OB274-34
11-2. Instruction of troubleshooting
Indoor unit oper-
ates. Outdoor unit
doesn’t operate.
Outdoor unit
operates in
only Test
Run mode.
Outdoor unit
doesn’t oper-
ate even in
Test Run
mode.
Check room
temperature
thermistor.
Refer to
“Check of
outdoor unit”
on page 38.
Indoor unit
doesn’t
receive the
signal from
remote
controller.
Refer to
”Check of
remote con-
troller and
receiver P.C.
board” on
page 37.
OPERATION INDICATOR
lamp on the indoor unit is
flashing on and off.
Indoor unit doesn’t
receive the signal
from remote con-
troller.
Also, operation
indicator lamp
doesn’t flash,
when the emer-
gency operation
switch is pressed.
Refer to “Check
of indoor electron-
ic control P.C.
board” on page
38.
Cause:Indoor unit
2-time-Room temperature/Indoor coil thermistor trouble.
3-time-Indoor fan motor trouble
D
B
Check room temperature.
Refer to“Test point dia-
gram and voltage” on
page 39 or 40.
Refer to
“Check of indoor
fan motor” on
page 36.
Check indoor coil
thermistor. Refer
to“Test point dia-
gram and voltage”
on page 39 or 40.
2-time flash
2.5-second OFF
3-time flash
2.5-second OFF
Start
C
A
1. Troubleshooting check table
Before taking measures make sure that the symptom reappears, for accurate troubleshooting.
Self check table
NO.
1
2
Abnormal
point
Indoor coil
thermistor
Room
tempera-
ture ther-
mistor
Indoor fan
motor
Indication
2-time flash
2.5-second OFF
3-time flash
2.5-second OFF
Symptom
Outdoor unit
does not run.
Indoor fan
repeats 12 sec-
onds ON and 3
minutes OFF.
When the indoor
fan breaks, the
fan keeps stop-
ping.
Detect method
Detects Indoor coil/room tem-
perature thermistor short or
open circuit every 8 seconds
during operation.
When rotational frequency
feedback signal is not emit
during 12-second indoor fan
operation.
Check point
●
Check resistance of thermistor.
●
Re-connect connector.
●
Check indoor electric P.C. board.
●
Disconnect connector CN211 and then
check connector CN121 - to make
sure rotational frequency feedback signal
of 1.5V or over exists.
●
Check indoor electronic control P.C.
board.
●
Check indoor fan motor.
●
Re-connect connector.
2
3
<MS09>
<MS09>
<MS12/15/17>
When the
remote controller
is pressed or
when the
EMERGENCY
OPERATION
switch is
pressed,the
indoor fan does
not rotate with
OPERATION
INDICATOR
lamp on.
Operation Indicator
flashing
· Flashing of the OPERATION INDICATOR lamp (on the left-hand side)
indicates possible abnormalities.
· The OPERATION INDICATOR lamp (on the left-hand side) is lighted during
normal operation.
• The following indication applies regardless of shape of the indicatior.