Mitsubishi Electric MSZ-GS06NA - U1 Service Manual page 46

C Check of indoor electronic control P.C. board and indoor fan motor
MSZ-GS06/09/12/15NA
MSY-GS09/12/15NA
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 the emergency operation
switch?
No
Turn OFF the power supply.
Check both "parts side" and "pattern
side" of the indoor terminal P.C.
board visually.
Measure the resistance of resistor
(R111) on the indoor power P.C. board.
Indoor electronic control
P.C. board
GND
Indoor terminal
P.C. board
Indoor power P.C. board
Fuse
Varistor
(F11)
(NR11)
OBH874A
Measure the resistance between
CN211 and of the indoor fan motor
connector.
Measure the resistance of the vane
motor coil.
Yes
(Refer to 9-5.)
Replace the varistor (NR11)
and fuse (F11). *3
Yes
Are 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
5 V DC
CN151
CN10A
12 V DC
R111
CN211
Replace the indoor electronic control P.C. board.
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
is black.
*2. Connect "+" of the multimeter to fan motor connector's
lead wire, and "-" to
resistance cannot be measured properly.
*3. Please replace the fuse after removing the indoor
terminal P.C. board from the electrical box.
Replace the fuse (F11) and the
No indoor fan motor. *3
Is the resistance of resistor
(R111) approximately 4 Ω?
Yes
Is there approximately 5 V DC
between 5 V (+) and GND (-) of the
indoor electronic control P.C. board?
Is there approximately 9 to 13 V DC
between 12 V (+) and GND (-) of the
indoor electronic control P.C. board?
No
Are connector CN10A on the
indoor electronic control P.C. board
or lead wires disconnected?
No
46
lead wire is red, whereas
lead wire, otherwise the
Replace the indoor power P.C.
board, the indoor terminal P.C.
No
board and the indoor fan motor.
Replace the indoor fan motor.
Yes
Connect the connector or repair
Yes
disconnection.