AUX ASW-H09B5B4/FAR3DI-C3, Service Manual

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48
（
17
）
F8-Outdoor Unit main PCB and module panel communication error
（
exclusive of Outdoor Unit machine of single panel
）
Explanation of
error
Cause: Only the models with the module panels separated with the
Outdoor Unit main PCBs may have this error. When the machine is
running normally, the module panel and the Outdoor Unit main PCB
would coordinate with each other on the communication to work and
when the communication is off, the Outdoor Unit main PCB would
raise the alarm of "main PCB and module panel communication error".
Only "module panel, data line and Outdoor Unit main PCB" are related
to such communication.
Inspection path:
data line connection → module panel power
→module panel →Outdoor Unit main PCB
Tools required
for inspection
Multimeter and regular module panel.
Frequent
problematic part
Module panel and main control data line, module panel and Outdoor
Unit main PCB.
Inspection
procedure and
key points
1. First check if the communication connection line (mostly 4 chips)
between the module panel and main contrl panel gets loose and if the
connection is faulted.
2. Measure and check with a multimeter if the power from the Outdoor
Unit main PCB is normal and especially note that if the 5V (3.3V)
power is led to the module panel. Eleminate the possibility that it's not
running normally because there is no 5V (3.3V) power at the module
panel.
3. The maintenance personnel shall replace the module panel of the
faulted air conditioner with a regular module panel taken with him and
if the communication error disappears when the Outdoor Unit machine
is switched on, it means the original module panel is faulted and if the
error is still there, maybe the Outdoor Unit main PCB shall be
replaced.