39
TROUBLESHOOTING
11
11.1
Cautions on troubleshooting
11.1.1
Before troubleshooting, check the followings :
1) Check the power supply voltage.
2) Check the indoor / outdoor connecting wire for mis-wiring.
11.1.2
Take care the followings during servicing.
1) Before servicing the air conditioner,be sure to first turn off the remote controller to stop the main unit,and then after
confirming the horizontal vane is closed,turn off the breaker.
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.
11.1.3
Troubleshootina procedure
1) First, check if the POWER 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 supposend 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 .
11-2
Troubleshooting procedure
The indoor unit will
not respond to the
remote controller.
The operation indicator
(on the left-hand
side) is blinking
Operation start
Remote controller
and receiver board.
Causes in the indoor/outdoor unit
• Incorrect wiring
• Serial signal error
Serial signal
(Page 42)
See note 1
NOTE1:In case of serial signal
error, the mis-wiring
indication will apper by
turning the power off and
turning it back on.
NOTE2:Enclosed by the
broken line are the indoor
unit related parts.
Inverter
Compressor
A to E
Compressor
See page 44,45.
• Check the indoor/
outdoor connecting
wiring.
• Check the outdoor
power supply.
• Pipe temperature
thermistor
• Room temperature
thermistor
Indoor fan
motor
Causes in the indoor unit.
• Indoor fan motor abnormality.
Pipe temperature thermistor
abnormality.
• Room temperature thermistor
abnormality.
Single blink
The indoor unit will not respond to the remote
controller. In addition, the operation
indicator (on the left-hand side)will not
blink even if the emergency run switch is
pressed.
Indoor controller
board
Six blinks
Two blinks
2.5 second OFF
2.5 second OFF
Seven blinks
2.5 second OFF
2.5 second OFF
Three blinks
A to E
Transistor module
See page 44,45.
F Outdoor
thermistor
See page 46.
Causes in the outdoor unit
• Outdoor thermistor
abnormality.
Causes in the outdoor unit
• Outdoor control
system error
G 4-way
value coil.
See page 46.
• High
pressure
switch
Only
MXZ-32NV
• Low
pressure
switch
• Compressor
thermostat
Linear
expansion
valve
H Outdoor fan
motor.
See page 47.
J Power supply
See page 47.
Outdoor
board