Mitsubishi MCFH-13NV Service Manual page 46

Check of indoor fan motor
A
Indoor fan does not operate.
No
Are lead wires connected?
Reconnect the lead wires.
Disconnect lead wires from connector (Fan motor).
Measure resistance between lead wires No.1 and No.4 and then No.3 and No.4 of the fan motor.
Check of receiver P.C. board
B
Indoor unit operates by pressing the EMERGENCY OPERATION switch, but does not operate with the remote con-
troller.
Switch on the remote controller
Is LCD display on remote con-
troller visible?
Yes
Remove batteries and then set them back.
Check if the unit operates with remote
controller.
Does the unit operate with remote
controller?
Yes
OK
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.(see page 42.)
(not clear)
No
Turn on a radio to AM and press switch
on 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 No.2
when remote controller button is pressed.
Is the voltage approx. 4V DC ?
Replace the receiver.
Is soldered point normal?
Yes ( 0 or ∞ ) (others)
No
Yes
Yes
No
Yes
No(5V or 0V DC)
46
No
Yes
Resolder it.
Replace the indoor electronic control
P.C. board.
No
Replace the remote controller.
Re-install the unit away from lights.
Attach a filter on receiving part.
(+) and No.1
Replace the indoor electronic control
P.C. board.