Fujitsu Comfort Series Service Manual page 37

Troubleshooting 11
OUTDOOR UNIT Error Method:
Outdoor Thermistor Error
Detective Actuators:
Outdoor temperature thermistor
Forecast of Cause :
1. Connector connection failure, open
2. Thermistor failure
3. Main PCB failure
Check Point 1 : Check the connector connection and cable open
Connector connection state check
Cable open check
OK
Check Point 2 : Check the thermistor
Thermistor characteristics check
(Disconnect the thermistor from the PCB and check.)
* For the thermistor characteristics, refer to the "Service Parts Information 5".
OK
Check Point 3 : Check voltage of Main PCB (DC5.0V)
Main PCB P5:1-3 voltage value =5V
Remove the thermistor from Main PCB, check the voltage.
1 2 3
1 2 3
P5
If the voltage does not appear, replace Main PCB,
and execute the check operation again.
Indicate or Display:
Green 7 flash / Red 4 flash
Detective details:
Outdoor temperature thermistor short or open detected
03-12
Outdoor unit : No indication
DC