Samsung AC180JNHPKH/AR, Service Manual

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4-12 Samsung Electronics
4-3-8 Communication error after finishing tracking (E202)
1. Check items
1) Is the communication cable short/open?
2) Is there a response from the indoor unit PCB?
2. Check procedure
No
Yes
Is there a response from the indoor unit PCB?
No
Yes
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,
e h t e c a l p e r indoor unit PCB and
Check the communication
cable in each PCB
and replace the PCB
Yes
Is the power/communication
cable connected correctly?
No
Connect the power/communication
cable correctly.
outdoor unit PCB in order of mention.
cf.) If there is no oscillo scope, it can be replaced multimeter instead of osillo scope.