Resolder the transformer terminals and then replace all the caps for a 99% guaranteed repair. The biggest failure is the electrolytic caps go bad from the heat of the board being mounted on the cranes ceiling. You failed to mention if anything was wrong with this board but I am assuming you havent had it hooked up. You mentioned 60 volt bulbs.If your crane has 60 volt bulbs, they are wired in series in pairs to create a 120 circuit. The 110 AC common is visible if you turn the board over and look at the traces at the connector pins. The outputs from the fuses go to the connector pins then to the AC HOT of each of your chase light strings. The 110 AC in goes from the connector pins to the transformer. The chips generate a chase pattern that controls the TRIACs mounted to the aluminum heat sinks. In this case the board has 4 chase outputs of 110 volts AC. There is a pot in front of the transformer for the chase speed adjust. There is a zener diode to drop that voltage to near +5 volts dc for the ICs to use.Īnyways the circuitry for the chasing is 5 volts. The transformer drops 110v to possibly 12 volts. Yours appears to be the 4 circuit version (the number of TRIACS on the heatsink). There is a version of this board that has 4 chase circuits and a version that has 3 chase circuits. I have worked on literally hundreds of crane machines.
