Fujitsu AUXG45LRLB Service Instruction page 63

Trouble shooting 23
OUTDOOR UNIT E rror Method:
Outdoor Thermistor Error
Detective Actuators:
Outdoor temperature thermistor
Forecast of C ause :
1. Connector connection defective, 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 8".
OK
Check Point 3 : Check voltage of Main PCB (DC5.0V)
Main PCB 30/36(CN62:1-3) 45/56(CN61:1-3) voltage value =5V
Remove the thermistor from Main PCB, check the voltage.
[30/ 3 ] 6
Compressor temperature thermistor(CN62:1-3)
If the voltage does not appear, replace Main PCB If the voltage does not appear, replace Main PCB
the check operation again.
Indicate or Display:
Error code : 74
Detective details:
Outdoor temperature thermistor short or open detected
3 2 1
3 2 1
CN62
Outdoor unit : Model 45.54
POWER
MODE
2
4 [ 5 / 54]
Compressor temperature thermistor(CN61:1-3)
, and execute
02-25
PUMP LOW PEAK
DOWN NOISE CUT
ERROR
L ( ) 1 L ( ) 2 (L3) (L4) (L5)
7 4
3 2 1
3 2 1
CN61
L ( ) 6
DC