Mitsubishi Electric MSZ-HR25VFK-ER1 Service Manual page 31

HR60/71
The indoor fan motor error has occurred, and the indoor fan does not operate.
Turn OFF the power supply.
Is there any foreign matter that interferes
the rotation of the line flow fan?
Yes
Remove the foreign matter and
adjust the line flow fan.
The indoor fan motor error has occurred, and the indoor fan repeats "12-second ON and 30-second OFF" 3 times, and then stops.
Measure the voltage between CN211
(+) and (–) while the fan motor is
rotating.
B Check of remote controller and indoor electronic control P.C. board
Check if the remote controller is exclusive for this air conditioner.
Press OFF/ON (stop/operate) 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
OBH822F
Pay enough attention to the high voltage on the fan motor connector CN211.
Turn ON the power supply, wait 5 seconds or more, and then press the
emergency operation switch.
Measure the supply voltage as follows within 12 seconds after the emer-
gency operation switch is pressed.
If more than 12 seconds passes, turn OFF the power supply and turn it
No
ON again, then measure the voltage. *
<Indoor power P.C. board>
1. Measure the voltage between CN211
2. Measure the voltage between CN211
Does the voltage between CN211
(+) and
P.C. board rise to the range of 3 to 6
V DC within 12 seconds after the
emergency operation switch is
pressed?
Replace the indoor fan motor.
Is it unchanged holding 0
or 15 V DC?
Yes
(Unchanged)
Replace the indoor fan motor.
Replace the batteries. (Refer to 10-1.4.)
No
(Not clear)
Turn ON a radio to AM and press OFF/ON
(stop/operate) button on the remote con-
No
troller. *1
Is noise heard from radio?
Yes
Are there any fluorescent 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)
(+) and (–).
(+) and (–).
Is there 325 V DC
between CN211 (+)
No
and (–) ?
Yes
(–) on the indoor power
Yes
Replace the indoor power P.C. board.
No
(Changed)
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 OFF/
ON (stop/operate) button on the remote controller is
pressed. However, it may be difficult to see the illumi-
nated LED of the signal transmitting section with a
smartphone camera.
* 2 If the inverter fluorescent light is turned on when the
room is cool, the unit may have difficulty receiving the
signal from the remote controller or may not be able to
operate with it; if the inverter fluorescent light is turned
on when the room is warm, the unit may be able to
operate with the remote controller.
No
Yes
31
If more than 12 seconds
*
passes after the emergency
operation switch is pressed,
the voltage measured at 2.
above goes 0 V DC although
the indoor P.C. board is
normal.
Replace the indoor power P.C. board.
Replace the indoor power P.C. board.
No
Replace the remote controller.
• Reinstall the unit away from lights.
• Attach a filter on receiving part.