Hello!
First post here and hoping for some guidance troubleshooting and fixing a problem with my Pinbot machine. The current symptom is no sound, speech, or music are heard during game play or when running the built in sound and music tests. I've owned this game for over 15 years and it has always been fully functional. The problem started after a PS issue when the voltage regulator went bad, causing an overvoltage of +12 VDC on the +5 V circuit. After repairing the PS (replaced the MC1723C with a UA723CN, the 2N6057 Darlington, and a few questionable caps) and confirming all voltages OK, the game did boot and go into attract mode with no sound. Pressing the Sound Diagnostic Switch (SW1) indicated one tone suspecting U23 (16k SRAM) which was further supported by this chip being hot, so replaced this with a new 6116 chip. Also found that U4 (Sound ROM 1) on the sound board was hot and its filter capacitor blown so replaced these as well as all other sound / game ROM chips out of concern that my other original ROMs (prototype 5) would not be compatible with the new U4 which is at revision L-1. Will note here that I also installed a sound ROM at U19 which was not originally populated so at present all sound/speech ROMS are at rev. L-1 and game ROMs at L-5. Unfortunately none of this solved the problem. The game still boots into attract mode, a single "bong" is heard, and other than sound all game play (solenoids, targets, ramps, illumination, etc.) are working normally.
Beyond basic troubleshooting and in effort to do more in-depth diagnostics, following this article https://pinrepair.com/sys11_dead/index3.htm#sound I started tracing signals through the sound circuitry on the main board. Note that I do not have the Leon sound test EPROM installed but with the built in sound test running, I checked the inputs at sound PIA U9 pins 2 - 9, as well as the selection signal at pin 23 with an oscilloscope and saw pulsing, however nothing on the output pins 10 - 17 so suspected bad U9 and replaced. Still having the problem.
At this point I don't want to keep throwing parts at it and looking for any guidance on where to go from here.
Thanks!
First post here and hoping for some guidance troubleshooting and fixing a problem with my Pinbot machine. The current symptom is no sound, speech, or music are heard during game play or when running the built in sound and music tests. I've owned this game for over 15 years and it has always been fully functional. The problem started after a PS issue when the voltage regulator went bad, causing an overvoltage of +12 VDC on the +5 V circuit. After repairing the PS (replaced the MC1723C with a UA723CN, the 2N6057 Darlington, and a few questionable caps) and confirming all voltages OK, the game did boot and go into attract mode with no sound. Pressing the Sound Diagnostic Switch (SW1) indicated one tone suspecting U23 (16k SRAM) which was further supported by this chip being hot, so replaced this with a new 6116 chip. Also found that U4 (Sound ROM 1) on the sound board was hot and its filter capacitor blown so replaced these as well as all other sound / game ROM chips out of concern that my other original ROMs (prototype 5) would not be compatible with the new U4 which is at revision L-1. Will note here that I also installed a sound ROM at U19 which was not originally populated so at present all sound/speech ROMS are at rev. L-1 and game ROMs at L-5. Unfortunately none of this solved the problem. The game still boots into attract mode, a single "bong" is heard, and other than sound all game play (solenoids, targets, ramps, illumination, etc.) are working normally.
Beyond basic troubleshooting and in effort to do more in-depth diagnostics, following this article https://pinrepair.com/sys11_dead/index3.htm#sound I started tracing signals through the sound circuitry on the main board. Note that I do not have the Leon sound test EPROM installed but with the built in sound test running, I checked the inputs at sound PIA U9 pins 2 - 9, as well as the selection signal at pin 23 with an oscilloscope and saw pulsing, however nothing on the output pins 10 - 17 so suspected bad U9 and replaced. Still having the problem.
At this point I don't want to keep throwing parts at it and looking for any guidance on where to go from here.
Thanks!