Using a logic probe and schematics to diagnose a light matrix problem

Work continues on this Gottlieb System 80b pinball machine Raven, but there’s a problem with the light matrix. Certain lights are not properly activating. I go through the process of fixing some lights that aren’t working properly. This video chronicles the entire process of diagnosing what the problem is. I go over the schematics and how to use a logic probe to test the circuit.

Repairing a faulty pinball chip

Work continues on a Gottlieb “Raven” System 80b pinball machine.

If you watched the previous videos, we had a problem with some lights not being activated by the MPU and traced it to an issue with an IC – now we’re going to replace the IC. For more visit: and