sdz wrote on 2025-11-24, 20:57:

The RAM ICs, clock buffer IC (next to the RAMDAC) and the VGA mux IC also sit on the 5V rail.
If you don't have a thermal camera, you could try applying some IPA, inject current into the 5V rail, and see where it evaporates first.

RAM was next on my hit list...

Lostdotfish wrote on 2025-11-24, 21:33:

sdz wrote on 2025-11-24, 20:57:

The RAM ICs, clock buffer IC (next to the RAMDAC) and the VGA mux IC also sit on the 5V rail.
If you don't have a thermal camera, you could try applying some IPA, inject current into the 5V rail, and see where it evaporates first.

RAM was next on my hit list...

24 RAM ICs later....

...short is gone.

I took them off in groups of 8 (4 front / 4 rear) starting bottom right. The short was still there until I took the last group of 8 (nearest the SLI connector) off.

So my guess is this card was in a machine that had a PSU fail and dumped too much voltage through the 5v PCI rail. It burned out the FB10 and Cap in parallel but also burned through the RAM ICs at the same time.

I'll test these chips and get replacements and put this card back together.

If there was 12mb,You can solder only those rams that are good and make 8mb card, untill replacements arrive.

butjer1010 wrote on 2025-11-25, 11:04:

If there was 12mb,You can solder only those rams that are good and make 8mb card, untill replacements arrive.

Nope they are all toast. I'm getting very low resistance to ground on all 24 chips...

In other news, this is progress...

I put the DAC back on and moved all the caps etc that I'd taken out of circuit back in place. This is the board with no RAM ICs installed at all. Before, MOJO would just hang. So I think if I can get a set of good RAM, we'll be off to the races.

Yeeeey, hope this will be the only thing to change

butjer1010 wrote on 2025-11-25, 14:10:

Yeeeey, hope this will be the only thing to change

BuB had a very similar failure mode card on his Youtube channel... the FBI ended up needing to be changed as well. Hoping mine got away with it....

I've ordered some RAM from Aliexpress, so I'll revisit this in a week or two when they arrive.

butjer1010 wrote on 2025-11-24, 13:42:

https://www.youtube.com/watch?v=4oZlt9Dl43I

Thank you for posting this. Hitting components with freeze spray to troubleshoot is pretty common - I found it interesting to see that in some circumstances, doing the opposite might actually be helpful also.

Lostdotfish wrote on 2025-11-25, 14:31:

butjer1010 wrote on 2025-11-25, 14:10:

Yeeeey, hope this will be the only thing to change

BuB had a very similar failure mode card on his Youtube channel... the FBI ended up needing to be changed as well. Hoping mine got away with it....

I've ordered some RAM from Aliexpress, so I'll revisit this in a week or two when they arrive.

I hope it is ok, when mojo shows it.... we'll wait for update!

elszgensa wrote on 2025-11-25, 18:08:

butjer1010 wrote on 2025-11-24, 13:42:

https://www.youtube.com/watch?v=4oZlt9Dl43I

Thank you for posting this. Hitting components with freeze spray to troubleshoot is pretty common - I found it interesting to see that in some circumstances, doing the opposite might actually be helpful also.

Yep, great video, i was enjoy to watch it, now i'm waiting next faulty voodoo to try that method 😀