Mitsubishi Mr.SLIM MFZ-KA09NA Service Manual page 20

9-4. TROUBLESHOOTING CHECK TABLE
OPERATION INDICATOR
NOTE: Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
Self check table
Abnormal
No.
Operation indicator lamp
point
Left lamp flashes.
0.5-second ON
Miswiring
1 or serial
signal
0.5-second OFF
Outdoor
control
2
Left lamp lights up
system
Indoor coil
Left lamp flashes.
thermistor
2-time flash
3
tempera-
2.5-second OFF
ture
thermistor
Left lamp flashes.
3-time flash
Indoor fan
4
motor
2.5-second OFF
Left lamp flashes.
Indoor
4-time flash
5
control
system
2.5-second OFF
Left lamp flashes.
5-time flash
Outdoor
6
power
system
Left lamp flashes.
6-time flash
Outdoor
7
thermistors
Left lamp flashes.
7-time flash
Outdoor
8
control
system
Left lamp flashes.
14-time flash
Other
9
abnormality
2.5-second OFF
Left lamp flashes.
15-time flash
Indoor
10
damper
2.5-second OFF
NOTE: When the indoor unit has started operation and the above failures are detected (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.
OBH568A
· Flashing of OPERATION INDICATOR lamp (left-hand side lamp)
Lighted
indicates abnormalities.
Blinking
Not lighted
Symptom
Indoor unit
and outdoor
unit do not
operate.
Outdoor unit
does not
operate.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Check point
When the serial signal from the outdoor unit is
not received for a maximum of 6 minutes.
When it cannot properly read data in the
nonvolatile memory of the outdoor electronic
control P.C. board.
When the indoor coil or the room temperature
thermistor is shorts or opens circuit.
When the rotational frequency feedback
signal is not emitted during the indoor fan
operation.
When it cannot properly read data in the
nonvolatile memory of the indoor electronic
control P.C. board.
The compressor stops 3 times consecutively
for over current protection or start-up failure
protection within 1 minute after start-up.
When the outdoor thermistors short or open
circuit during the compressor operation.
When it cannot properly read data in the
nonvolatile memory of the outdoor electronic
control P.C. board.
An abnormality other than above mentioned is
detected.
When the damper is not located
at the designated position.
20
Countermeasure
mis-wiring and serial signal
the LED on the outdoor
electronic control P.C. board.
indoor coil thermistor, and the
room temperature thermistor
on 9-7.
control P.C. board.
manual.
Check the stop valve.
manual.
electronic control P.C. board.
manual.
detail using the failure mode
recall function.
manual.