Samsung Electronics
77
4-2 Troubleshooting by symptoms
Indoor unit display
Symptom
Communication error between the indoor and outdoor unit for two minutes
Failure
Communication error between the indoor unit and outdoor unit
4-2-1 Communication error after finishing Tracking
No
Yes
No
Yes
Is there a response from the indoor PCB?
(LED02 (GRN) is not ON)
In this case, is the
voltage waveform between the lines square
wave with amplitude over ±0.7V as shown
in the following picture?
+0.7V
-0.7V
Good
Bad
Check the communication cable and
replace the indoor unit PCB
Remove the communication cable
connecting the outdoor unit to indoor unit,
and measure the signal on LINE 2 of the
outdoor unit with a scope
Reconnect the cable connecting
the outdoor unit to the indoor unit
and restart the unit.
If the communication still doesn’t work,
replace the indoor unit PCB.
Check the communication
cable in the outdoor unit PCB
and replace the PCB
LED02
F3, F4
