Samsung AM030RXMDEH/EU Service Manual page 24

Troubleshooting
4-3-2 Communication error between indoor and outdoor units after completing tracking
(Error Code : E202)
1. How to check
Press the reset key (K3) of the outdoor unit PCB
then check the display part.
Is there any response from
display part during tracking?
Remove a communication line
from the outdoor unit to indoor units then
At that time, is the power
between the 2 lines a square wave?
Reconnect the communication line from the
outdoor unit to indoor units then remove all communication
connectors on the indoor unit PCB then find an indoor unit
that hampers communication by making a connection to
each unit and replace indoor unit PCB after checking out lines.
0.7V
0.7V
24
indoor units on the
Yes
measure 2 lines on the
outdoor unit with SCOPE.
Yes
No
After 2 minutes, find an indoor unit than shows a
communication error then check if PCB address setup
has overlapped. (If an indoor unit's address is overlapped,
communication error occurs)
- In that case, all indoor units with wrong address
setup for more than 2 will have communication error.
If there is any problem with the address, check the
communication line then replace indoor unit PCB.
No
Check the outdoor unit PCB communication
line and connector then replace the PCB
Good
Defective
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