Troubleshooting - Mitsubishi Electric MSZ-EF18VGW-E1 Service Manual

10

TROUBLESHOOTING

MSZ-EF18VGW MSZ-EF22VGW MSZ-EF25VGW MSZ-EF35VGW MSZ-EF42VGW MSZ-EF50VGW
MSZ-EF18VGB MSZ-EF22VGB
MSZ-EF18VGS MSZ-EF22VGS
MSZ-EF18VGKW MSZ-EF22VGKW MSZ-EF25VGKW MSZ-EF35VGKW MSZ-EF42VGKW MSZ-EF50VGKW
MSZ-EF18VGKB MSZ-EF22VGKB MSZ-EF25VGKB MSZ-EF35VGKB MSZ-EF42VGKB MSZ-EF50VGKB
MSZ-EF18VGKS MSZ-EF22VGKS MSZ-EF25VGKS MSZ-EF35VGKS MSZ-EF42VGKS MSZ-EF50VGKS
10-1. CAUTIONS ON TROUBLESHOOTING
1. Before troubleshooting, check the following
1) Check the power supply voltage.
2) Check the indoor/outdoor connecting wire for miswiring.
2. Take care of the following during servicing
1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, and then after
confirming the horizontal vane is closed, turn OFF the breaker and/or disconnect the power plug.
2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the P.C. board.
3) When removing the P.C. board, hold the edge of the board with care NOT to apply stress on the components.
4) When connecting or disconnecting the connectors, hold the connector housing. DO NOT pull the lead wires.
3. Troubleshooting procedure
1) Check if the OPERATION INDICATOR lamp on the indoor unit is blinking ON and OFF to indicate an abnormality.
To make sure, check how many times the OPERATION INDICATOR lamp is blinking ON and OFF before starting ser-
vice work.
2) Before servicing, check that the connector and terminal are connected properly.
3) When the electronic control P.C. board seems to be defective, check the copper foil pattern for disconnection and the
components for bursting and discoloration.
4) When troubleshooting, Refer to 10-2, 10-3 and 10-4.
4. How to replace batteries
Weak batteries may cause the remote controller malfunction.
In this case, replace the batteries to operate the remote controller normally.
Remove the front lid and insert batteries.
Then reattach the front lid.
NOTE: 1. If RESET button is not pressed, the remote controller may not operate correctly.
2. This remote controller has a circuit to automatically reset the microprocessor when batteries are replaced.
This function is equipped to prevent the microprocessor from malfunctioning due to the voltage drop caused by the
battery replacement.
3. Do not use the leaking batteries.
OBH831D
MSZ-EF25VGB
MSZ-EF25VGS
<Incorrect>
Lead wiring
Insert the negative pole of the
batteries first. Check if the polarity
of the batteries is correct.
MSZ-EF35VGB MSZ-EF42VGB
MSZ-EF35VGS MSZ-EF42VGS
<Correct>
Connector housing
Press RESET button with a thin instrument, and
then use the remote controller.
30
MSZ-EF50VGB
MSZ-EF50VGS
RESET button