34
LED1 LED2
LED indication for communication status
Communication status is indicated by the LED.
Unit status
No
Blinking: Normal communication
Lighted: Abnormal communication or not connected
s
e
Y
Not lighted: The outdoor P.C. board is abnormal.
NOTE: "Lighted" and "Not lighted" in the table below
does not indicate abnormal.
MXZ-2D33/2D40/2D53VA/2D53VAH
Outdoor display P.C. board
o
N
o
N
LED 1
LED 2
Unit A
Unit B
status
status
Yes
o
N
D
D
s
e
Y
s
e
Y
No
Yes
No
(Lighted or
not
lighted)
*1Turn OFF the breaker before replacing the indoor electronic control
P.C.
board.
Refer to the indoor unit service manual.
*2 The LED indicates the status of serial
communication.
Check the communication status.
*3 Turn OFF the breaker before replacing the inverter P.C. board.
Be careful of residual voltage of smoothing capacitor.
*4 Remove the short-circuit between outdoor terminal block
S2 and S3. Connect the indoor/outdoor connecting wire.
C
Turn ON the power supply.
Is there rated voltage
between outdoor
terminal block S1 and S2 ?
Check the power supply
and correct the problem.
Press the EMERGENCY
OPERATION switch
once.
Does the OPERATION
INDICATOR lamp light
up? <Confirmation of
the power to the indoor
unit>
Is there rated
voltage between
outdoor terminal
block S1 and S2?
Check the indoor/outdoor
connecting wire and
correct the problem.
Replace the indoor
electronic control
P.C. board. *1
Is serial signal error
indicated 6 minutes
later?
Is there any miswiring,
poor contact, or wire
disconnection of the
indoor/outdoor
connecting wire?
Check the indoor/outdoor
connecting wire and
correct the problem.
Turn OFF the power supply.
Turn ON the power supply.
Does the LED on the
outdoor display P.C.
board or the outdoor control
P.C. board repeat quick
BLINKING and OFF? *2
If the trouble sometimes occurs,
possible causes are as follows:
3RRUFRQQHFWLRQRIWKHLQGRRU
outdoor connecting wire
Check for intermediate connection of
the indoor/outdoor connecting wire,
loose connection to the terminal block,
and cut wire inside the cable.
If any of them is found, correct the
problem(s).
(IIHFWVRIWKHLQYHUWHUOLJKWLQJ
on the indoor unit
If the trouble occurs or does not occur
depending on whether the light is on
or off, distance the lighting from the
indoor unit or apply the glass filter on
the receiving part of the indoor unit.
1RLVHRQWKHLQGRRURXWGRRU
connecting wire
Pass the indoor/outdoor connecting
wire through a different route if the
existing wiring is arranged as below:
7KHLQGRRURXWGRRUFRQQHFWLQJZLUH
runs near the power supply cable of
other equipment.
7KHLQGRRURXWGRRUFRQQHFWLQJZLUH
is detoured and run long.
Remove the
indoor/outdoor connecting
wire from the outdoor
terminal block connected
with the indoor unit on
which miswiring or the
serial signal error is
indicated. Short-circuit
between S2 and S3 of the
outdoor terminal block .
Outdoor control P.C. board
Blinking
LED1 LED2 LED3
LED 1
LED 3
LED 2
Pattern
1
2
Unit B
status
Unit D
status
Unit A
status
Unit C
status
Unit E
status
Not lighted
Outdoor control P.C. board
Blinking
LED3 LED2 LED1
LED 3
LED 1
LED 2
Pattern
1
2
Unit B
status
Lighted
Unit A
status
Unit D
status
Not lighted
Unit C
status
MXZ-3D54/3D68/4D72VA
MXZ-4D83/5D102VA
Replace the indoor
electronic control
P.C. board. *1 *4
Replace the inverter P.C.
board or the outdoor control
P.C. board. *3 *4
OBH623D
