Kenmore Mini Fridge
Weird Behaviour
1) Relays, Switches, PTC Starter check out ALL GOOD. (More details on testing available.)
2) Compressor STARTS when the fridge is FLAT ON ITS FACE (doors closed, lying down the on carpet), BUT ...
3) When the unit is placed UPRIGHT IN NORMAL OPERATING ORIENTATION, the Compressor DOES NOT START at all -- it just hums, indicating that it is receiving some power.

QUESTIONS:
A) Is there any gravity/attitude sensor here? The wiring diagram is quite simple, with no active electronics, so that’s unlikely.
B) Is the orientation of any of the other components relevant when they are good? What component features/faults may exhibit such behaviour?