Mitsubishi Electric MSZ-GA50VA Service Manual page 15

9-3. 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. w
even in
Test Run
operation. w
Check room Refer to
temperature "How to check
thermistor.
inverter/
Refer to 9-7.
compressor".
"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 9-6.
D "How to
temperature
thermistor
check
and indoor
mis-wiring
coil thermis-
and serial
tor.
signal error".
Refer to 9-7.
"Test point
diagram and
voltage".
Indoor unit operates.
Outdoor unit doesn't
operate normally.
Unit doesn't
Indoor unit
operate
operates, when
normal
EMERGENCY
operation in
OPERATION
COOL or
switch is pressed.
HEAT mode.
Refer to Refer to 9-6.B
"Check of
"Check of
remote controller
R.V. coil".
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 9-6. Replace the
A "Check of
indoor
indoor fan
electronic
motor".
control
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 9-6.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
inverter/
outdoor
compressor".
thermistors".
15
If blinking of OPERATION
INDICATOR lamp cannot be
checked, it can be checked with
failure mode recall function.
w "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.