Heatsink Temperature Trouble - Mitsubishi PUMY-P60NKMU Technical & Service Manual

Check code
4230
Abnormal points and detection methods
Abnormal if TH8 detects a temperature outside the specifi ed range during
compressor operation.
TH8: Heatsink temperature thermistor
●Diagnosis of defectives
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Is 5110 displayed when restart?
Does the fan rotate during
compressor operation?
Is there any obstacle which blocks
an airfl ow around the heatsink?
Is 5110 displayed when restart?
Check the wiring and connector connection TH8.
Is there any abnormality such
as a disconnection, looseness or
breakage?
Check the resistance of TH8.
Is the resistance normal ?
OCH502C

Heatsink temperature trouble

Diagnosis
Yes
No
No
Yes
Yes
(air path blocked)
(no obstacle)
No
Yes
No
TH8 temp. - resistance characteristic
No
Yes
Causes and check points
Blocked outdoor fan
Malfunction of outdoor fan motor
Blocked airfl ow path
Rise of ambient temperature
Characteristic defect of thermistor
Malfunction of input circuit on outdoor power board
Malfunction of outdoor fan driving circuit
Refer to the diagnosis of check code 5110.
Refer to the diagnosis of check code 4400.
Improve the airfl ow path.
Connect the wiring/connector properly.
Replace it in case of a breakage.
0 ···180kΩ 25 ···50kΩ 50 ···17kΩ
70 ···8kΩ 90 ···4kΩ
Replace the thermistor
(Defective thermistor).
Replace the outdoor power board
(Defective outdoor power board).
55
Remedy