Troubleshooting Flow - Mitsubishi Electric MSZ-GS06NA - U1 Service Manual

9-6. TROUBLESHOOTING FLOW

A Check of indoor fan motor
MSZ-GS06/09/12/15/18NA
MSY-GS09/12/15/18NA
The indoor fan motor error has occurred, and the indoor fan does not operate.
Turn OFF the power supply.
Is there any foreign matter that interferes
the rotation of the line flow fan?
Yes
Remove the foreign matter and
adjust the line flow fan.
Is there 294/325 V DC
between CN211
and (–) ?
No
Replace the indoor power
P.C. board and the indoor
terminal P.C. board.
The indoor fan motor error has occurred, and the indoor fan repeats "12-second ON and 30-second OFF" 3 times, and then stops.
Measure the voltage between CN211
(+) and (–) while the fan motor is
rotating.
Replace the indoor power P.C.
board and the indoor terminal P.C.
board (MSZ-GS06/09/12/15NA).
Replace the indoor power P.C.
board (MSZ-GS18NA).
OBH874A
Pay enough attention to the high voltage on the fan motor connector.
Turn ON the power supply, wait 5 seconds or more, and then press the
emergency operation switch.
Measure the supply voltage as follows within 12 seconds after the
emergency operation switch is pressed.
If more than 12 seconds passes, turn OFF the power supply and turn it
ON again, then measure the voltage. *
No
<Indoor power P.C. board>
1. Measure the voltage between CN211
2. Measure the voltage between CN211
<Indoor electronic control P.C. board>
3. Measure the voltage between CN10A (+) (MSZ-GS06/09/12/15NA)/
(+) (MSZ-GS18NA) and GND(–).
* If more than 12 seconds passes after the emergency operation switch is
pressed, the voltage measured at 2. above goes 0 V DC although the
indoor P.C. board is normal.
Does the voltage between CN211
(+) and (–) on the power P.C. board
(+) rise to the range of 3 to 6 V DC within
Yes
12 seconds after the emergency
operation switch is pressed?
Does the voltage between CN10A
(+) (MSZ-GS06/09/12/15NA)/
(MSZ-GS18NA) and GND(–) on the
indoor electronic control P.C. board
Yes
fall to 2 V or less within 12 seconds
after the emergency operation switch
is pressed?
Is it unchanged holding 0
or 15 V DC?
Replace the indoor fan motor.
Is it unchanged holding 0
or 5 V DC?
Yes
(Unchanged)
(+) and
(+) and
Yes
No
(+)
No
Measure the voltage CN10A (+) (MSZ-
GS06/09/12/15NA)/
No
and GND(–) on the indoor electronic control
(Changed)
P.C. board when the fan motor is rotating.
Yes
(Unchanged)
Replace the indoor electronic
control P.C. board.
No
(Changed)
41
(–).
(–).
Replace the indoor fan motor.
Replace the indoor electronic
control P.C. board.
(MSZ-GS18NA) (+)