Troubleshooting Flow - Mitsubishi Electric MSZ-FD25VA Service Manual

10-6. TROUBLESHOOTING FLOW

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.
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 VDC between
CN211 1 (+) and 3 (-), and does
the voltage between CN211 5(+)
and 3(-) rise to the range of 3 to 6
VDC 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.
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 after
No
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. w
1.Measure the voltage between CN211 1(+) and 3(-).
2.Measure the voltage between CN211 5(+) and 3(-).
wIf more than 12 seconds passes after EMERGENCY OPERATION switch
is pressed, the voltage mentioned above 2 goes 0 VDC although the
indoor electric control P.C. board is normal.
Yes
Replace the indoor fan motor.
No
Is it unchanged holding
0 or 15 VDC?
Replace the indoor fan motor.
No
(Changed)
Replace the indoor electronic control P.C. board.
Yes
(Unchanged)
28
CN211
Indoor electronic
control P.C. board