Donkey Kong pcb repair

This two stack Donkey Kong pcb had all sounds apart from the music at the how high screen and the background music. A bit of basic research suggested it was most likely caused by bad EPROMS 3H or 3F, the 8035 or LM324 amp. All these were fine so using the schematics I made a note of what else was connected to EPROM 3H (the one that contains the music) the hp comparator flagged all outputs as being bad on the first TTL I checked a 74LS374 @ 4E.

Piggybacking a good 374 brough the music back, I fitted a socket and the new 374 repair complete.