Service manual

51
Check of outdoor thermistors
J
When OPERATION INDICATOR lamp flashes 6-time.
The thermistors in the outdoor unit are abnormal.
Check of indoor electronic control P.C. board
I
Check the both “parts side” and “pattern
side” of indoor electronic control P.C.
board visually.
Replace the fuse.
Is fuse(F11) blown?
Be sure to check both fuse
and varistor in any case.
Replace the fan
motor.
Replace the indoor
electronic control
P.C. board.
Is winding
resistance of
fan motor 0 "?
Is winding
resistance of
vane motor 0 "?
No
Yes
Replace the vane
motor.
No
Yes
Yes
Is varistor(NR11) burnt?
Replace the varistor.
Yes
Turn OFF the power supply.
Disconnect indoor fan motor connector CN211(MSZ09UN)
and vane motor connector CN151 from the indoor
electronic control P.C. board and turn ON the power supply.
No
No
Does the unit operate with the remote controller or
the OPERATION INDICATOR lamp light up
by pressing the EMERGENCY OPERATION switch?
Yes
No
Be sure to check both resistances.
Turn OFF the
power supply.
Turn OFF the
power supply.
Measure
resistance
between CN
6411 and 2.
Measure
resistance
between CN
6421 and 2.
No
Yes
Replace the
thermistor.
Replace the outdoor
electronic control
P.C. board.
Disconnect the connectors CN641 and CN642 from the outdoor electronic control P.C. board.
Check the characteristics of each thermistor.
1 Connect CN641 and
CN642.
2 Disconnect the
connector between
the compressor and
IPM.
Measure
resistance
between CN
6413 and 4.
Turn ON the
power supply to
indoor unit and
press the
EMERGENCY
OPERATION
switch.
Discharge
temperature
thermistor
RT62
()
Fin
temperature
thermistor
RT64
(
)
Does the
resistance of the
thermistor have
the characteristics
on page 45?
No
Yes
Does the unit
operate 10 minutes
or more?
Is LED in the
outdoor electronic
control P.C. board
flashing 5 minutes?
Reconnect the
connector.
Yes
No
Defrost
thermistor
RT61
()
The unit doesn’t operate with the remote controller.
Also, the OPERATION INDICATOR lamp doesn’t light up by pressing the EMERGENCY OPERATION switch.
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