I’ve been fixing a Genesis for a couple of months that came to me totally wrecked. I’m close to fully operational but having an issue with the soundboard. The board originally did not work but after bench testing it against a good board I have almost all the sounds working.
It is not playing any switch sounds. I’ve been methodically replacing ICs and testing using the schematic but no luck. You can see from the attached picture the ICs I’ve changed because I’ve added sockets. I’ve also tried swapping the ROMs.
Can anyone help me understand which part of the board is responsible for switch hits? My baseline test is using the credit switch to see if a sound is made. With a working soundboard the game makes the add credits sounds. With this soundboard it doesn’t. Is there anyway to determine from the schematic which data line makes this sound?