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52
TROUBLESHOOTING
12
Operation start
Check the outdoor unit
LED indicator.
A
Check of power supply
See page 58.
• Indoor unit
serial signal
error
B
Check of
serial signal
See page 59.
• COOL or
HEAT
operation only
C
Check of
R.V.coil
See page 60.
• When cooling,
room does not
cool.
E
Check of
inverter,
compressor
See page
62 or 63.
• When cooling, heat
exchanger of
non-operating indoor
unit frosts.
•When heating, non-
operating indoor unit
gets warm.
D
Check of LEV
See page 61.
• When cooling,
dew drops in the
non-operating
indoor unit.
Check of mis-
piping
• When heating,
room does not get
warm.
E
Check of
inverter, compressor
See page 62 or 63.
Check mis-piping,
shortage of capacity
Refer to indicator list
on page 53,54,55 and
56.
OFF
Both LED 1 and
LED 2 lighting
LED 1 or LED 2
has blinked.
MXZ-A18WV -
MXZ-A26WV -
MXZ-A32WV -
E1
E1
E1
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 abnormality indication is flashing on and off before starting service work.
2) If the electronic control 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 on this page and the check table on page 53, 54, 55 and 56.
Lead wiring
Housing point
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 mis-wiring.
2. Take care the following during servicing.
1) Before servicing the air conditioner, be sure to first turn off the remote controller to stop the unit, and then after con-
firming 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.
MXZ-A18WV-
MXZ-A26WV-
MXZ-A32WV-
E1
E1
E1
12-2. Instruction of troubleshooting
• Check the indoor unit with referring to the indoor unit service manual, and confirm that there is any problem in the indoor
unit.
Then, check the outdoor unit with referring to this page.
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