I picked up a Jokerz project. I had the CPU and sound boards repaired. The game now boots up and plays, sort of. It starts out with sound and speech working but two of the pops, both slings, and some switched don't work. After playing for a few minutes, the pops, slings, and switches work but not the speech. After more play, the pops, slings, and switches don't work and the GI goes out. What can cause the variations in failures and any thoughts on how to fix it?