Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Refit connector X20 at the PCB from the previous
test if you have not already done so
Remove the fan connector and make safe
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

With the fan disconnected does the display illuminate/show information?