E: 77. Heat Sink Thermistor Error (Outdoor Unit) - Fujitsu ABYG36KRTA Service Manual

2-23. 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 outdoor temperature thermistor resistance value, refer to
sistance values"
• 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 02-17.
If the voltage does not appear, replace inverter PCB.
2-23. E: 77. Heat sink thermistor error (Outdoor unit)
Error code
↓
on page 03-58.
↓
↓
End
Heat sink temperature thermistor short or open detected
Connector failure
Thermistor failure
Inverter PCB failure
"Thermistor re-
"Wiring diagrams"
- (03-28) -
E: 77
in Chapter 2.
2. Troubleshooting with error code