Troubleshooting - Mitsubishi Electric MSZ-EF VE Series Service Manual

11

TROUBLESHOOTING

MXZ-2D33VA MXZ-2D40VA MXZ-2D42VA MXZ-2D53VA MXZ-2D53VAH
MXZ-3D54VA MXZ-3D54VA2 MXZ-3D68VA MXZ-4D72VA MXZ-4D83VA
11-1. 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 unit fi rst with the remote controller, and after confi rming
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 electrical parts, be careful of the residual voltage of smoothing capacitor.
4) When removing the P.C. board, hold the edge of the board with care NOT to apply stress on the components.
5) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
3. Troubleshooting procedure
1) Check if the OPERATION INDICATOR lamp on the indoor unit is fl ashing on and off to indicate an abnormality. To
make sure, check how many times the OPERATION INDICATOR lamp is fl ashing on and off before starting service
work.
2) Before servicing, check that the connector and terminal are connected properly.
3) When the P.C. board seems to be defective, check the copper foil pattern for disconnection and the components for
bursting and discoloration.
4) Refer to 11-2, 11-3 and 11-4.
11-2. FAILURE MODE RECALL FUNCTION
This air conditioner can memorize the abnormal condition which has occurred once.
Even though LED indication listed on the troubleshooting check table (11-4.) disappears, the memorized failure details
can be recalled.
1. Flow chart of failure mode recall function for the indoor/outdoor unit
Refer to the service manual of indoor unit.
OBH626E
<Incorrect>
<Correct>
Lead wiring
Housing point
86
MXZ-5D102VA