E: 77. Heat Sink Thermistor Error (Outdoor Unit) - Fujitsu General ARXG45KHTB Service Manual

2-17. E: 77. Heat sink thermistor error (Outdoor unit)

Wired remote
Indicator
controller
Detective actuator Heat sink 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 Heat sink thermistor resistance value, refer to
ues" on page 03-52.
• If thermistor is either open or shorted, replace it and reset the power.
Check point 3. Check voltage of inverter 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 02-15.
If the voltage does not appear, replace inverter PCB.
2-17. E: 77. Heat sink thermistor error (Outdoor unit)
Error code
Heat sink temperature thermistor short or open detected
↓
↓
"Wiring diagrams"
↓
End
- (03-23) -
E: 77
Connector failure
Thermistor failure
Inverter PCB failure
"Thermistor resistance val-
in Chapter 2.
2. Troubleshooting with error code