User's Manual

Chapter 18 Maintenance and Troubleshooting
Resolving problems
SmartClass TPS User’s Guide
May 2014 22035456, Rev 001 157
Issue
I am receiving error indicators.
Resolution
Error Indicator counts indicate content problems, since the indicator can only be set by the encoder.
Typically this would affect only one program or channel. However, if a multiple program feed in the
head end is experiencing problems, more than one program/channel could be affected. Analyzing
a channel from another source, or different feed would be instructive. The video may show poor
quality with only the Error Indicator count showing a problem. Any count is bad.
Issue
I have significantly more IGMP latency on one channel than the others.
Resolution
IGMP latency measures the network's performance. Typically, IGMP latency would be similar for
multiple channels. However, if network topology and management place access to certain program
material farther back in the network, then differences could be experienced. If such a hierarchical
approach is used, then differences might be detected based upon which programs are accessible
deeper in the network. Testing multiple channels/programs to exercise this network design would
be useful.
Copper test problems
The following section addresses questions about Copper testing.
Issue
The Tip (A) - Ring (B) voltage is reading negative.
Resolution
The Tip (A) and Ring (B) test leads may be swapped. Check your test leads to verify that they are
hooked up properly.
Issue
The AC voltage test result from Tip (A) to Ground (E) is 5 volts and from Ring (B) to Ground (E) is
15 volts.
Resolution
Either Tip (A) is open or Ring (B) is longer. This will also be indicated by noise on the loop. Results
on Tip (A) to Ring (B) should be 0.0 volts. Tip (A) to Ground (E) and Ring (B) to Ground (E) should
be equal to each other. Anything else indicates AC signal interference and/or an unbalanced line.
Ringer voltage level can be checked by having the CO ring back on the line. Results should be
either 85 volts (older switches) or 105 volts (newer switches).
Issue
The DC volt measurement on Tip (A) to Ground (E) is 15 volts with the battery removed.
Resolution
This indicates there may be an open in the insulation drawing current from another pair.