Mitsubishi Electric MCFH-GA35VB Service Manual page 15

9-5. Troubleshooting flow
Indoor fan does not operate.
Check of indoor fan motor
A
No
Are lead wires connected?
Reconnect the lead wires.
Disconnect lead wires from connector (Indoor fan motor).
Measure resistance between lead wires No.1 and No.4 and then No.3 and No.4 of the indoor fan
motor.
Indoor unit operates by pressing the EMERGENCY OPERATION switch, but does not operate with the remote con-
troller.
Check of remote controller and receiver P.C. board
B
w Check if the remote controller is exclusive for this air conditioner.
Switch on the remote controller.
Is LCD display on remote
controller visible?
Yes
Remove the batteries, then set them back
and press the RESET button. Check if the
unit operates with the remote controller.
Does the unit operate with remote
controller?
Yes
OK
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Turn OFF power supply.
Check connector (Fan motor) visually.
Yes
Is resistance 0 (short circuit) or ∞ (open circuit)?
Replace the indoor fan motor.
No
Replace the batteries.(Refer to 9-4.)
(not clear)
No
Turn on a radio to AM and press switch
on 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 CN101 No.2
when remote controller button is pressed.
Is the voltage approx. 4V DC ?
No(5V or 0V DC)
Replace the receiver P.C. board.
15
Is soldered point of the connector
correctly soldered?
Replace the indoor electronic control
P.C. board.
No
Yes ( 0 or ∞ ) (others)
No
Yes
Yes
Replace the indoor electronic control
P.C. board.
No
Yes
Resolder it.
Replace the remote controller.
Reinstall the unit away from lights.
Attach a filter on receiving part.
+ and No.1
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