Fujitsu ASUG12LZBS Service Manual page 64

2-16. E: 72.X. Compressor thermistor error (Outdoor unit)
Indicator Indoor unit
Outdoor unit main PCB
Detective actuator
Compressor temperature thermistor
Forecast of cause
Check point 1. Check connection of connector
• Check if connector is loose or removed.
• Check erroneous connection.
• Check if thermistor cable is open
→ Reset power when reinstalling due to removed connector or incorrect wiring.
Check point 2. Remove connector and check thermistor resistance value
• For the compressor thermistor resistance value, refer to
values" on page 03-77.
• If thermistor is either open or shorted, replace it and reset the power.
Check point 3. Check voltage of main PCB
Make sure circuit diagram of outdoor unit and check terminal voltage at thermistor
(DC 5.0 V).
NOTE: For details of thermistor connector, refer to
TECHNICAL DATA AND PARTS LIST on page 02-14.
(09-15 model: P15)
If the voltage does not appear, replace main PCB.
2-16. E: 72.X. Compressor thermistor error (Outdoor unit)
Operation indicator
Timer indicator
Economy indicator
Error code
When compressor temperature thermistor open or short
circuit is detected at power on or while running the
compressor
↓
↓
"Wiring diagrams"
↓
End
- (03-28) -
7 time flash
2 time flash
Continuous flash
E: 72
Connector failure
Thermistor failure
Main PCB failure
"Thermistor resistance
in Chapter 2.
2. Troubleshooting with error code