Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Disconnect the low voltage plug at the fan (back left of fan)
Reconnect X4 at the PCB if you have not already done so
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Does the display operate with the fan disconnected?