Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove connector X17 from the PCB
Measurement:
Test 1. Measure for resistance across the blue and brown leads of connector X17.
Expected resistance approximately 0.770 Kohms.
Test 2: Measure for resistance across the brown lead of connector X17 and a suitable earth connection.
Expected resistance greater than 1 Mohm.
Expected resistance approximately 0.770 Kohms.
Test 2: Measure for resistance across the brown lead of connector X17 and a suitable earth connection.
Expected resistance greater than 1 Mohm.
Isolate as per TOPs P4
and refit as necessary