Troubleshooting - Mitsubishi Electric MSZ-LN-VG Series Service Manual

TROUBLESHOOTING

12
MXZ-2F33VF MXZ-2F42VF
MXZ-2F33VF2 MXZ-2F42VF2 MXZ-2F53VF2 MXZ-2F53VFH2
MXZ-2F33VF3 MXZ-2F42VF3 MXZ-2F53VF3 MXZ-2F53VFH3
MXZ-3F54VF MXZ-3F68VF
MXZ-3F54VF2 MXZ-3F68VF2 MXZ-4F72VF2 MXZ-4F80VF2
MXZ-3F54VF3 MXZ-3F68VF3 MXZ-4F72VF3 MXZ-4F80VF3
12-1. 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 first with the remote controller, and 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 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 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 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 12-2, 12-3 and 12-4.
12-2. 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 (12-4.) 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.
OBH790D
MXZ-2F53VF MXZ-2F53VFH
MXZ-4F72VF
<Incorrect>
<Correct>
Lead wiring
Connector housing
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