Samsung AVMKH020EA0 Service Manual page 233

8
Troubleshooting
8-2-50. Communication error between the indoor unit and outdoor unit on tracking
Outdoor unit display
Indoor unit display
Judgment method
Causes
Compare and check the setting switch setup
value for indoor unit installation number of
outdoor unit PCB with the actual indoor unit
installation number.
Is same the actual indoor unit
installation number and the setting
switch setup value for indoor unit
installation number?
Yes
Press the reset key(K3) of the outdoor unit PCB
and check the number of indoor unit responding
to the tracking at display part.
Is there any response of indoor unit at display
part on tracking?
Yes
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?
Yes
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.
(Operation) (Timer)
- When the number of indoor unit of installation switch mismatch with communicated indoor unit on
- tracking the outdoor unit
- Communication error between the indoor unit and outdoor unit, and the setting switch setup error for
- the installation number of indoor unit
- 232 -
(Fan) (Filter) (Removing frost)
No
After right setting the setting switch setup
value for indoor unit installation number of
outdoor unit, perform the tracking again by
pressing the reset key(K3) of PCB.
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.
No
If there is no defect in address,
replace the indoor unit PCB after check the
communication wire.
After check the communication wire
and connecter of the outdoor unit PCB,
replace the PCB.