Confirming something here...
I have a Classic that shows 0 Ohms across PV+/PV-. So the power board is suspect, guessing shorted FETs. From previous forum posts here and elsewhere, I understand FETs can fry with excessive PV voltage... over and above HyperVOC threshold. Is it register 4123 that shows max voltage supplied for the life of the unit? Any other register(s) to look at?
I do not recall the exact register but if the system was running all along it should not be able to go over voltage. I would call in and chat with Jim Parish and he can assist you