Mitsubishi Electric MUZ-FD25VA-E1 Service Manual page 32

Outdoor fan motor does not operate.
Check of outdoor fan motor
I
Disconnect CN932 from the inverter P.C. board,
and measure the resistance of the outdoor fan motor.
Is the outdoor fan motor
normal?
(Refer to 11-4.)
Yes
Replace the inverter P.C. board.
Inverter does not operate.
Check of power supply
J
Disconnect the connector
(CN61) between compressor and
intelligent power module.
Turn ON power supply and press
EMERGENCY OPERATION
switch.
Does POWER lamp on the
indoor unit light up?
Yes
Is there voltage
280 ~ 370 VDC
between DB61 (+) and
DB61 (–) on the
inverter P.C. board?
(Refer to 11-6.1.)
No
Check the electric
parts in main circuit.
No
Replace the outdoor fan
motor.
Rectify indoor/ outdoor
connecting wire.
Yes
Is there voltage 230 VAC
No
between the indoor
terminal block S1 and
S2?
Dose LED on the inverter
Yes
P.C. board light up or
flash? (Refer to 11-6.1.)
Yes
If light up, ok.
If flash, refer to
11-3.
Replace the indoor
No
electronic control
P.C. board.
No
Replace the inverter
P.C. board.
DB61
Inverter P.C. board
(Solder side)
32
280~370 VDC