Haier AS71S2SF1FA-BC Service Manual page 39

10.3.10 The communication fault between indoor and outdoor
Indoor display E7
outdoor display LED1 flash 15 times
Method of Communication is detected by checking the indoor PCB and the outdoor PCB.
Malfunction
Detection
Malfunction ■ The outdoor PCB broken leads to communication fault.
Decision ■ The indoor PCB broken leads to communication fault.
Conditions
Supposed ■ Communication wiring disconnected.
Causes ■ The indoor PCB is broken.
■ The outdoor PCB is broken.
■ The Module PCB is broken.
Troubleshooting * Caution Be sure to turn off power switch before connect or disconnect connector, or else
malfunction occurs again after a while
cable between the indoor and outdoor
is well connected or whether its core
wires are well insulated or its
Check the indoor mainboard：only indoor
charged.
Measure the voltage between 3 and 4 of IC6
on the indoor mainboard with a multimete .And
measure the voltage between CN23(C) and
CN21(L) with a multimeter .
parts damage may be occurred.
Restart the a/c and it
becomes normally.
NO
If starting up normally, but
YES
Check whether the linking
L/N is not reversed.
YES
YES
(A)
The outdoor
YES
mainboard needs
dehumidification.
The outdoor
NO
mainboard needs
dedust.
Reconnect the linking
cable or replace the
linking cable with new
one.
NO
36
Installations
Domestic air conditioner