Samsung DMR78AHS/XAC Service Manual page 58

4. Troubleshooting
Error
Error type
mode
3. Check the driving signals for the power relay
New PBA
3-1.Check the driving signals for the power relay
Power Relay error None
4. Check the operation of the Power Relay
4-20
Checking Method
: Measure the voltage between pin 6 (amber) and pin
1 (black) of the CN7 connector on the main PBA.
When the door is open or before the cycle starts.
➢
 Normal: 10.5 to 13 V
After the cycle has started by closing the door and
➢
pressing the Power key.
 Normal: 1 V
: Measure the voltage between pin 6 (amber) and pin
1 (black) of the CN302 connector on the main PBA.
When the door is open or before the cycle starts.
➢
 Normal: 9.5 to 13 V
After the cycle has started by closing the door and
➢
pressing the Power key.
 Normal: 1 V
: Start the cycle by pressing the Power Key.Measure
the operation voltage between the terminal (black wire
+ black wire) of the Heater Relay and the terminal
(yellow wire+ amber wire) of the Power Relay
Caution
Check the color of the wires of the Power Relay and
the Heater Relay.
Nomral: 120V
➢
Corrective actions
- Faulty: Replace the main PBA assy.
- Faulty: Replace the power relay.
Power Relay Terminal
(yellow wire + amber wire)
Heater Relay Terminal
(black wire + black wire)