Whirpool AWZ 412 trips, sparks, then 'dies'

I have a Whirpool AWZ 412 front-loading washer which 3 days ago has tripped the switch board (I wasn't there when this 1st happened). I came from work, found the wet clothing wet inside, and re-started it again. It tripped after filling, but (I believe) before tumbling -- there was a bright spark, and the thing was left locked and filled with water. Removed the cover and looked underneath -- there was a bit of black dusting on the motor wires, but not clear if this is the charring or worn belt dust, i.e. no obvious suspects. I then tried to watch it trip in real-time, to see where the spark would come from, but now it won't do anything: no filling, and no relays switching, except for locking the door and showing the Active LED.

I've previously replaced the drain pump, it worked fine for a few months with the new pump. Also, found a broken thermostat connector which I soldered back together and tested. Don't think it's the thermostat though, as we never use the drying function. Another odd thing (but could be irrelevant) is this loose red wire next to the water pressure sensor. It's not properly terminated, but does not appear charred either (pic)