GE Spacemaker XL1800

Heating element is working fine, but sometimes the light and turntable work sometimes not. When the turntable does not work heating is uneven and the microwave is basically not usable.

Anyone know if there is a known issue related to these symptoms? My guess is something is loose/shorted since it will work fine at times - usually after closing the door a little harder than necessary, jarring something (back into place) is my guess.

I opened the control panel but nothing is visibly out of whack there.

Thanks,
Jim