Mitsubishi Electric MSH-18NV Service Manual page 22

10-2. Instruction of troubleshooting
Indoor unit
operates. Outdoor
unit doesn't
Outdoor unit Outdoor unit
operates in doesn't
only Test operate even
Run in Test Run
operation. operation.
Refer to
Check room
"Check of
temperature
outdoor unit"
thermistor.
on page 26.
Refer to
E
"How to check
mis-wiring and
signal error
(when outdoor unit
doesn't work)"
on page 27. 1
Indoor unit
doesn't receive
the signal from
remote
controller.
Refer to "Check
B
of remote controller
and receiver P.C.
board" on page 25.
1-time flash
D
Cause:indoor/outdoor unit
connecting
( Trouble of mis-wiring
Trouble of the serial signal
Start
Operation Indicator lamp
on the indoor unit is
flashing on and off.
2-time flash
2.5-second OFF
3-time flash
2.5-second OFF
Cause:Indoor unit
2-time-Room
temperature/Indoo
r coil thermistor
trouble
3-time-Indoor fan motor
trouble
Refer to
Check indoor coil
"Check of indoor
thermistor. Refer
fan motor" on
to"Test point
page 25.
diagram and
voltage" on page
28.
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."
22
Indoor unit doesn't
receive the signal from
remote controller.
Also, Operation Indicator
lamp doesn't flash, when
the EMERGENCY
OPERATION switch is
pressed.
Refer to C "Check of
indoor electronic control
P.C. board" on page 26.
6-time flash
2.5-second OFF
Cause:outdoor unit
6-time-check the defrost
thermistor
A Check room temperature
thermistor. Refer to"Test
point diagram and
voltage" on page 28.