Today I went back to a job that I had installed six years ago. It was an external cat5 cable from the back of the router to the TV in the lounge so that the customer could get catch up TV. Everything had worked fine up until a few weeks ago when the customer took on a new service provider and at that point the cable stopped working. I had no idea what might have gone wrong as these hard wired installations are usually bullet proof. So I called in this afternoon and plugged my laptop into the end of the cable at the TV end, sure enough no connection. Then I got out my Peak cable tester and checked for continuity, pins 7 and 8 where disconnected. I reterminated both ends quickly and tested again with the same result! I checked the cable outside for damage and couldn't see anything obvious. So I grabbed two more Euromodules
and started to terminate them. At which point the customer mentioned that when he tried to get the new setup working he used a splitter. I didn't understand what he meant by that as splitters (or ADSL filters) would not be required on this setup. So he showed me what he had plugged into my Euromodules.
I have never seen the like of this before which made me think changing the Euromodules might be the solution so I pressed on with the Terminations. Sure enough I had full continuity when I next ran my Peak tester. After that everything worked again as it should. I advised the customer to throw out the 'Splitter' above and I sold him a 5 port switch which does the job of providing addional network ports with no fuss.
I'm alway intrigued why there was a problem so when I got home I took the offending Euromodules apart and took a look. Below you can see the effect of inserting the 'Splitter' had on the Euromodule. I seems to have bent the springs out of the way on pins 7 and 8 so no wonder I didn't have any continuity. So the 'Splitter' is now consigned to the bin, probably a sign of poor workmanship.