Turned the machine on its side, disconnected the drain hose, and inspected the pump.
The pump looked fine, so I continued disassembling the cover plate for the belt
Noticed
The belt greasy, couldn't find where grease came from
Ordered a new pump just to be safe, and ordered a new belt
Degreased the pulleys, installed a new belt, installed a new pump, and had a customer run a load,
All worked perfectly. I'm totally happy.
The customer had another true appliance repairman and he changed out the mainboard, but it didn't fix the problem and so we just threw money away,