Testing Driver Chips

[Matt R]

Hello!

I often find myself having to test and replace the NJM3773D2 chip. It's also fairly common that I need to replace the NJM3775D2, PBL3775/1N as well as the NJM3771D2 chips.

These are used in old stage lights which are no longer being built. Normally, I can repair these rather rapidly. However, I've recently been sent a large case of the logic boards to be repaired. Generally I cannibalize a known working stage light, install the "dead" logic board, and run tests to find which motors don't fire up. However, that's no longer possible.

I'm not very good with circuit design and I was wondering if I could get some help here. I want to make a simple circuit where I can fire up one of these chips and test it to know that it works. I do have an Arduino available if that helps any. I also have stepper motors available that match the type used in our stage lights.

Any bit of assistance would be so much appreciated as I don't even know where to begin. Circuitry really isn't my thing! I just know how to replace the bad chips.

[tautech]

Welcome to the forum.

Not that I could be of much help, but maybe advice.

Knock up a block diagram so all watching can understand.
Provide a link to any device datasheets.
Maybe pics?
What diagnostic and repair tools do you have?

What are the motors for, pan and tilt?

[Shock]

Datasheets typically have example circuits in them. That is where you need to start. But ideally you want to get a proper test environment, charge them accordingly so you can afford to buy one to guarantee the quality of your work or get a loaner. This is quite a common occurrence in repair.