Set Appliance State:

Mains Power Off
On/Off Switch ON
No Demands
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Are there any lights illuminated on the panel?
Note:
The appliance name/heat input shown on the user controls facia may differ from the appliance you are working on but the operation remains the same.