Mitsubishi Electric MFZ-KA25VA Service Manual page 24

10-3. Instruction of troubleshooting
Start
Indoor unit
operates.
Outdoor unit
doesn't
operate.
Outdoor unit
Outdoor unit
operates only
doesn't
in Test Run
operate
operation.
even in
w1
Test Run
operation.
w1
Refer to
Check room
"How to check
temperature
inverter/
thermistor.
compressor".
Refer to 10-7.
"Test point
diagram and
voltage".
Left lamp
Left lamp
2-time flash
Flash on and off
Cause:
at 0.5-second
Indoor unit
intervals
• Trouble of
Cause:
room temp-
Indoor/
erature/
Outdoor unit
indoor coil
• Mis-wiring
thermistor
or trouble
of serial signal
Check room
Refer to 10-6.
D "How to
temperature
thermistor
check the
and indoor
mis-wiring
coil thermis-
and serial
tor.
signal error
Refer to 10-7.
(when
"Test point
outdoor unit
diagram and
doesn't work)".
voltage".
Indoor unit operates.
Outdoor unit doesn't
operate normally.
Indoor unit
Unit doesn't
operates, when
operate
EMERGENCY
normal
OPERATION
operation in
switch is pressed.
COOL or
HEAT mode.
Refer to
Refer to 10-6.B
"Check of
"Check of
R.V. coil".
remote controller
and receiver
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
A-1, A-2
indoor
"Check of
electronic
indoor fan control
motor". P.C. board.
Indoor unit
OPERATION INDICATOR
doesn't receive
lamp on the indoor unit is
the signal from
flashing on and off.
remote controller.
Indoor unit
doesn't 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.C
"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".
24
If blinking of OPERATION
INDICATOR lamp cannot be
checked, it can be checked with
failure mode recall function.
w1
"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: Cause:
Outdoor unit Outdoor unit
• Trouble of • Other
outdoor abnormality
control
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.
Left lamp
15-time flash
Cause:
Indoor unit
• Trouble of
damper
Refer to
10-6. E
"Check of
damper".