123
13-2. Instruction of troubleshooting
<MU-07/09/12RV,MUH-07/09/12RV,MUX-10/18/24RV> (Refer to page 124 for MXZ-18/32RV)
Indoor unit oper-
ates. Outdoor unit
doesn’t operate.
Outdoor unit
operates in
only Test
Run opera-
tion.
Outdoor unit
doesn’t oper-
ate even in
Test Run
operation.
Check room
temperature
thermistor.
Refer to
“Check of
outdoor unit”
on page 133
and 134.
Indoor unit doesn’t
receive the signal
from remote
controller.
Refer to
“Check of remote
controller and
receiver P.C. board”
on page 132.
OPERATION INDICATOR
lamp on the indoor unit is
flashing on and off.
Indoor unit doesn’t
receive the signal from
remote controller.
Also, OPERATION INDI-
CATOR lamp doesn’t
light, when the EMER-
GENCY OPERATION
switch is pressed.
Refer to “Check of
indoor electronic control
P.C. board” on page 133.
Cause:indoor/outdoor unit
connecting
Trouble of mis-wiring
Trouble of the serial signal
Cause:Indoor unit
2-time-Room tempera-
ture/Indoor coil
thermistor trouble
3-time-Indoor fan motor
trouble
Refer to
“How to check
mis-wiring and
signal error
(when outdoor unit
doesn’t work)”
on page 135.
❈
1
6-time flash
2.5-second OFF
Cause:outdoor unit
6-time-Check the defrost
thermistor
E
D
B
Check room temperature
thermistor. Refer to“Test
point diagram and volt-
age” on page 142.
Refer to
“Check of indoor
fan motor” on
page 132.
Check indoor coil
thermistor. Refer
to“Test point dia-
gram and voltage”
on page 142.
❈
1<The case of the trouble of the serial signal>
When the power is turned off and then turned on again, the indi-
cation shows “the trouble of mis-wiring.”
2-time flash
2.5-second OFF
3-time flash
2.5-second OFF
Start
1-time flash
C
A
(
