Troubleshooting - Mitsubishi Electric MS-A18VD-K1 Service Manual

8

TROUBLESHOOTING

MS-A18VD
MS-A24VD
MS-A30VD
8-1. Cautions on troubleshooting
1. Before troubleshooting, check the following:
1) Check the power supply voltage.
2) Check the indoor/outdoor connecting wire for mis-wiring.
2. Take care the following during servicing.
1) Before servicing the air conditioner, be sure to turn off the unit first with the remote controller, and then after confirm-
ing 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 electronic
control P.C. board.
3) When removing the electronic control 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 housing of the connector. DO NOT pull the lead wires.
3. Troubleshooting procedure
1) First, check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality.
To make sure, check how many times the OPERATION INDICATOR lamp is flashing on and off before starting service
work.
2) Before servicing 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 discolouration.
4) When troubleshooting, refer to 8-2. and 8-3.
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.
1 Remove the front lid and insert batteries.
Then reattach the front lid.
NOTE: 1. If the RESET button is not pressed, the remote controller may not operate correctly.
2. Do not use the leaking batteries.
OB400C
<Incorrect>
Lead wiring
Insert the negative pole
of the batteries first.
Check if the polarity of
the batteries is correct.
<Correct>
Housing point
2 Press the RESET button with a thin instrument,
and then use the remote controller.
RESET button
12