Mitsubishi Electric MSC-A07WV-E1 Service Manual page 112

When OPERATION INDICATOR lamp flashes 3-time.
Indoor fan motor doesn't operate.
A A Check of indoor fan motor
Turn OFF the power supply.
Check connector CN211 visually.
No
Reconnect the lead wires.
Disconnect lead wires from connector CN211 on indoor electronic control P.C. board.
Measure resistance between lead wires No.1 and No.5 and then No.3 and No.5.
Is resistance 0 (short circuit) or ∞ (open circuit)?
Repair or replace the indoor fan motor.
Indoor unit operates by pressing the EMERGENCY OPERATION switch, but doesn't operate with the remote controller.
B B Check of remote controller and receiver P.C. board
wCheck the remote controller is exclusive for this air conditioner.
Switch on the remote controller.
Is LCD display on the remote con-
troller displayed?
Yes
Remove batteries, then set them back and press the RESET
button. Check if the unit operates with the remote controller.
Does the unit operate with the
remote controller?
Yes
OK
All manuals and user guides at all-guides.com
Yes
Are lead wires connected?
Yes
Yes ( 0 or ∞ )
No
Replace the batteries. (Refer to page 104.)
(not clear)
No Turn on a radio to AM and press switch
on the remote controller.
Is noise heard from radio?
Yes
Are there any fluorescent lights of
inverter or rapid-start type within
the range of 1m?
No
Measure the voltage between receiver P.C. board connector CN302
(+)
(–)
No.3 and No.5 when the remote controller button is pressed.
Is the voltage approx. 4V DC?
No(5V or 0V DC)
Replace the receiver P.C. board.
112
Is soldered point of the
connector correctly soldered?
Turn ON the power supply. Stop it if the unit operates.
Insert screwdriver into air outlet to rotate indoor fan
motor slowly for 1 revolution or over, and measure volt-
No
age No.2(+) and No.3(-) on CN121.
(others)
No
Does voltage repeat 0V DC and 5V DC?
Replace the indoor electronic control P.C. board.
No
Yes
• Reinstall the unit away from lights.
• Attach a filter on receiving part.
Yes
Replace the indoor electronic control
P.C. board.
No
Resolder it.
Yes
Replace the remote controller.