Wow, this model seems to have three electronic boards plus the clock!
All the F5 error codes on the tech sheet all relate to one board or another, but they are all F5 followed by another code.
Have you looked at it yourself yet?
Guess I would start by inspecting all the electronic boards for any damage to see if there is any obvious damage, bad solder joints or bad connections. Would also check the wire harness and the power cord connections.