Samsung AVMKH020EA0 Service Manual page 234

8-2-51. Communication error after the completion of tracking
Outdoor unit display
Indoor unit display
Judgment method
Causes
Check the display part with pressing the rest
key(K3) of the outdoor unit PCB.
Is there any response of the indoor unit
at the display on tracking?
Remove the communication wire
connecting from the outdoor unit to the
indoor unit, and then measure 2 wires of
the outdoor unit with scope.
Is the voltage between both wires square
wave over DC 0.7V?
Check the communication wire connecting from the
outdoor unit to the indoor unit. If there is no defect,
search the indoor unit that interrupts the communication
by connecting the indoor unit one by one. And after
check a wire, displace the indoor unit PCB.
+0.7V
-0.7V
(Operation) (Timer)
- When it is not communicated between the indoor unit and outdoor unit during the operation
- Communication error between the indoor unit and outdoor unit
Yes
Yes
Yes
GOOD
- 233 -
(Fan) (Filter) (Removing frost)
No
Search for the indoor unit displayed the
communication error after 2 minutes, and check
the duplication of PCB address setup.
(The communication error is occurred due to
address duplication.)
In this case, the communication error is occurred at
the every indoor unit (over 2ea) set wrong address.
If there is no defect in address, replace the indoor unit
PCB after check the communication wire.
No
After check the communication wire
and connecter of the outdoor unit PCB,
replace the PCB.
BAD
Troubleshooting