125
13-3. troubleshooting check table <INDOOR UNIT>
lighting
not lighting
Operation
Indicator
❈
Before taking measures, make sure that the symptom reappears, for accurate troubleshooting.
Self check table
NO.
1
2
3
4
Abnormal
point
Mis-wiring
Serial
signal
Indoor coil
thermistor
Room
tempera-
ture ther-
mistor
Indoor fan
motor
Defrost
thermistor
Indication
0.5-second ON
0.5-second OFF
1-time flash
2.5-second OFF
2-time flash
2.5-second OFF
3-time flash
2.5-second OFF
6-time flash
2.5-second OFF
Symptom
Outdoor unit
does not run.
Outdoor unit
does not run.
Indoor fan motor
repeats 12 sec-
onds ON and 3
minutes OFF.
When the indoor
fan motor
breaks, the fan
keeps stopping.
Outdoor unit
does not run
Detect method
When serial signal stops for 4
to 5 seconds after 1st on of
52C relay by POWER turning
on.
When serial signal from out-
door unit stops for 4 to 5 sec-
onds.
Detect Indoor coil/room tem-
perature thermistor short or
open circuit every 8 seconds
during operation.
When rotational frequency
feedback pulse signal is not
emit during 12-second indoor
fan operation.
When the defrost thermistor
shorts or opens after the com-
pressor start-up.
Check point
●
Check switch SW2-
2
.(MU type or MUH
type)
●
Check wiring (visual check and conductiv-
ity check).
●
Check indoor electronic control
P.C.board.
●
Check outdoor DEICER P.C. board.
●
Check electrical parts.
●
Check resistance of thermistor.
●
Reconnect connector.
●
Check indoor electronic control P.C.board.
●
Disconnect connector CN211 and then
check connector CN121 - to make
sure rotational frequency feedback signal
of 1.5V or over exists.
●
Check indoor electronic control P.C.
board.
●
Check indoor fan motor.
●
Reconnect connector.
●
Check outdoor DEICER P.C. board.(MUH)
●
Check outdoor control P.C. board. (MXZ)
●
Check resistance of thermistor.
●
Reconnect connector.
2
3
5
Out door
control
system
error
7-time flash
2.5-second OFF
Outdoor unit
does not run
●
Check outdoor control P.C. board.
Outdoor
power
system
5-time flash
2.5-second OFF
Out door
refriger-
ant
system
error
7
6
Outdoor unit
does not run
When compressor has
stopped due to over current
protection or start-up failure
protection 3 times in a row
within 1 min. after start-up.
●
Check inverter and compressor.
10-time flash
2.5-second OFF
Outdoor unit
does not run
●
Amount of gas.
●
Outdoor control P. C. board.
●
Contact of LEV board connectors.
When the compressor opera-
tion has been interrupted by
LEV protection continuously 5
times, the compressor stops
operation.