Mitsubishi Electric SEZ-KD25VAQ Technical & Service Manual page 34

6-7. DC FAN MOTOR (FAN MOTOR/ INDOOR CONTROLLER BOARD)
Check method of DC fan motor (fan motor / indoor controller circuit board)
1 Notes
· High voltage is applied to the connecter (CNMF) for the fan motor. Give attention to the service.
· Do not pull out the connector (CNMF) for the motor with the power supply on.
(It causes trouble of the indoor controller circuit
Self check
2
Symptom : The indoor fan cannot turn around.
Check the fuse (FUSE) on indoor
controller board.
Did the fuse blow?
No
Wiring contact check
Contact of fan motor connector (CNMF)
Is there no contact failure?
Yes
Power supply check (Remove the connector (CNMF))
Measure the voltage in the indoor controller circuit
TEST POINT 1 : V (between 1 (+) and 4 (-) of the fan connector): V
DC
TEST POINT 2 : V (between 5 (+) and 4 (-) of the fan connector): V
CC
Is the voltage normal?
No
Replace indoor
controller board.
Check the operation.
NG
Replace the fan motor.
board and fan motor.)
Check the drain pump (DP)
Yes
Is the resistance between
terminals normal?
No
Replace drain pump (DP).
Wiring recovery
No
board.
Replace the fan motor.
Yes
Check the operation of fan.
Replace indoor controller board.
OK
END
Replace indoor controller board (I.B).
Yes
Replace fan motor (MF).
DC310~340V
DC
DC15V
CC
Yes
OK
END
NG
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