Troubleshooting
Samsung Electronics
4-5
4-3 Troubleshooting by symptoms
4-3-1 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 fro
m
the indoor unit PCB?
No
Yes
In this case, is the
voltage wavefor
m
between the lines square
wave with a
m
plitude over ±0.7V as shown
in the following picture?
+0.7V
-0.7V
Good
Bad
Check the co
mm
unication cable and
replace the indoor unit PCB?
Re
m
ove the co
mm
unication cable
connecting the outdoor unit to indoor unit,
and
m
easure 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 co
mm
unication still doesn’t work,
e
h
t
e
c
a
l
p
e
r
indoor unit PCB and
Check the co
mm
unication
cable in each PCB
and replace the PCB
Yes
Is the power/co
mm
unication
cable connected correctl
y
?
No
Connect the power/co
mm
unication
cable correctl
y
.
outdoor unit PCB in order of
m
ention.
cf.) If there is no oscillo scope, it can be replaced
m
ulti
m
eter instead of osillo scope.
