image).

Now I have a few questions:
- How can I troubleshoot this further?
- Is it possible that this is what is causing me trouble with Ketsui and Demon Front (even if 8 other games seem to work without any problems)?

Thank you in advance for any guidance you may provide.

Cheers,

 

[Apocalypse]

Seems like I'm monopolizing the board, but either I'm incredibly unlucky, or this is a lot more work than I was expecting.

No don't worry, it's called collecting arcade PCBs.

- Is it possible that this is what is causing me trouble with Ketsui and Demon Front (even if 8 other games seem to work without any problems)?

Yes it is. Probably the other games doesn't use that part of the RAM (wouldn't be suprising assuming RAM 4 is the higher one).
As often could be the RAM chip, bad traces, or any chip connected to/handling the busses.
I'd probe the RAM first.

 

[ekorz]

Fwiw next time you need PGM stuff shoot @sheep_nova a message and ditch that aliexpress seller

 

[Fluffy]

gc8tech has some repair info: http://igspgm.com/

 

[ic3b4ll]

Hello, I'm the guy who replied to you on FB. I think.
Anyways... What kind of power supply are you using? Are you using a Supergun? Did you check the voltage at the JAMMA edge with the board on? With a proper multimeter?
Can we get some pictures of the actual PGM PCB? The top side please, you'll have to disassemble it but it's easy I promise.

 

[NightShadowPT]

Hello, I'm the guy who replied to you on FB. I think.
Anyways... What kind of power supply are you using? Are you using a Supergun? Did you check the voltage at the JAMMA edge with the board on? With a proper multimeter?
Can we get some pictures of the actual PGM PCB? The top side please, you'll have to disassemble it but it's easy I promise.

Hi,

Thanks for your help, much appreciated.

Regarding your questions:
1 - I am using a Supergun (it is working correctly with a PGM2 board, an MVS and two Atomiswaves) - I'm assuming that is not the problem
2 - I did check the voltage with a Multimeter, it's spot on with the digital indicator on the Supergun (somewhere between 5 - 5.15v depending on how I configure it)
3 - On the topic of pictures of the board, your wish is my command - Please see attached photos. Let me know if you need me to Zoom in anywhere

Fwiw next time you need PGM stuff shoot @sheep_nova a message and ditch that aliexpress seller

Just contacted him, thanks!

 

[ic3b4ll]

The 4 RAM chips next to the dipswitch look like they have some dodgy soldering... Seems like an old rework. The dark grey is usually a sign of cold solder joints (repair rule #275 guys!)
If you know how to do it you can try to resolder them. Use fresh solder if you don't have flux. Make sure you don't bridge any pins and tell us how it goes.

Good luck!