Service manual

42
10-2. Troubleshooting procedure
The following procedure facilitates identifying defective points.
Details of OPERATION INDICATOR lamp flashing are located on page 43.
Start
Indoor unit
operates.
Outdoor unit
doesn't
operate.
Indoor unit
does'nt 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
does'nt
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 56 or 57.
Refr to A
"How to check
inverter/
compressor"
on page 47.
Refer to H
"Check of
remote controller
and receiver
P.C. board"
on page 50.
Refer to I
"Check of indoor
electronic control
P.C. board"
on page 51.
1-time flash
Cause: Indoor/
Outdoor unit
• Mis-wiring
• Serial signal
error
2-time flash
Cause:
Indoor unit
• Trouble of
room temper-
ature/ indoor
coil thermistor
3-time flash
Cause:
Indoor unit
• Trouble of
indoor fan
motor
5-time flash
Cause:
Outdoor unit
• Outdoor
power
system
abnormality
6-time flash
Cause:
Outdoor unit
• Trouble of
thermistor
in outdoor
unit
7-time flash
Cause:
Outdoor unit
• Trouble of
outdoor
control
system
Refer to P
"Checking
mis-wiring and
serial signal
error"
on page 55.
Check room
temperature
thermistor and
indoor coil
thermistor.
Refer to
"Test point
diagram and
voltage" on
page 56 or 57.
Refer to G
"Check of
indoor fan
motor"
on page 49.
Refer to A
"How to check
inverter/
compressor"
on page 47.
Refer to J
"Check of
outdoor
thermistors"
on page 51.
Replace the
outdoor
electronic
control
P.C. board.
MSZ12UN
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.
OB297--2.qxp 04.2.4 4:21 PM Page 42