Check Of Indoor Fan Motor - Mitsubishi Electric MS-18NN Series Service Manual

Check of indoor fan motor

A
Inodoor fan does not operate.
NO
Are lead wires connected?
Reconnect lead wires
Disconnect lead wires from connector CN211 on indoor control P.C. board.
Measure resistance between lead wires No.1 and No.4 and then No.3 and No.4.
Check of receiver P.C. board
B
Indoor unit operates by pressing the emergency ON/OFF switch, but does not operate with the remote controller.
Check the model name of 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 CN211 visually.
Yes
Is resistance 0 (short circuit) or ∞ (open circuit)?
Repair indoor fan motor.
No
Replace batteries.(see page 24.)
(not clear)
No
Turn 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 board connector No.2
when remote controller button is pressed.
Is the voltage approx. 4V DC?
No(5V or OV DC)
Replace the receiver
Is soldered point normal?
No
(others)
Yes ( 0 or ∞ )
No
Yes
Yes
NO
Yes
Resolder it.
Replace indoor electronic control
P.C. board.
Replace remote controller
Re-install the unit away from lights.
Attach a filter on receiving part.
(+) and No.1
Replace indoor electronic control
P.C. board.
27