gofar99 Messages: 1667 Registered: May 2010 Location: Southern Arizona
Illuminati (4th Degree)
That is rather odd. Based on how a lot of gear works I suspect either voltage fluctuation or interference. I would rate the voltage issue more likely though. It is likely that there is some sort of power filtering in the unit or in the wiring going to it. That would be the first place to check. A bad ground connection there might cause the problems. A bad filter could also introduce EMI into the unit and fool it into thinking it was some sort of change signal. If the unit has remote control capability then it is also possible that something is tricking it into changing. I know these are rather general concepts and the average person will not be able to check on them. I would expect that the best way to solve the problem is to take it in for service. Likely a costly experience. It might be cheaper to just replace it.
You are absolutely right about these concepts being a bit challenging for someone like myself. I'll look to see what its replacement will cost me; if, like you had mentioned, it's on the higher side, I'll just leave it alone as it doesn't bug me enough to justify a costly replacement.
I think Bruce was suggesting looking into the common problems that you can check. Check the power, check the ground. Possibly consider adding a series coil and a shunt capacitor on the power line to reduce noise. Check that wiring isn't frayed.
It's really hard to tell what's going on inside the radio without an oscilloscope. And even then, a digital problem requires some kind of digital analyzer like a debugger.
Basically, something like this is hard to troubleshoot because of the lack of visibility in the internal mechanism(s). Looking for things like bad connections and ground loops are always good suggestions, but beyond that, it's probably best to swap the radio.