MITSUBISHI ELECTRIC MXZ-32SV - Manual (Page 25)

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12 TROUBLESHOOTING
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 page 123, 124 and the check table on page 125~127.
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 unplug the power cord before removing the front panel, the cabinet, the top panel, and the electronic con-
trol 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.
12-2. Instruction of troubleshooting
Operation start
Check the outdoor unit
LED indicator
A Check of power supply
on page 29.
• Indoor unit
serial signal
error
B Check of
serial signa
on page 29.
• Cool or HEAT
opereation only
C Check of
R.V.coil
on page 30.
• When cooling,
room does not
cool.
E Check of
inverter,
compressor
on page 31.
• When cooling, heat
exchanger of
non-operating indoor
unit frosts.
•When heating, non
operating indoor unit
gets warm.
D Check of LEV
on page 31.
• When cooling,
dew drops in the
non-operating
indoor unit
Check of mis-
piping. • When heating,
room doed not get
warm.
E Check of
inverter,compressor
on page 31.
Check mis-piping
Shortage of capacity
Refer to indicator list
on page 26, 27.
OFF
" 00 "
• 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.
Display other than " 00 "
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