Fujitsu ARYG72LHTA Service Instruction page 58

Trouble shooting 21
OUTDOOR UNIT Error Method:
Discharge Thermistor Error
Detective Actuators:
Discharge 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 8".
OK
Check Point 3 : Check voltage of Main PCB (DC5.0V)
(CN146:1-2) voltage value = 5V
Main PCB ain PCB
Remove the thermistor from Main PCB, check the voltage.
Discharge temperature thermistor (CN146:1-2)
If the voltage do not appear, replace Main PCB
and execute the check operation again.
Indicate or Display:
Error code : 71
Detective details:
Discharge temperature thermistor short detected
Discharge thermistor open detected
1 2 3 4
1 2 3 4
CN146
,
Outdoor unit :
PUMP
POWER
DOWN
ERROR
MODE (L1)
7
2
DC
02-22
LOW PEAK
NOISE CUT
(L2) (L3) (L4) (L5) (L6)
1