I have a 1980 Firepower Pinball machine, wouldn't go into attract mode but replaced IC19 RAM and resoldered the 40 PIN connector and everything works great now. There were a few issues with the playfield but mostly contact points. Couple transistors were also missing, but replacing these restored sound.
Only thing not working now is Solenoid 7, for the left shield. The driver board has been played with, not sure why someone would do this, but pin 6 of IC5 has been connected to pin 1 of IC4. Pin 1 of IC4 has been stripped so no longer connected to pin 17 of IC5. Could this be related or why would someone jumper pin6 of IC5 to pin 1 of IC4?
Testing Solenoid 7, it seems when I check the transistor in the diagnostics mode, it never gets a ground and just has a constant voltage, if i ground it the solenoid works fine. For the solenoids that work their transistors get an alternating ground.
Considering replacing the solenoid peripheral integration connector PIA IV (8620), or one of the 7408s chips that control solenoid 7. Not entirely sure if IC2 is the 7408s chip that controls solenoid 7.
HI
ReplyDeleteI would recommend fixing the cut lands and replacing the Transistor. Also be carful to replace cut land on IC4' This will fix the sol 7 issues, The only other important part is to replace the lamp connectors Without this you will wish you had not replaced the parts