Service manual

90
12-2. Instruction of troubleshooting
Start
Indoor unit
operates.
Outdoor unit
doesn't
operate.
Indoor unit
doesn't receive
the signal from
remote controller.
Indoor unit
operates.
But indoor
unit doesn't
blow out
cool air.
Indoor unit
operates.
Outdoor unit
doesn't operate
normally.
OPERATION
INDICATOR
lamp on the
indoor unit is
flashing on
and off.
Outdoor unit
operates in
only Test Run
operation.
Outdoor unit
doesn't
operate
even in
Test Run
operation.
Indoor unit
operates,
when the
EMERGENCY
OPERATION
switch is
pressed.
Indoor unit
doesn't operate,
when the
EMERGENCY
OPERATION
switch is
pressed.
Check room
temperature
thermistor.
Refer to
"Test point
diagram and
voltage" on
page 102.
MUH-A07/A09/A12WV
MUX-A19/A20/A22/
A25/A26WV
Refer to D
"Check of
outdoor unit"
on page 96
or 97.
Refer to B
"Check of
remote
controller
and receiver
P.C. board"
on page 95.
MUH-A07/A09/A12WV
MXZ-A18/A26/A32WV
Flash on and
off at 0.5-
second
intervals
Cause:
Indoor/
Outdoor unit
• Mis-wiring
2-time flash
Cause:
Indoor unit
• Trouble of
room temp-
erature/
indoor coil
thermistor
3-time flash
Cause:
Indoor unit
• Trouble of
indoor fan
motor
MUH-A07/A09/A12WV
MXZ-A18/A26/A32WV
6-time flash
Cause:
Outdoor unit
• Trouble of
thermistor
in outdoor
unit
MUH-A07/A09/A12WV
MXZ-A18/A26/A32WV
7-time flash
Cause:
Outdoor unit
• Trouble of
outdoor
control
system
Check room
temperature
thermistor
and indoor
coil thermis-
tor.
Refer to
"Test point
diagram and
voltage"
on page 102.
Refer to A
"Check of
indoor fan
motor"
on page 95.
Refer to H
"Check of
outdoor
thermistor"
on page 101
and others.
Replace the
deicer
P.C. board or
the outdoor
electronic
control P.C.
board.
MUH-A07/A09/A12WV
MXZ-A18/A26/A32WV
1-time flash
Cause:
Outdoor /
Indoor unit
• Trouble of
serial signal
Refer to G "How to check
mis-wiring and serial signal
error (When outdoor unit
doesn't work)" on page 100.
W1
1. Check indoor /
outdoor
connecting wire.
2. Refer to C
"Check of indoor
electronic control
P.C. board"
on page 96.
Outdoor unit
doesn't
stop even
if indoor unit
stops.
Unit doesn't
operate
normal
operation in
COOL or
HEAT mode.
MU/H-A07/A09/A12WV
Refer to E
"Check of
outdoor unit"
on page 98.
MUH-A07/A09/A12WV
MXZ-A18/A26/A32WV
Refer to F
"Check of
R.V. coil"
on page 99
and others.
MUX-A10/A19/A20/
A22/A25/A26WV
Refer to I
"Check of
indoor/outdoor
units' connection
and outdoor unit"
on page 101.
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”.
MXZ-A18/A26/A32WV
5-time flash
Cause:
Outdoor unit
• Outdoor
power
system
abnormality
Refer to
"Check of
inverter/
compressor"
and "Check
of power
supply".
NOTE:
As for outdoor unit
MXZ type, refer to
service manual
OB319.
As for outdoor unit
MUX-A22WV,
refer to
service manual
OB318 REVISED
EDITION-A.
MSC-A07WV - MU-A07WV - MUH-A07WV - MUX-A10WV - MUX-A25WV -
MSC-A09WV - MU-A09WV - MUH-A09WV - MUX-A19WV - MUX-A26WV -
MSC-A12WV - MU-A12WV - MUH-A12WV - MUX-A20WV -
E1E1E1E1
E1E1E1E1E1
E1E1E1E1E1
OB307C-3.qxp 04.5.11 1:18 PM Page 90