Fujitsu AUXB04GALH Service Manual page 131

Trouble shooting 43
OUTDOOR UNIT Error Method:
Heat Sink Temp Sensor Error
Detective Actuators:
Heat sink temp. sensor
Forecast of Cause :
1. Connector connection defective, open
2. Sensor defective
3. Inverter PCB defective
Check Point 1 : Check the connector connection and cable open
Connector connection state check
Cable open check
OK
Check Point 2 : Check the sensor
Sensor characteristics check (Disconnect the sensor from the PCB and check.)
* For the sensor characteristics, refer to the "Service Parts Information 24".
OK
Check Point 3 : Check voltage of Inverter PCB (DC5.0V)
Inverter PCB (CN360: 1-2) voltage value = 5V
Remove the sensor from Inverter PCB, check the voltage.
THERMISTOR (HEATSINK)
BLACK
1 1
CN360
2 2
BLACK
Heat sink temp. sensor (CN360: 1-2)
If the voltage does not appear, replace Inverter PCB.
Caution
By changing of DIP SW 4-2 to ON, the Back-up operation can start when the active outdoor unit exists on the multi outdoor unit connection.
(Stand alone outdoor unit is impossible)
The following conditions will be concerned in use of back-up operation. (Please do not use the system with back-up operation for long time.)
- The operating compressor life time becomes shorter.
- The operating performance may drop due to the limited active compressor(s).
- The compressor may stop frequently by protection controlling.
*In order to keep the operating capacity, the release of the Low noise mode setting might be necessary.
Indicate or Display:
E77. 1
Outdoor Unit : E. 7 7. 1
Indoor Unit : Operation LED 9 times Flash, Timer LED 15 Times Flash,
Error Code : 9 U / 7 7
Detective details:
Heat sink temp. sensor open/short detected
04-55
Filter LED Continuous Flash.
DC