Set Appliance State:

Mains Power Off
Set Multimeter to DC Volts Set meter to measure DC Volts
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure the DC voltages between each of the test points at connector X51 on the back of the display PCB as listed below to a suitable earth point.
The Voltages should conform approximately to the table below:
Test pointDC Volts
GND0
RES_SW 4.7
EBUS21.8
5V5
24V24
PEBUS5