Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove connector J1 from the PCB and position it away from the PCB
Replace the blown fuse with a new one of correct size and rating
Replace the blown fuse with a new one of correct size and rating
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
| Isolate Mains Power to appliance as per TOPs P4 |
Remove the fuse and measure the resistance across it.
Has the fuse blown again?
Continuity / zero resistance = fuse has not blown
O.L / high resistance = fuse has blown
Isolate as per TOPs P4
and refit as necessary