Mitsubishi Electric MS-18NN Series, Service Manual

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10 TROUBLESHOOTING
10-1 Cautions on troubleshooting
10-1-1 Before troubleshooting, check the followings:
1) Check the power supply voltage.
2) Check the indoor/outdoor connecting wire for mis-wiring.
10-1-2 Take care the followings during servicing.
1) Be sure to unplug the power cord before removing the front panel, the cabinet, the top panel, and the P.C. boards.
2) When removing the P.C. board, hold the edge of the board with care NOT to apply stress on the components.
3) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
10-1-3 Troubleshooting procedure
1) First, check if the OPERATION INDICATION LAMP on the indoor unit is flashing to indicate an abnormality. To make
sure, check the abnormality indication for 2 or 3 times before starting service work.
2) If the P.C. board is supposed to be defective, check the copper foil pattern for disconnection and the components for
bursting and discoloration.
3) When troubleshooting, refer to the flow chart and the check table on page 25.
10-14 How to replace batteries
Weak batteries may cause the remote controller malfunction.
In this case, the remote controller can not be repaired only by the battery replacement. To operate the remote con-
troller normally, discharge the remote controller in the following order.
This remote controller has the reset button. After refilling new batteries, press the reset button with tip end of ball point
pen or the like, and then use the remote controller.
MS-18NN -
MS-24NN -
S1
S1
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