Atari Asteroids Deluxe arcade pcb repair
I’d previously replaced all sockets on this PCB and cleaned the ROM legs as both can tend to go bad on Asteroids boards. Now a year or two later, it was making a loud humming sound and constantly resetting. Test mode did run though albeit with bad vectors. However it displayed well enough to print ’2N’ on screen. Indeed the IC at 2N is one of the vector table ROMs and it did seem to be bad as a replacement eprom was fitted and gameplay worked again.
Asteroids like other early games, has separate circuits for each sound effect – the fact they were all out and only a hum could be heard suggested it would be the summing amplifier that combines all the individual sounds. The LM324 at location P11 was replaced and everything was good again (a compatible ‘GM324′ from a DragonNinja bootleg was used as I didn’t have any LM324′s to hand).