Tech Advice Needed - GNX3 Pedal

Hey everyone, this is my first post on the forum but I really need some assistance. I got a Digitech GNX3 Pedal as a hand-me-down, Its been kept in good condition I'm just having one huge problem with it -- occasionally it just decides that it doesn't want to stay on one effects setting. It will rapidly cycle through a bunch of different patches over and over. I have a pretty technological background but I don't know much of anything about guitar pedals. Anyone know what might be causing this? My best guess is just old wires but I'd like to try and fix it myself. Thanks!

I had a GNX2 back in the day that I put a lot of hours of play on! Right on!

So, these are digital pedals and the power supply is 18.5 volts, I believe. Be sure that you're using the proper power supply for what the pedal requires. Be sure that your supply is giving at least the minimum mA load for the board as well. Even if the volts are there, the mA need to be sufficient. If that's all good, the next thing in the diagnostics would be to duplicate what the board is doing by finding which switch/button does the same thing. There you can find a starting point. You could have a faulty button or dirt/grime that is making a connection. That'd be where I would start. If the power is good and the buttons are free from sticking, you're probably dealing with a board malfunction.