Troubleshooting - Mitsubishi SLZ-A09AR Technical & Service Manual

6

TROUBLESHOOTING

6-1. Cautions on troubleshooting
(1) Before troubleshooting, check the followings:
1Check the power supply voltage.
2Check the indoor/outdoor connecting wire for mis-wiring.
(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 turn
off the breaker.
2 When removing the indoor controller 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.
6-2. Trouble display
Blinking frequency of operation lamp shows the details of trouble of the indoor and the outdoor units.
(1) Incase of being indicated irregularity on the self diagnoses.
Blinking
Phenomenon
frequency
1 Mis-wiring
blinking
Indoor-outdoor
signal error
2 Pipe temperature thermistor
blinking / Liquid.
Room temperature
thermistor
Condenser / evaporator
temperature thermistor
Drain sensor
Operation lamp
Cause
Wiring between the indoor and
outdoor is coming off.
Difference of wiring polarity
between the indoor and outdoor.
Trouble of the outdoor inverter
P.C. board.
Trouble of the Indoor controller
board.
Mis-connecting of the pipe
temperature thermistor / Liquid.
Trouble of the pipe temperature
thermistor / Liquid.
Trouble of the Indoor controller
board.
Mis-connecting of the room
temperature thermistor.
Trouble of the room temperature
thermistor.
Trouble of the Indoor controller
board.
Mis-connecting of the condenser /
evaporator temperature thermistor.
Trouble of the condenser / evaporator
temperature thermistor.
Trouble of the Indoor controller
board.
Mis-connecting of the indoor drain
sensor
Trouble of the indoor drain sensor
Trouble of the Indoor controller
board.
Countermeasure
Check the wiring out between the indoor and
outdoor.
Check the outdoor inverter P.C. board. Refer to the
TECHNICAL & SERVICE MANUAL of outdoor unit.
Exchange the Indoor controller board.
Reinsert the connector (CN21).
Check the resistance value of the thermistor.
Exchange the Indoor controller board.
Reinsert the connector (CN20).
Check the resistance value of the thermistor.
Exchange the Indoor controller board.
Reinsert the connector (CN29).
Check the resistance value of the thermistor.
Exchange the Indoor controller board.
Reinsert the connector (CN31).
Check the resistance value of the thermistor.
Exchange the Indoor controller board.
To be continued on the next page.
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