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Technical Information
8. Communication malfunction: (following AP1 for outdoor unit control board)
Mainly detect:
• Is there any damage to the indoor unit mainboard communication circuit?
• Detect the indoor and outdoor unit connection wire and indoor and outdoor units inside wiring is connect
well or not, if is there any damage?
Fault diagnosis process:
Start
Did the equipment operate normally
before the failure occurred?
Check wiring inside
of the indoor and
outdoor units
Are wires broken?
Check the
communication
circuit of the
outdoor unit
The communication
circuit is abnormal
Replace the main
board of the indoor
unit
The AP1 voltage
detection circuit
is at fault
If the fault is
eliminated?
Replace the main
board of the
outdoor unit
Correctly connect the
corresponding wires for
the indoor and outdoor
units with reference to the
wiring diagram
Check the wiring of the indoor
and outdoor units referencing
the wiring diagram
Is the connection right?
Is fault
eliminated?
Is fault
eliminated?
End
YES
NO
YES
NO
