Multi-Wars pcb repair

This board was removed from a Gayton games upright cabinet. They made bootleg cocktail and cabaret cabinets in the early 80s, they're probably best known for their Pacman bootleg 'Munchyman'. They made quite nice cabinets with G07 monitors and mirrored marquees / bezels that you'd expect to see on a pinball machine rather than a video game.

Anyway onto the board this is a bootleg version of Uniwar S by Irem, this hack / bootleg seems to be pretty rare as it's not in mame (see what I did there?) :)

After making up a jamma adapter I was greeted with this

The text was repeated, some missing and repeating sprites no starfield and no explosion sound. After a bit of poking around I found a bad 74LS86 @ 3B. I've found if there's a fujitsu ttl with a cap or wire soldered across the top of it stopping you from easily connecting your test equipment to it you can pretty much guarantee it's bad.

This fixed all the issues except for the missing starfield and explosion sound, looking at the galaxian trouble shooting manuals (as the hardware is similar) suggested these two were related. I wasn't finding the same ttl the galaxian manuals were pointing to though. A big thanks to Macro for pointing me in the right direction, it turned out to be a bad 74LS74 @ 2D.

The strange thing is once I removed it and put it in my abi chipmaster chip tester it passed. I installed a socket and a new chip anyway as I knew it was bad when it was in the board from what I was seeing on the logic probe.

Repair complete.