Troubleshooting Procedure - Mitsubishi Electric Mr.Slim MSZ09UN Service Manual

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.
Outdoor unit
does'nt
Outdoor unit
operate
operates in
even in
only Test Run
Test Run
operation.
operation.
Check room
temperature
Refr to A
thermistor.
"How to check
Refer to
inverter/
"Test point
compressor"
diagram and
on page 47.
voltage" on
page 56 or 57.
1-time flash
Cause: Indoor/
Outdoor unit
• Mis-wiring
• Serial signal
error
Refer to P
"Checking
mis-wiring and
serial signal
error"
on page 55.
Indoor unit
does'nt receive
the signal from
remote controller.
Indoor unit
operates, when
the EMERGENCY
OPERATION
switch is pressed.
Refer to H
"Check of
remote controller
and receiver
P.C. board"
on page 50.
2-time flash
3-time flash
Cause:
Cause:
Indoor unit
Indoor unit
• Trouble of
• Trouble of
room temper-
indoor fan
ature/ indoor
motor
coil thermistor
Refer to G
Check room
"Check of
temperature
indoor fan
thermistor and
motor"
indoor coil
on page 49.
thermistor.
Refer to
"Test point
diagram and
voltage" on
page 56 or 57.
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.
Indoor unit
doesn't operate,
when the
EMERGENCY
OPERATION
switch is pressed.
Refer to I
"Check of indoor
electronic control
P.C. board"
on page 51.
5-time flash
Cause:
Outdoor unit
• Outdoor
power
system
abnormality
Refer to A
"How to check
inverter/
compressor"
on page 47.
42
OPERATION
INDICATOR
lamp on the
indoor unit is
flashing on and
off.
7-time flash
6-time flash
Cause:
Cause:
Outdoor unit
Outdoor unit
• Trouble of
• Trouble of
outdoor
thermistor
control
in outdoor
system
unit
Refer to J Replace the
outdoor
"Check of
electronic
outdoor
control
thermistors"
P.C. board.
on page 51.