Mortal Kombat 2 - Graphics Issues, resets even through tests are all good

[callanbrown]

Hello folks,

Working on this Mortal Kombat II board. It passes all startup tests consistently. There are errors with all sorts of backgrounds and text. Some screens with no motion are perfect. I've tried swapping the socketed customs with known working ones, no change there.

The board eventually resets at predictable points leading me to think the problem must be more on the CPU side. Anyone seen something like this before?

 

[mecha]

do you know what the Williams Custom Chip is? it's the quad flat pack surface mount one in the middle of the board. try putting light pressure on it in a 2 player game and see if that affects the graphics at all.

 

[callanbrown]

Thanks for replying mecha,

I did inspect UE13 under the microscope to check for popped pins and even reflowed a few but it made no difference.

However I gave the bottom of the board a good ol' inspect and found a pin near the CPU bent over and touching another. Cleared that and we're back in business.

Board fixed!

 

[mecha]

Thanks for replying mecha,

I did inspect UE13 under the microscope to check for popped pins and even reflowed a few but it made no difference.

However I gave the bottom of the board a good ol' inspect and found a pin near the CPU bent over and touching another. Cleared that and we're back in business.

Board fixed!

yeah those component legs are long and bendy and can cause a lot of issues if you're reseating roms or something on a hard surface. I'm uncertain why people took the plastic feet off those to begin with. lol