Mitsubishi Electric Mr.Slim MSY-D30NA, Service Manual

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25
A Check of indoor fan motor
9-6. TROUBLESHOOTING FLOW
The indoor fan motor error has occurred, and the indoor fan does not operate.
Turn OFF the power supply.
Is there any foreign matter that
interferes the rotation of the line
fl ow fan?
Yes
No
Remove the foreign matter and
adjust the line
fl ow fan.
Pay enough attention to the high voltage on the fan motor connector CN211.
Turn ON the power supply, wait 5 seconds or more, and then press
EMERGENCY OPERATION switch.
Measure the supply voltage as follows within 12 seconds after EMER-
GENCY OPERATION switch is pressed.
If more than 12 seconds passes by, turn OFF the power supply and
turn ON it again, then measure the voltage.
1. Measure the voltage between CN211 (+) and (-).
2. Measure the voltage between CN211 (+) and (-).
If 12 seconds or more passes after EMERGENCY OPERATION switch is
pressed, the voltage mentioned above 2 goes 0 VDC although the indoor
electronic control P.C. board is normal
Is there 294/325 VDC between
CN211 (+) and (-), and does the
voltage between CN211 (+) and
(-) rise to the range of 3 to 6 VDC
within 12 seconds after EMERGEN-
CY OPERATION switch is pressed?
Replace the indoor fan motor.
CN211
Indoor electronic
control P.C. board
Yes
No
The indoor fan motor error has occurred, and the indoor fan repeats "12-second ON and 30-second OFF" 3 times, and then stops.
Measure the voltage between CN211
(+) and (-) while the fan motor is
rotating.
Replace the indoor electronic control P.C. board.
Is it unchanged holding
0 or 15 VDC?
No
(Changed)
Yes
(Unchanged)
Replace the indoor electronic control P.C. board.
Replace the indoor fan motor.