Microwave loses all power, LEDs, etc. Works again after power drain.
I have a GE cabinet mount microwave model PVM9005EJ2ES (manufactured NOV 2016) that started acting up a few months ago. The first few times, it tripped the Arc fault breaker in the garage. (Test button trips it and allows normal reset.) The gas oven shares this circuit. I would reset it, and the microwave was fine. Then a week or so later, microwave would have no lights on it, clock blank, no beeps on the control panel, no interior light. Nothing. No signs of power. If I unplug it and plug it back in immediately, it's still dead. If I unplug for at least 30 seconds, then plug it back in, the lcd clock does a lamp test then begins working normally. I set the clock and it appears to run fine. (For a while. Sometimes days, couple weeks, or multiple times a day.) To rule out the breaker, I ran a large gauge extension cord to another circuit in the house, not on gfci, or afci. Same issue. I'd walk into the kitchen, blank clock and no signs of power.
I would agree with you assessment that is probably is the caps but the best way to find a problem is to open it up. Just be sure to short the caps & coils before you hand touches anything