This is the same Frigidaire FEX831FS4 washer and dryer combo which few weeks ago due to unbalanced load the switch wire had snapped. I spliced the wire back together and washer worked again for a month.
However, the washer again stopped to work in the middle of cycle while it was full with water. This time it was small load. Washer was completely unresponsive until a small click, like relay, is heard coming either from door lock or most likely motor area (not yet 100% sure which one). When that click happens I am able to fast forward to the end of cycle and washer was able to drain all the water from the drum. And after attempting to start a new cycle it was able to fill with water, but it won't ever spin. After filling with water, the washer again becomes unresponsive until the same click happens again.
Also, the knob on front controller board (where is timer) has started to make this strange humming noise, which makes me think that motor may be still be good and that the washer could be repairable.
What could it be the root cause this time? Why the strange humming noise coming from that knob? Could it be that this is another issue creeping up due to unbalanced load that happened month ago - I remember that the wire that snapped appeared a little burnt in the are - possibly because of touching the washer frame.