Troubleshooting Check Table - Mitsubishi Electric MSZ-D30NA Service Manual

9-4. TROUBLESHOOTING CHECK TABLE

Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
When the indoor unit has started operation and the following detection method has detected an abnormality (the first detection
after the power ON), the indoor electronic control P.C. board turns OFF the indoor fan motor with OPERATION INDICATOR
lamp flashing.
OPERATION INDICATOR
Abnormal
No. Operation indicator lamp
point
Left lamp fl ashes.
0.5-second ON
1 Miswiring or
serial signal
0.5-second OFF
Left lamp fl ashes.
Indoor coil
2-time flash
thermistor
2
2.5-second OFF
Room
temperature
thermistor
Left lamp fl ashes.
3-time flash
Indoor fan
3
motor
2.5-second OFF
Left lamp fl ashes.
4-time flash
Indoor con-
4
trol system
Left lamp fl ashes.
5-time flash
Outdoor
5 power sys-
tem
Left lamp fl ashes.
6-time flash
6 Outdoor
thermistors
Left lamp fl ashes.
7-time flash
7 Outdoor con-
trol system
Left lamp fl ashes.
14-time flash
Other abnor-
8
mality
2.5-second OFF
Lighted
Blinking
Not lighted
2.5-second OFF
2.5-second OFF
2.5-second OFF
2.5-second OFF
Symptom Condition
Indoor unit
and outdoor The serial signal from the outdoor unit is not
unit do not received for a maximum of 6 minutes.
operate.
Indoor unit
and outdoor The indoor coil or the room temperature
unit do not thermistor is short or open circuit.
operate.
Indoor unit
and outdoor The rotational frequency feedback signal is not
unit do not emitted during the indoor fan operation.
operate.
Indoor unit
It cannot properly read data in the nonvolatile
and outdoor
memory of the indoor electronic control P.C.
unit do not
board.
operate.
Indoor unit It consecutively occurs 3 times that the
and outdoor compressor stops for overcurrent protection or
unit do not start-up failure protection within 1 minute after
operate. start-up.
Indoor unit
and outdoor The outdoor thermistors short or open circuit
unit do not during the compressor operation.
operate.
Indoor unit
It cannot properly read data in the nonvola-
and outdoor
tile memory of the inverter P.C. board or the
unit do not
outdoor electronic control P.C. board.
operate.
Indoor unit
and outdoor An abnormality other than above mentioned is
unit do not detected.
operate.
23 23
Correspondence
• Refer to 9-6. "How to check miswiring
and serial signal error".
• Refer to 9-7.the characteristics of indoor
coil thermistor, and the room tempera-
ture thermistor.
• Refer to 9-6. "Check of indoor fan mo-
tor".
• Replace the indoor electronic control
P.C. board.
• Refer to "How to check of inverter/
compressor".
Refer to outdoor unit service manual.
• Check the stop valve.
• Refer to "Check of outdoor thermistor".
Refer to outdoor unit service manual.
• Replace the inverter P.C. board or the
outdoor electronic control P.C. board.
Refer to outdoor unit service manual.
• Confi rm the abnormality in detail using
the failure mode recall function for
outdoor unit.