Replace The Indoor Power P.c; Board; Yes; 12 Seconds After The Emergency - Mitsubishi Electric MSZ-EF18VGW-E1 Service Manual

10-6. TROUBLESHOOTING FLOW
A Check of indoor fan motor
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 325 V DC
between CN211
and (-) ?
No
Replace the indoor power
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.

OBH831D
Pay enough attention to the high voltage on the fan motor connector CN211.
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 emer-
gency 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 CN102
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 CN102
(+) and JPG (GND)(-)/CN102
(-)* on the indoor electronic control
P.C. board fall to 2 V or less within
Yes
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
(+) and JPG(GND)(-).
Yes
No
No
* JPG: MSZ-EF·VG-
CN102
Measure the voltage CN102
and JPG (GND)(-)/CN102
on the indoor electronic control
No
P.C. board when the fan motor is
(Changed)
rotating.
Yes
(Unchanged)
Replace the indoor elec-
tronic control P.C. board.
No
(Changed)
37
(-).
(-).
Replace the indoor fan motor.
Replace the indoor electronic
control P.C. board.
,
E1 ET1
: MSZ-EF·VG- , ,
E2 ET2 ET3
MSZ-EF-VGK- , , ,
E1 ET1 ER1
(+)
(-)*
, ,
E2 ET2 ER2