39
C Check of indoor P.C. board and indoor fan motor
Turn OFF the power supply.
Remove the indoor fan motor connector
CN211 and the vane motor connector
CN151 from the indoor electronic control
P.C. board and turn ON the power supply.
Does the unit operate with the remote
controller?
Does OPERATION INDICATOR lamp light
up by pressing the emergency operation
switch?
Yes
No
Measure the resistance between
CN211 and of the indoor fan motor
connector.
Short circuit:
Replace the indoor fan motor.
Turn OFF the power supply.
Check both “parts side” and “pattern
side” of the indoor power P.C. board
visually.
Replace the varistor (NR11)
and fuse (F11). *3
Are the varistor (NR11)
burnt and the fuse (F11)
blown?
No
No
Yes
Yes
Be sure to check both the fuse
and the varistor in any case.
Is the fuse (F11) blown
only?
Measure the resistance between
CN211 (+) and (-) of indoor fan
motor connector. *1, *2
Yes
Is the resistance 1MΩ or more?
Replace the fuse (F11) and the
indoor fan motor. *3
No
Replace the fuse (F11). *3
Measure the resistance of resistor (R111)
(
MSZ-AY25/35/42VG/VGK/VGKP
)/
reac-
tor (L112)
(
MSZ-AY50VG/VGK/VGKP
)
on the indoor power P.C. board.
No
Replace the indoor electronic
control P.C. board and the indoor
fan motor.
Replace the indoor electronic control P.C. board.
Measure the resistance of the vane
motor coil.
Refer to 10-5.
Short circuit:
Replace the vane motor and the indoor
electronic control P.C. board.
*1. The fan motor connector’s lead wire is red, whereas
is black.
*2. Connect “+” of the multimeter to fan motor connector’s
lead wire, and “-” to lead wire, otherwise the
resistance cannot be measured properly.
*3. Please replace the fuse after removing the indoor
power P.C. board from the electrical box.
Is the resistance of resistor (R111)
(
MSZ-AY25/35/42VG/VGK/VGKP
)
approximately 3.9Ω
/
reactor (L112)
(
MSZ-AY50VG/VGK/VGKP
)
approximately 4.3Ω?
Yes
Terminal
P.C. board
Varistor
(NR11)
LD201(T)
Fuse (F11)
Indoor electronic
control P.C. board
GND
R111
L112
LD201(M)
OBH932