Chasing a wierd problem

[KeepItSimpleStupid]

Telephone out. Test jack turned out to be bad, plus an inside problem. DSL didn't seem to be affected much.
Telco guy gave me a nice new combo DSL splitter, test jack, half ringer and a DSL friendly protector. Cool!

My problem to find out what's wrong inside. I had 24 VAC on the inside lines when disconnected from the telco. Not good, I suppose. This means I have to look for active devces: router, TV, telco handset base station, PERS alarm system and a modem.

OK, I think I have it narrowed down to a bad ground on a circuit: where:\ my router is, where an access point and antenna amp is, where a surge suppressor and an outside GFCI outlet are. There are a couple refrigerators on this circuit too, but I think their outlets could be OK.

Now here is the fun parts:

My router connects to the phone line. With that wire pulled, everything seems OK. Yea, I know, routers aren't supposed to connect to the phone line. Mine does, because I had dial-up wireless for a while many years ago.

The TV connects to the phone line. Not a set-top box, but the TV. This TV has a speaker phone built into it called a SPACE PHONE. Yep, TV's aren't supposed to connect to the telephone line and the SPACE PHONE light was on when the TV was flakey. Unplugging the TV power cord between uses usually made the TV unflakey. I thought it was a temperature thing. it could take a month or so to verify this.

I haven't connected the suspect device to see if the phone system wacks out again, nor have I moved the stuff to another outlet and connected the router to the phone line, nor have I fixed the bad ground. I THINK know where the bad ground is though.

I'm wondering how this is going to play out?

I could see some poor tech trying to figure this out.

 

[4pyros]

Sounds like the phone jacks on one or more of your peaces of equpment may not be properly isolated from the mains voltage lines. With a metter cheak for continuity between the AC plugs and the phone jacks on all the equpment. Andy

 

[KeepItSimpleStupid]

Well, the stuff plugged into the bad ground was temporarily moved to another outlet with a good ground and the telco device was plugged in. No issues so far. The TV signal seemed better too.

Issue still isn't quite fixed. I know there is a ground break. I just have to find it.

 

[JMW]

24 VDC? Should be 48 VDC maybe as high as 52. As for a ground, there should only be a ground at the entry point where the carbon arrestors are located.
I think you have a broken wire, or a device that is loading down the system.

 

[KeepItSimpleStupid]

The measurement was done with the phone line disconnected at the NID looking into the house side. That voltage could have been "phantom" due to leakage paths. That's one of the problems using a high Z meter to measure things. I did not put a 10K or smaller resistor across the line.

The inability to to dial-tone was found when my router phone line was disconnected. It continued to go away when the outlet strip containing, a router, USB server, access point, Ethernet switch, and an antenna amp was moved to a properly functioning outlet. A GFCI outlet remained at the end of the run.

Only the Antenna amp was 3 prong and the GFCI had a ground, so the ground (15 ohms) was probably made through the coax who knows where, but probably at a ground block.

An Ideal Sure-Test tester correctly identified the ground >3 ohms, but erroneously flagged the outlet as having the wrong polarity. This, I'm betting was due to other interactions and probably the result of the filters in the outlet strip. When the outlet strip was removed and the outlet tested that it was plugged in, it registered the open ground only and not the reverse polarity.

The affected circuit also has some motor loads (i.e. refrigerators)

It's not 100% fixed yet. I plan to replace a section of NM-B cable.