Bank Panic repair

I've had this board for years, I got it when I cleared out a local operator. I always thought it was a puzzle game for some reason but after watching game play of it on youtube I finally decided to dig it out and make yet another jamma adaptor.

The label maker ran out of tape. :(

When powered up I was greeted with a black screen and no sound. Checking the cpu (Z80) with a logic probe I could see the reset circuit was working as it should but there was no clock, it was stuck high instead of pulsing.

Looking at the crystal it looked fine, and not snapped off as I often find them. Looking slightly above the crystal I see a Fujitsu 74LS74.

The comparator flagged pins 5 and 6 (outputs) as bad.

Piggybacked a good 74LS74 on top.

and it fired right up.

Unfortunately after about five minutes of playing the game, it crashed and reset then refused to work at all.

Looking over the board again I spot more Fujitsu.

 Another 74LS74 and again it flags the same two outputs.

I was going to replace all the Fujitsu anyway, it's like they knew and committed suicide as I found two more bad 74LS74s.

All Fujitsu removed and replaced.

The board is back to working.

The sound was a bit scratchy and quiet but after replacing the 3x 220uf 16v caps in the bottom right corner of the board the repair was complete.

The game is surprisingly fun and addictive, defiantly one for the collection.