Thanks for all the advice. Washer is working as it should after shocks were replaced. In order to replace the shocks, we had to remove the motor control board for access and if there had been a loose connection somewhere, we presume it was taken care of when the motor control board was re-installed.
In the end, it seems the broken shock was the culprit causing the F04 error.
- Samurai Appliance Repair Man likes this