Mitsubishi Electric MSZ-DM25VA Service Manual page 23

B Check of remote controller and indoor electronic control P.C. board
Check if the remote controller is exclusive for this air conditioner.
Press STOP/OPERATE/ (OFF/ON)
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 10-1.4.)
Check if the unit operates with the remote
controller.
Does the unit operate with the remote
controller?
Yes
OK
OBH750
Replace the batteries. (Refer to 10-1.4.)
No
(Not clear)
Turn ON a radio to AM and press STOP/
OPERATE/ (OFF/ON) button on the
No
remote controller. 1
Is noise heard from radio?
Yes
Are there any f uorescent lights of
inverter or rapid-start type within the
range of 1 m? 2
No
Replace the indoor electronic control
P.C. board. (Including the receiver)
1 Look at the image of the signal transmitting section of
the remote controller through the monitor of a digital
camera or a camera phone. It is normal if the LED of
the signal transmitting section lights up when the STOP/
OPERATE/ (OFF/ON) button on the remote control-
ler is pressed. However, it may be diff cult to see the
illuminated LED of the signal transmitting section with a
smartphone camera.
2 If the inverter f uorescent light is turned on when the
room is cool, the unit may have diff culty receiving the
signal from the remote controller or may not be able to
operate with it; if the inverter f uorescent light is turned
on when the room is warm, the unit may be able to
operate with the remote controller.
No
Yes
23
Replace the remote controller.
• Reinstall the unit away from lights.
• Attach a f lter on receiving part.