Mitsubishi Electric MUZ-GC25VA-E1 Service Manual page 32

Outdoor fan motor does not operate.
Check of outdoor fan motor
I
MUZ-GC25VA MUZ-GC25VAH
Check the resistance of fan motor. (Refer to 11-4.)
Disconnect the connector CN771 on inverter P.C.
board.
Disconnect the connector (CN61) between
compressor and power transistor module.
Turn ON the power supply and press the
EMERGENCY OPERATION switch.
MUZ-GC35VA MUZ-GC35VAH
Is the resistance
between each terminal of
outdoor fan motor normal?
(Refer to 11-4.)
No
Replace the outdoor fan
motor.
Is the resistance of fan
motor normal?
Yes
Does upper lamp of
OPERATION INDICATOR
lamp on the indoor unit
light up?
Disconnect CN932
Yes
from the inverter
P.C. board.
Inverter P.C. board
(Solder side)
CN931
CN932
No
Replace the outdoor
fan motor.
3 minutes after, is there
voltage 230V AC
between CN771 2 and
3 on the inverter P.C.
board?
Yes
Replace the
outdoor fan motor.
Turn ON the
power supply.
( Fixed to either 5V or 0V DC)
32
No
Replace the inverter
P.C. board.
Rotate the outdoor fan slowly
by hand, and measure the
voltage of CN931 (Measurement
of feedback output).
Between 1(+) and 5(-)
Between 2(+) and 5(-)
Between 3(+) and 5(-)
Does the voltage between
each terminal repeat 5V
No
and 0V DC by turns?
Yes
Does the outdoor fan
rotate smoothly?
No
Yes
Check the inverter P.C. board.
(Refer to 11-5. M)