Mitsumi electronic MS12NN (WH) Air Conditioner User Manual


 
32
11-2 Instruction of troubleshooting
Indoor unit oper-
ates. Outdoor unit
doesn’t operate.
Outdoor unit
operates in
only Test
Run mode.
Outdoor unit
does not
operate even
in Test Run
mode.
Check room
temperature
thermistor.
Refer to
“Check of
outdoor unit”
on page 36.
Indoor unit
dosen’t
receive the
signal from
remote
controller.
Refer to
”Check of
receiver P.C.
board” on
page 35.
Operation monitor lamp on
the indoor unit is flashing
on and off.
Indoor unit doesn’t
receive the signal
from remote con-
troller.
Also, operation
monitor lamp
doesn’t flash,
when the emer-
gency operation
switch is pressed.
Refer to “Check
of indoor electric
control P.C. board”
on page 36.
Cause:Indoor unit
2-times-Room temperature/Indoor coil thermistor trouble.
3-times-Indoor fan motor trouble
D
B
Check room temperature.
Refer to“Test point dia-
gram and voltage” on
page 37 and 38.
Refer to
“Check of indoor
fan motor” on
page 34.
Check indoor coil
thermistor. Refer
to“Test point dia-
gram and voltage”
on page 37 and 38.
2-time flash
2.5-second OFF
3-time flash
2.5-second OFF
Start
C
A
11-2-1 troubleshooting check table
Operation Indicator
w 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 2 seconds
during operation.
When rotational frequency
feedback signal is not emit
during 12-second indoor fan
operation
Repair
Check thermistor calibration
Reconnect connector
Check indoor 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
Reconnect conector
2
3
MS09NW only
MS09NW only
MS12NN
MS15NN
MS17NN
When the
remote controller
is pressed or
when the
Emergency
operation switch
is pressed,the
fan does not
rotate,with
Operation indi-
cator lamp on.
Look at the left lamp flash for the self check table.
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