I'm struggling to fix an electronic circuitboard -- can anyone offer suggestions?
It's a circuitboard from a motorcycle instrument panel, manufactured in 2019. It has a layer on each side. I don't know if it has any internal layers.
There are two push switches, and the controller seems to think one of the switches is continually pressed.
Testing the switch with a multimeter, it looks fine. It's normally open, and when pressed, closes the circuit with very low resistance. This is identical to the other, working, button.
The circuitboard has some test points, including for GND and the switches.
When my multimeter is connected to GND and the test point for the bad switch, the results appear good.
ie. No connection normally, and then a very low resistance connection when pressed.
I'm trying to work out what else could be the problem. Maybe the connection to the microcontroller has shorted out against a neighbouring connection?
I can't visually see anything like that, but I don't have a circuit diagram and the circuitboard has a layer on top of it obscuring the tracks.
Maybe a track has somehow broken inside the circuitboard and shorted to ground? I can't see any visual damage, and I guess I wouldn't know how to fix this even if there was.
Are there other possibilities I'm missing?