Mitsubishi Electronics MS24WN Air Conditioner User Manual


 
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Replace the receiver P.C. board.
Replace the remote controller.
Replace the batteries.(Refer to page 27.)
Switch on the remote controller.
Repair or replace the indoor fan motor.
Resolder it.
Disconnect lead wires from connector CN211 on the indoor electronic control P.C. board.
Measure resistance between lead wires : No.1 and No.4 and then No.3 and No.4.
Turn OFF the power supply.
Check connector CN211 visually.
Reconnect the lead wires.
Yes
Yes
Check of indoor fan motor
A
Check of remote controller and receiver P.C. board
B
Are lead wires connected?
Is soldering point of the connector
correctly soldered?
Turn ON the power supply. Stop it if the unit operate.
Insert screwdriver into air outlet to rotate indoor fan
motor slowly for 1 revolution or over, and measure
voltage between No.2(+) and No.3(-) on CN121.
Is resistance 0 (short circuit) or (open circuit)?
Indoor unit operates by pressing the EMERGENCY OPERATION switch, but doesn’t operate with the remote controller.
Turn on a radio to AM and press switch 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?
Measure the voltage between receiver P.C. board connector CN301 No.1(+) and No.3(-) when remote
controller button is pressed.
Is the voltage approx. 4V DC?
Replace the indoor electronic control P.C.
board.
Reinstall the unit away from lights.
Attach a filter on receiving part.
Yes ( 0 or )
No
(others)
Yes
No
Yes
No
Is LCD display on the remote
controller displayed?
Remove the batteries, then set them back
and press the RESET button. Check if the
unit operates with the remote controller.
Yes
Does the unit operate with the
remote controller?
Yes
OK
No
(not clear)
Yes
No
No
No(5V or 0V DC)
No
wCheck if the remote controller is exclusive for this air conditioner.
Replace the indoor electronic control P.C. board.
Does voltage repeat 0V DC and 5V DC?
Yes
No
When OPERATION INDICATOR lamp flashes 3-time.
Indoor fan motor doesn’t operate.
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