Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Disconnect the rectification lead
(rear lead of the three electrodes) and make safe
Refit connector LV1 at PCB
Ensure NO demands
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance.
Does the appliance now reset and enter standby
or does it still go to fault code?