In addition to collecting lighting related things, I also collect fire alarms (technically lighting related as well. Among my collection I have many devices that contain strobes. Most of them work, but I do have two that don't work that I would like to get working. Specifically, a Simplex 2903-9150 120V strobe plate, and a Space Age Electronics A32 white strobe plate. Does anyone on this site have experience in strobe circuits or repairing them?

I don't know about fire alarm strobes, but I have some strobe light drivers and I know how they work. Usually they consist of a small step up transformer, the primary of which is driven by the discharge of a small capacitor. This sends an HV pulse to the antenna outside the tube which discharges a larger capacitor through the tube. I would say the most likely thing to go wrong is in the triggering circuitry. This is sometimes done with a neon indicator, but could be more complicated with fire alarms if they are supposed to strobe synchronously. Usually they aren't that complicated, just start checking the different components until you find a bad one. Do you have a picture of the board?