Mitsubishi Electric MSZ-EF22VEW Service Manual page 26

C Check of indoor P.C. board and indoor fan motor
Turn OFF the power supply.
Remove indoor fan motor connector CN211
from indoor power P.C. board and 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 EMERGENCY OPERATION
switch?
No
Turn OFF the power supply.
Check both "parts side" and "pattern
side" of the indoor power P.C. board
visually.
Measure the resistance of reactor
(L111) on the indoor power P.C.
board.
Indoor power
Fuse (F11)
P.C. board
CN211
Indoor electronic
control P.C. board
CN10A
GND(JPG)
Measure the resistance of indoor fan
motor.
Refer to 10-5.
Measure the resistance of the vane
motor coil.
Yes
Refer to 10-5.
Replace the varistor (NR11)
and fuse (F11). 3
Yes
Is the varistor (NR11)
burnt and the fuse (F11)
blown?
Be sure to check both the fuse
and the varistor in any case.
Is the fuse (F11) blown
only?
Yes
Measure the resistance between
CN211 (+) and (-) of indoor fan
motor connector. 1, 2
Is the resistance 1MΩ or more?
Yes
Replace the fuse (F11). 3
Is the resistance of reactor
(L111) approximate 2.2 Ω ?
Is the approx. 5 VDC between 5 V
(+) and JPG (GND) (-) of the indoor
electronic control P.C. board? Is there
approximate 9 V to 13 VDC between
Varistor
12 V (+) and JPG (GND) (-) of the
(NR11)
indoor electronic control P.C. board.
L111
Are connector CN10A on the
indoor electronic control P.C.
board or lead wires discon-
nected?
Replace the indoor electronic control P.C. board.
26
Short circuit:
Replace the indoor fan motor.
Short circuit:
Replace the vane motor and the indoor
electronic control P.C. board.
No
No
1. The fan motor connector's
whereas is black.
2. Connect "+" of the tester to fan motor connector's
lead wire, and "-" to
resistance cannot be measured properly.
3. Please replace the fuse after removing the indoor
power P.C. board from the electrical box.
Replace the fuse (F11) and the
indoor fan motor. 3
No
No
Yes
Yes
No
Yes
No
lead wire is red,
lead wire, otherwise the
Replace the indoor
power P.C. board and
the indoor fan motor.
Replace the indoor fan motor.
Connect the connector or repair discon-
nection.