Troubleshooting Flow - Mitsubishi Electric MSZ-GC22VA Service Manual

10-6. Troubleshooting flow

When OPERATION INDICATOR lamp flashes 3-time. Indoor fan does not operate.
Check of indoor fan motor
A
No
Reconnect the lead wires.
Disconnect the lead wires from connector CN211 on indoor power P.C. board.
Measure the resistance between lead wires No.1 and No.4 and then No.4 and No.7.
Is the resistance 0 (short circuit) or ∞ (open circuit)?
Indoor terminal
P.C.board
Fuse (F11)
Indoor unit operates by pressing EMERGENCY OPERATION switch, but does not operate with the remote controller.
Check of remote controller and indoor electronic control P.C. board
B
wCheck if the remote controller is exclusive for this air conditioner.
Press OPERATE/STOP(ON/OFF) button on the remote controller.
Is LCD display on the the remote
controller visible?
Yes
Remove the batteries, then set them back
and press RESET button. (Refer to 10-
1.4.) Check if the unit operates with the
remote controller.
Does the unit operate with the
remote controller?
Yes
OK
Turn OFF the power supply.
Check connector CN211 visually.
Are lead wires connected?
Yes ( 0 or ∞ )
Replace the indoor fan motor.
Indoor power P.C.board
CN121
Varistor
(NR11)
No
Replace the batteries. (Refer to 10-1.4.)
(not clear)
No
Turn ON a radio to AM and press
OPERATE/STOP(ON/OFF) button on the remote controller.
Is noise heard from radio?
Are there any fluorescent lights of
inverter or rapid-start type within
the range of 1m?
Replace the indoor electronic
control P.C. board.
(including the receiver)
Yes Are soldered points of the
connector correctly soldered to
indoor power P.C. board?
Yes
Turn ON the power supply. Rotate indoor fan slowly for 1 revo-
lution or over with a screwdriver etc. from air outlet, and mea-
No
sure the voltage No.2(+) and No.1(-) on CN121.
(others)
No
Does the voltage repeat 0V DC and 5V DC?
Replace the indoor power / terminal P.C. board
and the indoor electronic control P.C. board.
CN211
No
Yes
Yes
No
20
No
Resolder it.
Yes
Replace the remote controller.
● Reinstall the unit away from lights.
● Attach a filter on receiving part.