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Check method & Handling
(1) The power for the M-NET
transmission line is not supplied
from the outdoor unit.
(2) Short circuit of the transmission line
(3) Incorrect wiring of the M-NET
transmission line on the outdoor
unit side.
1
Disconnected wire for the MA
remote controller and
disconnected line to the terminal
block.
2
The indoor transmission line is
connected incorrectly to terminal
block (TB7) to the transmission
line for centralized control.
(4) Disconnected transmission line on
the remote controller side
(5) Remote controller failure
(1) The power for the indoor unit is not on.
1
The main power of the indoor unit (AC220~240V) is OFF.
2
The connector on the indoor unit controller board has come off.
3
The fuse on the indoor unit controller board has melted.
4
Transformer failure and disconnected wire of the indoor unit.
5
The indoor controller board failure.
(2) The main board of the indoor and the outdoor unit failure
As the indoor unit does not interact with the outdoor unit, the outdoor unit
model cannot be recognized.
Factors
Phenomena
Checke method & Handling
1
2
(a) Check voltage of the M-NET remote
controller transmission terminal.
i) If the voltage is 17V-30V
→
The M-NET remote controller is
defective.
ii) If there is 17V or less
→
Refer to
9
.[4].7.(2) “Outdoor
unit transmission power source
circuit failure judgment”.
When the factor (2) and (3)
apply, self-diagnosis LED of the
outdoor unit works and the
check code 7102 will be
displayed.
Even if the operation SW on
the remote controller is
pressed, the display remains
unlit and the unit does not
start running.
(Power indicator does not
appear on the screen.)
When turning on the remote
controller operation SW, a
temporary operation display is
indicated, and the display
lights out immediately.
NO
YES
YES
NO
NO
YES
YES
NO
NO
YES
YES
NO
*1
Check indoor LED3
Lighting?
Lighting
Extinguishing or
unable to confirm
Check indoor unit
power source
terminal block voltage
Check fuse on circuit
board
Check main power source
of power source wiring
Apply power
source again
Improper connector
connection
Check self-diagnosis function af-
ter powering outdoor unit again
Check 220V circuit
for short circuit
and ground fault
Check cause of trans-
former disconnection.
•Ground fault on circuit
board
•Ground fault on sensor,
LEV
Check transformer
resistance value
Check connection of
connector
Check self-diagnosis
function of outdoor unit
Faulty indoor
controller board
Repair faulty
point
Accidental
trouble
Faulty outdoor
unit control
circuit board
AC 220V?
Blown?
Disconnected
Within rated?
Changed?
Changed?
Check for the change of LED
display by operating dip switch
SW1 for self-diagnosis.
*1 Check the transformer in accordance with the “TROUBLESHOOTING” in the indoor unit’s service handbook.
(2) In the case of the M-NET remote controller