Mitsubishi Electric Mr.Slim PCA-M35KA2 Service Manual page 31

9-6-2. DC Fan motor (fan motor/indoor controller circuit board)
Check method of DC fan motor (fan motor/indoor controller circuit board)
1 Notes
· High voltage is applied to the connector (CNMF) for the fan motor. Pay 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 board and fan motor.)
2 Self check
Symptom: The indoor fan cannot rotate.
Wiring contact check
Contact of fan motor connector (CNMF)
Is there contact failure?
No
Power supply check (Remove the connector (CNMF))
Measure the voltage in the indoor controller circuit board.
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?
Yes
Sensor signal check
Measure the voltage between CNMF 7 and 4 0 VDC
and 15 VDC in the indoor controller circuit board.
Does the voltage repeat
0 VDC and 15 VDC?
Yes
Replace the indoor
controller board.
Check the operation.
Fail
Replace the defective fan motor.
Symptom: The fan motor does not stop when pressing the stop button on the remote controller.
The fan motor starts to rotate when turning on the breaker.
Process: The connector for emergency operation on the indoor controller board is possibly set to ON.
Check the setting of SWE.
Set SWE to OFF if it is set to ON.
OCH752
Yes
Correct the wiring.
No
Indoor controller board fuse check
Is the fuse normal?
Replace the indoor
controller board.
Check the operation.
Replace the defective fan motor.
No
Replace the defective fan motor.
OK
Complete.
31
310–340 VDC
DC
15 VDC
CC
No
Yes
Fail
Check the operation.
OK
Complete.
Fail
Yes
Check the operation of fan.
Fail
Replace the indoor
controller board.
Replace the fuse.
OK
Complete.
OK
Complete.