Samsung DMR78AHS/XAC Service Manual page 44

4. Troubleshooting
Error type Error mode
1. Check the connections of the Heater connectors.
2. Check the resistance between both ends of the Heater.
: Check the resistance between both ends of the Heater directly, or check
the resistance between the red wire of the Heater Relay and the amber
and yellow wires of the Power Relay, respectively.
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 Check after disconnect circuit breaker or power cable.
3. Check the connections of the Heater Relay.
: Check the voltage between the red wire of the Heater Relay on the base
and the yellow and amber wires of the Power Relay.
Heater error HE
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4. Check the driving signals for the Heater Relay.
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New PBA
4-1.Check the driving signals for the Heater Relay.
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4-6
Checking Method
Normal: Approx. 13Ω
Normal: 120V (while operating)
- Measure the voltage between pin 6 (amber) of the Main PBA CN7
connector and pin 2 (red) of the CN7 connector.
When the Heater is off: 10.5 to 13V
When the Heater is operating: < 0.5V
- Measure the voltage between pin 6 (amber) of the Main PBA CN302
connector and pin 2 (red) of the CN302 connector.
When the Heater is off: 9.5 to 13V
When the Heater is operating: < 0.5V
Corrective actions
- Reconnect the Heater connectors.
- Faulty: Replace the Heater.
- Reconnect the Heater Relay connectors.
Power Relay Heater Relay
yellow + amber red wire
wire connector connector
- Faulty: Replace the Main PBA assy.
- Normal: Replace the Heater Relay.
New PBA