Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to DC Volts Set meter to measure DC Volts
Remove the display from the facia
Remove connector ST5 from the PCB
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Test 1:
Measure the DC voltage between pins 1 and 4 at connector ST5.
Expect approximately 4.6VDC.
Test 2:
Measure the DC voltage between pins 3 and 4 at connector ST5
Expect approximately 23VDC.
Test 3:
Measure the DC voltage between pins 6 and 4 at connector ST5.
Expect approximately 4.6VDC.
Are the voltages measured as expected?