Samsung DH052EAM Service Manual page 27

Troubleshooting
6-4-4 Communication error during the operation
Outdoor unit display
Indoor unit display
Disconnection
and short of
communication lines
Reason of error
To check the display after
pressing the reset key on outdoor PCB
When tracking, is there any
indoor answer from display part?
To measure the 2 lines of outdoor side
by scope after removing the
communication line connecting from
outdoor unit to indoor unit.
At this time, is the voltage
between lines spherical wave over DC ±0.7V
like below figure?
After connecting again the communication
line connecting from outdoor unit to indoor unit,
to remove the communication
connector on indoor unit PCB, and find the
indoor unit preventing communication
through connecting the communication
connectors each by each, and then exchange
the indoor unit PCB after line check.
+0.7V
-0.7V
26
Er → E1 (Communication error during the operation)
(Operation) (Timer)
Disconnection and short of outdoor heat exchanger temperature sensor
Disconnection or leak of Applied sensor
Yes
Yes
Good
(Airflow) (Filter)
Multi type
After 2 minutes, to check if PCB address
setting of indoor unit displayed th
communication error among indoor units is
No
overlapped or not.
(If the indoor unit address is overlapped, the
communication error is occurred.)
- In this case, the communication error is
occurred to over two indoor units set
wrong.
If address is no fault,
to exchange the indoor unit PCB after
communication line check.
No
To exchange PCB after checking
the outdoor unit communication line
and connector
Bad
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