Troubleshooting Flow - Mitsubishi MSZ-FA25VA Service Manual

9-6. Troubleshooting flow

When POWER lamp flashes 3-time.
Indoor fan does not operate.
Check of indoor fan motor
A
The indoor fan motor error has occurred, and the indoor fan doesn't operate.
Turn OFF the power supply.
Insert a stick such as a screw driver
into the air outlet, and check if there is
any catch in the rotation of the line
flow fan.
Is there any foreign matter that
interferes the rotation of the
line flow fan?
Yes
Adjust the line flow fan and
remove the foreign matter.
Is there 311V DC between
CN211 1 (+) and 3 (-), and does
the voltage between CN211 5(+)
and 3(-) rise to the range of 3 to 6V
DC within 12 seconds after
EMERGENCY OPERATION switch
is pressed?
Replace the indoor electronic control 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
6(+) and 3(-) while the fan
motor is rotating.
Pay careful attention to the high voltage on
the fan motor connector CN211.
w
Turn ON the power supply, wait 5 seconds or more, and then press
EMERGENCY OPERATION switch.
Measure the supply voltage as follows within 12 seconds
No
after EMERGENCY OPERATION switch is pressed.
If more than 12 seconds passes by, turn OFF the power supply and
turn ON it again, then measure the voltage.
1.Measure the voltage between CN211 1(+) and 3(-).
2.Measure the voltage between CN211 5(+) and 3(-).
wIf 12 seconds or more passes after EMERGENCY OPERATION switch
is pressed, the voltage mentioned above 2 goes 0V DC although the
indoor electric control P.C. board is normal.
Yes
Replace the indoor fan motor.
No
Is it unchanged holding
0V DC or 15V DC?
Replace the indoor fan motor.
Changed
Replace the indoor electronic control P.C. board.
Unchanged
21
CN211
Indoor electronic
control P.C. board