Mitsubishi Electric MFZ-KJ25VE Service Manual page 23

10-3. INSTRUCTION OF TROUBLESHOOTING
Start
Indoor unit
operates.
Outdoor unit
does not
operate.
Outdoor unit
Outdoor unit
operates only
does not
in Test Run
operate
operation.
even in
Test Run
operation.
Refer to
Check room
"How to check
temperature
inverter/
thermistor.
compressor".
Refer to 10-7.
"Test point
diagram and
voltage".
Left lamp
Left lamp
Flash ON and
2-time flash
OFF at
Cause:
0.5-second
Indoor unit
intervals
• Trouble of
Cause:
room temp-
Indoor/
erature/
Outdoor unit
indoor coil
• Miswiring
or trouble thermistor
of serial signal
Check room
Refer to 10-6.
temperature
"How to
thermistor
check the
and indoor
miswiring
coil thermis-
and serial
tor.
signal error
Refer to 10-7.
(when
"Test point
outdoor unit
diagram and
does not
voltage".
work)".
OBH666C
Indoor unit operates.
Outdoor unit does
not operate normally.
Indoor unit
Unit does
operates, when
not operate
EMERGENCY
normal
OPERATION
operation in
switch is pressed.
COOL or
HEAT mode.
Refer to
Refer to 10-6.
"Check of
"Check of
R.V. coil".
remote controller,
display receiver
P.C. board and
indoor control
P.C. board".
Left lamp Left lamp
3-time flash
4-time flash
Cause: Cause:
Indoor unit
Indoor unit
• Trouble of • Trouble of
indoor fan indoor unit
motor
control
system
Refer to 10-6. Replace the
"Check of indoor
indoor fan electronic
motor". control
P.C. board.
Indoor unit does
OPERATION INDICATOR
not receive
lamp on the indoor unit is
the signal from
flashing ON and OFF.
remote controller.
Indoor unit
does not operate,
when
EMERGENCY
OPERATION
switch is pressed.
1. Check indoor / outdoor
connecting wire.
(Check if the power
is supplied to the
indoor unit.)
2. Refer to 10-6.
"Check of indoor
electronic control
P.C. board and indoor
fan motor".
Left lamp Left lamp
5-time flash 6-time flash
Cause: Cause:
Outdoor unit Outdoor unit
• Outdoor • Trouble of
power thermistor
system in outdoor
abnormality unit
Refer to
Refer to
"How to check
"Check of
the inverter/
outdoor
compressor".
thermistors".
23
If blinking of OPERATION
INDICATOR lamp cannot be
checked, it can be checked with
failure mode recall function.
"Test Run operation" means the
operation within 30 minutes after
EMERGENCY OPERATION switch
is pressed.
Refer to outdoor unit service manual.
Left lamp Left lamp
7-time flash 14-time flash
Cause: or more
Outdoor unit Cause:
• Trouble of Outdoor unit
outdoor • Other
control abnormality
system
Check
Replace the
"Flow chart of
inverter P.C.
the detailed
board or
outdoor unit
the outdoor
failure mode
electronic
recall function."
control P.C.
board.