Twist, remove and then replace the bulb into the socket to see if the bulb will light.Then create columns for connector/pin, transistor number, bulb, socket, wiring, connector, pins, transistor, decoder, MPU signal. Create a table and in the far left column write down all of the non-working lamps. This should cause all of the MPU controlled switched lamps to blink on and off. Start by putting the game into the lamp test mode by pushing the red button on the front door one time.Bad connector on MPU J1:11-19 (this is where the signals for the lamps are sent to the lamp board).This is where the logic signals enter the lamp board from the MPU board. Bad connector J4:4-11, 13-17 on lamp board.Bad wire from the light board to the lamp.Remember, you might have multiple issues with a lamp especially on older games or ones that have been in storage for a while. Here is a basic list of what could be wrong. The transistor grounds the circuit and turns the lamp on.A decoder chip on the lamp board processes these signals and sends signals to the appropriate transistors.Signals from the MPU board are sent to the lamp board (MPU J1:11-19 to Lamp J4:4-11, 13-17).Each lamp has a discreet wire that goes from the lamp to the lamp board.Transformer through fuse F1 (10 amp on pre-Xenon and 20 amp post-Xenon) to bridge rectifier (BR1) which converts this to 5.4 vdc which goes to the playfield. Power (6 vdc) comes to the playfield from the Power board (Fuse F1 and bridge BR1) via the bare ground wire that goes from lamp to lamp.This is just a comprehensive way to track down lamp issues.

So, I fix it by doing the following.Īgain, use only the steps that you actually need. Used in a while the lamps can have multiple issues causing them not to work.

I’ve found that on an old game that hasn’t been This is what I do when I get an old game that has several non-working lamps. Note that you probably won’t need to do all of these steps.

After that, I will give some miscellaneous notes. Rather, each lamp is a discreet circuit so it is fairly easy to figure out what is wrong.īelow will give you a list of what could be wrong and then the steps for diagnosing each of the possible problems. They did not use a lamp matrix like Williams. Bally lamp issues are USUALLY pretty straight forward and easy to diagnose and fix because of how their lamps work. Below is a step-by-step process for fixing non-working lamps on a Bally game.

Bally pinball repair