Location: Littleton, CO
Symptoms: Sound problems, ferris wheel getting stuck, backboard spinner not working, backboard and playfield G.I. lights not working.
One of the ferris wheels was binding causing the belt to slip. I loosened the belt from below and spun both wheels. One turned freely, the other did not. I removed the e-clip, a washer and cleaned the shaft of sticky lubrication. The problem seemed to be the washer, which was too thick and causing to much friction when the e-clip was on. I also noticed that the other wheel didn’t have washer, so I left it off.
The sound kept cutting in and out after the machine warmed up. It would be on for a half-second, off for a half-second, repeat. I pulled out my oscilloscope and checked the inputs to the amplifier. The input signal looked fine. I disconnected the speaker and bypassed the digital volume control just to make sure the problem was with the amp IC. It seemed it was definitely the amplifier IC.
The backboard spinner wasn’t working. It seemed like it was jammed. I took the motor off of the back and shot some lubricant into the gear box. That seemed to get it working again. For how long, I don’t know. The owner declined to replace the motor and gearbox assembly.
The playfield lighting problems were related to a burnt connector, which I see all of the time. I replaced both the PCB connector and the wire connector and the lighting is now working great.
I took the sound board back with me since I didn’t have an amplifier IC with me. A few days later, I shipped the repaired board back to the owner, who installed it and said it’s working perfectly!