Just got a Hollywood Heat in unknown functional condition. Checked fuses and found several blown before power up. Replaced them and game started and played without sound but would randomly reset. Reseated all connectors and performed ground mods. Played a few games and sound was restored. Several power cycles later, random resets persisted and sounds come and go. Determined the power supply was the cause of the resets, the slightest movement of either connector would cause resets. Tried reflowing solder joints without success so I replaced the supply and the game stabilized.

Game is fully functional and playable but no music so I’m assuming the resets damaged something on the sound board. Game/switch sounds are present but no music and LED is solid and not blinking. Replaced 6502 (known-good) at T3 and still have the same results. Installed a MA-766 from another game and everything worked so it’s definitely a board problem. I’ve owned just about every Sys80b and have been fortunate enough to have never had a sound problem until now so I’m a little lost on where to go next in working through this problem.

Shooting in the dark on next steps so any help is appreciated.