Haier MVAH018MV2AA Service Manual page 42

[06] Communication circuit between indoor and outdoor
If wiring between P and
If the port of CN15 on
indoor PCB is normal
If the port of CN19 on outdoor
connecting board is normal
If outdoor power source is normal
If power supply is failure
Check outdoor PCB, if faulty, replace it
Q is wrong or broken
down
No
Yes
Yes
No
No
If there is noise
No
Modify the communication wire
Yes
No
Modify the port
No
Yes
Electrify the outdoor
Yes
Clear the failure code
Yes
Check and eliminate noise
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