Mitsubishi Electric Mr. Slim MSZ-FE09NA Service Manual page 28

B Check of remote controller and indoor electronic control P.C. board
Check if the remote controller is exclusive for this air conditioner.
MSZ-FE09NA MSZ-FE12NA
Press OPERATE/STOP (ON/OFF)
button on the remote controller.
Is LCD display on the remote controller
visible?
Yes
Remove the batteries, then set them back
and press RESET button. (Refer to 9-1.4.)
Check if the unit operates with the remote
controller.
Does the unit operate with the remote
controller?
Yes
OK
MSZ-FE18NA
Press OPERATE/STOP (ON/OFF)
button on the remote controller.
Is LCD display on the remote controller
visible?
Yes
Remove the batteries, then set them back
and press RESET button. (Refer to 9-1.4.)
Check if the unit operates with the remote
controller.
Does the unit operate with the remote
controller?
Yes
OK
Replace the batteries. (Refer to 9-1.4.)
No
(Not clear)
Turn ON a radio to AM and press OP-
ERATE/STOP (ON/OFF) button on the
No
remote controller.
Is noise heard from radio?
Yes
Are there any fl uorescent lights of
inverter or rapid-start type within the
range of 3.28 ft.?
No
Replace the indoor electronic control
P.C. board. (Including the receiver)
Replace the batteries. (Refer to 9-1.4.)
No
(Not clear)
Turn ON a radio to AM and press OP-
ERATE/STOP (ON/OFF) button on the
No
remote controller.
Is noise heard from radio?
Yes
Are there any fl uorescent lights of
inverter or rapid-start type within the
range of 3.28 ft.?
No
Measure the voltage between power
monitor receiver SW P.C. board connec-
tor CN20A No.2(+) and No.3(-) when the
remote controller button is pressed.
Is the voltage approximate 4 VDC?
No
Replace power monitor receiver SW P.C. board.
No
Yes
No
Yes
Yes
28
Replace the remote controller.
• Reinstall the unit away from lights.
• Attach a fi lter on receiving part.
Replace the remote controller.
• Reinstall the unit away from lights.
• Attach a fi lter on receiving part.
Replace indoor electronic control P.C.
board.