Mitsubishi Electric MS-07NV - E2 (WH), Руководство по обслуживанию, Страница: 38 / 64

38
10-2 Instruction of troubleshooting
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 41.
Indoor unit
doesn’t receive
the signal from
remote
controller.
Refer to
”Check of
receiver P.C.
board” on page
40.
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
flash, when the EMER-
GENCY OPERATION
switch is pressed.
Refer to “Check of
indoor electronic control
P.C. board” on page 41.
Cause:Indoor unit
2-time-Room temperature/Indoor coil thermistor trouble
3-time-Indoor fan motor trouble
D
B
Check room temperature
thermistor. Refer to“Test
point diagram and volt-
age” on page 42~44. Refer to
“Check of indoor
fan motor” on
page 40.
Check indoor coil
thermistor. Refer
to“Test point dia-
gram and voltage”
on page 42~44.
2-time flash
2.5-second OFF
3-time flash
2.5-second OFF
Start
C
A
10-2-1 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
Detect 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
Check point
●
Check thermistor calibration.
●
Reconnect connector.
●
Check indoor electronic control P.C.
board.
●
Disconnect connector CN211 and then
check connector CN121
2
-
3
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 connector.
OB206t-2.qxp 25/9/97 8:36 PM Page 38