Sinclair MV-P09BI, Service Manual, Page: 34 / 57

31
Service Manual
(2) Troubleshooting for communiction malfunction
Main check point:
●Check whether the connection wire for indoor and outdoor units and the wires inside the indoor unit is connected well;
●Check whether the mainboards of indoor unit or outdoor unit are damaged;
Check flow chart:
Replace mainboard of
outdoor unit
Wires are connected
correctly?
Is malfunction
eliminate?
Communication malfunction
for some indoor unit
End
No
No
No
Yes
Yes
Yes
Whether the indoor unit
resumes normal?
Disconnect the power, and
check connection wire for indoor
and outdoorunits and wires inside
electric box areconnected
correctly
De-energize the unit, exchange the communication
wirefor the indoor unit with normal communication
and the indoor unit with malfunction, energize the
unit and thenwait for 3mins
Replace mainbaord of indoor
unit with malfunction
Connect wires
according to wiring
diagram