Donkey Kong pcb repairs

This is actually two different Donkey Kong boards but I'll post them both here. The first worked but had a really nasty sounding jump sound.

Eventually tracked this down to an open capacitor (C24)

 
A low voltage cap with no physical damage, you don't see these going open very often.

That fixed the jump sound.

Now the second board has a high score saving kit which gave a DMA and NMI interrupt BAD at startup and if I continued it was missing sprites.

 

I expected a bad D8257C DMA controller but after replacing it nothing changed, I eventually found a bad 74LS138 @ 1C

 Confirmed bad out of circuit.

 

 Socket and new chip fitted.

 

  

 

Now boots with sprites. That's it for now but I might have to revist this one as I noticed a small area of garbage at the top of the screen while playing.