Mitsubishi Electric MSH-C18TV, Service Manual

Page: 36 / 60

36
11-2. Instruction of troubleshooting
❈
1<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.”
Start
Indoor unit
operates.
Outdoor unit
doesn't
operate.
Indoor unit
doesn't receive
the signal from
remote controller.
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 44.
Refer to
D
"Check of
outdoor unit"
on page 40
or 41.
Refer to
B
"Check of
remote controller
and receiver
P.C. board"
on page 39.
Flash on and
off at 0.5-
second interval
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
6-time flash
Cause:
Outdoor unit
• Trouble of
thermistor
in outdoor
unit
Refer to
G
"How to
check mis-wiring and
sirial singal error
(When outdoor unit
doesn't operate)"
on page 43.
❈
1
Check room
temperature
thermistor
and indoor
coil thermis-
tor.
Refer to
"Test point
diagram and
voltage"
on page 44.
1-time flash
Cause:
Indoor/
Outdoor unit
• Trouble of
serial signal
Refer to
A
"Check of
indoor fan
motor"
on page 39.
MSH-C24TV only
7-time flash
Cause:
Outdoor unit
• Trouble of
outdoor unit
control
system
Replace the
deicer
P.C. board.
1. Check indoor /
outdoor
connecting wire.
2. Refer to
C
"Check of indoor
electronic control
P.C. board"
on page 40.
MSH-C24TV only
Outdoor
unit doesn't
stop even
if indoor unit
stops.
Refer to
E
"Check of
outdoor unit"
on page 41.
Refer to
H
"Check of
outdoor
thermistor"
on page 43.
Indoor unit
operates.
Outdoor unit
doesn't operate
normally.
Unit doesn't
operate
normal
operation in
COOL or
HEAT mode.
Refer to
F
"Check of
R.V. coil"
on page 42.
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