Turn the power supply OFF.
Is there rated voltage in the power supply?
Yes No
Check for incorrect indoor-outdoor connecting wiring.
Check the power supply.
• Turn OFF inverter-controlled lighting equipment.
• Turn OFF the power supply and then turn ON again.
• Press EMERGENCY OPERATION switch.
A
Is serial signal error indicated 6 minutes later?
B Yes
• Reinstall either the unit or the light away from each other.
• Attach a f lter on remote control receiving section of the indoor unit.
No
NOTE: Refer to the indoor unit service manual.
Is there rated voltage between outdoor terminal block S1 and S2?
Check for miswiring, broken wires, and loose wire connection between the power supply and outdoor terminal block S1 and between the power supply and outdoor terminal block S2.
Wait for 2 or more minutes after the power supply is turned on.
Touch S2 and S3 with tester probes and start the emergency operation.
When the emergency operation starts, does the rated voltage occur for 2 sec- onds between indoor terminal block S2 and S3?
No Yes
Replace the indoor electronic control P.C. board.
Does the left lamp of the OPERA- TION INDICATOR lamp on the indoor unit blink continuously 6 minutes after the emergency operation starts?
No Does DC (10 V or more) occur between L68A and L68B on the outdoor relay P.C. board?
Yes
Does the outdoor LED blink 6 times?
Yes
Replace the outdoor relay P.C.
board. 1 No
Does DC (more than 0 V) occur between indoor terminal block S2 and S3?
Yes
Replace the outdoor inverter P.C.
board. 1 No
Turn the power supply OFF.
Start the emergency operation.
No Repair has been completed.
Replace the outdoor inverter P.C.
Electric charge may remain immediately 1.
after the power supply is turned OFF.
Perform the procedure after 3 minutes.
Replace the outdoor inverter P.C.
board and the outdoor relay P.C.
board. 1
Turn the power supply ON.
Does the left lamp of the OPERA- TION INDICATOR lamp on the indoor unit blink continuously 6 minutes after the emergency operation starts?
Yes
No
Replace the indoor electronic control P.C. board.
Yes
Replace the outdoor inverter P.C.
board and the outdoor relay P.C.
board. 1 Yes
A
B Turn the power supply ON.
No
Was the indoor unit ever connected to the Multi (MXZ) series and operated (turned on)?
The connection information to the Multi series is stored in the indoor unit. Refer to “Deleting the memorized abnormal condition” described in 10-2.1 to clear the error history. When the error history is being cleared, the connection information also will be initialized. The indoor unit will be compatible with a low-standby-power model after initialization.
OK Yes
No
• Turn OFF inverter-controlled lighting equipment.
• Turn OFF the power supply and then turn ON again.
• Press EMERGENCY OPERATION switch.
A
Is serial signal error indicated 6 minutes later?
B Yes
• Reinstall either the unit or the light away from each other.
• Attach a f lter on remote control receiv- ing section of the indoor unit.
No
Turn OFF the power supply.
Is there rated voltage in the power supply?
Yes No
Turn ON the power supply.
Check the power supply.
Is there rated voltage between outdoor terminal block S1 and S2? No Check the wiring.
Press EMERGENCY OPERATION switch once.
Does the left lamp of the OPERATION INDICATOR lamp light up?
<Conf rmation of the power to the indoor unit>
Yes
No
Is serial signal error indicated 6 minutes later?
Yes
No
Is there any miswiring, poor contact, or wire disconnection of the indoor/outdoor connect- ing wire?
Yes Correct them.
No
A
Turn OFF the power supply.
Check once more if the indoor/outdoor connecting wire is not miswiring.
Remove the indoor/outdoor connecting wire from outdoor terminal block S3.
Bridge the outdoor terminal block S2 and S3. 1 B
1. Miswiring may damage indoor electronic control P.C.
board during the operation.
Be sure to conf rm the wiring is correct before the opera- tion starts.
(Refer to the next page.)C Yes
MXZ Type
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
LED 1 LED 2 N 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.
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:
• Poor connection of the indoor/
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).
• Effects of the inverter lighting 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.
• Noise on the indoor/outdoor connecting wire
Pass the indoor/outdoor connecting wire through a different route if the existing wiring is arranged as below:
• The indoor/outdoor connecting wire runs near the power supply cable of other equipment.
• The indoor/outdoor connecting wire 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. Bridge the S2 and S3 of the outdoor terminal block . Does the left lamp of the OPERATION INDICATOR lamp light up?
<Confirmation of the power to the indoor unit>
Outdoor control P.C. board
Blinking LED1 LED2 LED3
LED 1 LED 2 LED 3
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 2 LED 1
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 LED1 LED2