Mitsubishi Electric MSC-GA20VB- E1 Service Manual page 12

9-2. Instruction of troubleshooting
MSC-GA20VB -
E1
MSC-GA25VB -
E1
MSC-GA35VB -
E1
Start
Indoor unit
operates.
Outdoor unit
doesn't
operate.
Outdoor unit Outdoor unit
operates in doesn't
only Test Run operate
operation. even in
Test Run
operation.
Check room
MUH-GA20/GA25/GA35VB
temperature
MUX-2A28/2A59/3A60/
thermistor.
3A63/2A70/4A73VB
Refer to 9-6.
Refer to
"Test point
"Check of
diagram and
outdoor unit".
voltage".
MUH-GA20/GA25/GA35VB
MXZ-A14/A18/A26/A32WV
Flash on and off at
0.5-second intervals
Cause:
Indoor/Outdoor unit
• Mis-wiring or
trouble of serial signal
Refer to 9-5. D "How to
check mis-wiring and serial
signal error (When outdoor
unit doesn't work)".
W1
W1.<The case of the trouble of the serial signal>
When the power is turned off and then turned on again, the indication shows "the trouble of mis-wiring".
As for outdoor unit MU type, refer to service manual OB386.
As for outdoor unit MUH type, refer to service manual OB387.
As for outdoor unit MUX type, refer to service manual OB384.
As for outdoor unit MXZ type, refer to service manual OB319 REVISED EDITION-A.
Indoor unit
operates.
Outdoor unit
doesn't operate
normally.
Outdoor unit Unit doesn't
doesn't operate
stop even normal
if indoor unit operation in
stops. COOL or
HEAT mode.
MUH-GA20/GA25/GA35VB
MU-GA20/GA25/GA35VB
MXZ-A14/A18/A26/A32WV
Check of wiring
Refer to
diagram of
"Check of
outdoor unit".
R.V. coil" and
MUH-GA20/GA25/GA35VB
others.
Refer to
"Check of
outdoor unit".
2-time flash
3-time flash
Cause:
Cause:
Indoor unit
Indoor unit
• Trouble of
• Trouble of
room temp-
indoor fan
erature/
motor
indoor coil
thermistor
Check room
Refer to 9-5.
temperature A "Check of
thermistor
indoor fan
and indoor
motor".
coil thermis-
tor.
Refer to 9-6.
"Test point
diagram and
voltage".
Indoor unit
doesn't receive
the signal from
remote controller.
Indoor unit
operates,
when the
EMERGENCY
OPERATION
switch is
pressed.
Refer to 9-5.
B "Check of
remote
controller
and receiver
P.C. board".
MXZ type
4-time flash
5-time flash
Cause:
Cause:
Indoor unit
Outdoor unit
• Trouble of
• Outdoor
indoor unit
power
control
system
system
abnormality
Replace the Refer to
indoor "Check of
electronic inverter/
control
compressor"
P.C. board. and "Check
of power
supply".
12
OPERATION
INDICATOR
lamp on the
indoor unit is
flashing on
and off.
Indoor unit
doesn't operate,
when the
EMERGENCY
OPERATION
switch is
pressed.
1. Check indoor /
MUX-2A28/2A59/3A60/
outdoor
3A63/2A70/4A73VB
connecting wire.
Refer to
2. Refer to 9-5. C
"Check of
"Check of indoor
indoor/outdoor
electronic control
units' connection
P.C. board".
and outdoor
unit".
7-time flash
6-time flash
Cause:
Cause:
Outdoor unit
Outdoor unit
• Trouble of
• Trouble of
outdoor
thermistor
control
in outdoor
system
unit
MUH-GA20/GA25/GA35VB MUH-GA20/GA25/GA35VB
MXZ-A14/A18/A26/A32WV MXZ-A14/A18/A26/A32WV
Refer to Replace the
"Check of deicer
outdoor P.C. board
thermistor" and others.
and others.
Indoor unit
operates.
But indoor
unit doesn't
blow out
cool air.
10-time flash
Cause:
Outdoor unit
MXZ type
• Outdoor
refrigerant
system
abnormality
MXZ type
Refer to
outdoor
refrigerant
system
related items.