Bt headscratcher

[Eddiesparks]

Went to do some work in a large flat - extra sockets on a radial, few extra lights, chandelier put in etc. we disconnected a (not used) secondary bt point for chippy as it was in a cabinet that was being rebuilt. Twisted wires together that were together in the socket. By the way there's 2 separate bt lines. One they use and one they dont, used to be hooked up to fax machine, now not used. The sec. socket was on the line they didnt use. I find the master for the unused line. Works fine. All wired in newer twisted pair cable.

Following so far?!

I then find out the line they use is not working after our works. We didnt touch this line. It consists of just a master (not net5 test master style - looks more like a sec. socket but had capacitor on it so must be master? I may be wrong??!) and no secondary sockets. One blue one white going to 5 and 2. (older style cable not twisted pairs) - what the hell is going on?!?! It must've been us but i cant see how...?! Ps i tried 2 different phones and had no joy. Also there wasnt 48v across any of the cores. No signal?!

 

[Richard Burns]

Find and trace the incoming BT cable for the in use line and test the cable at the start (which should be the in use master socket) but if it is not then find out where the master socket is and check all the connections.

If the other unused line is coming in differently then make sure the outgoing cable is disconnected.

 

[Silo]

Youve probably missed a joint somewhere where the two share a cable!

 

[UNG]

Did you check both lines were working before you started?

You have two lines one working and one not have you verified the phone number of the working line or are you accepting what the customer is telling you, you could be chasing a non existent fault

 

[Eddiesparks]

Hold on am i being really stupid?! Can you get 2 lines from one incoming cable? I just assumed different cable for different line. Am i wrong?!

 

[Retrosparks]

Hi, each incoming BT line is only a pair so it is common for a property with more than one line to share a cable, pair one being blues, pair two oranges, pair three greens and pair four browns.

In properties fed by overhead drop wire, the practice is also common, orange and white being the first pair and black and green being the second.

As Richard has said, I would trace the cable to where it enters the building and start from there looking for 48-50 Volts on the good line.

Good luck !!!

 

[UNG]

Hold on am i being really stupid?! Can you get 2 lines from one incoming cable? I just assumed different cable for different line. Am i wrong?!

Plug a phone into the good line and dial 17070 if CLI is blocked dial 1470 17070 this will give the phone number of the line you are connected to if the dead line is the line you need you will have to contact BT for a repair and will probably be hit with a charge

 

[7029 dave]

you only get 50v when circuit is ringing.

 

[7029 dave]

go to the box you disconnect lines are in prs ie pr 1 whit/blue whit/org etc ring the number out then short each pr out when you get the pr is will hang up. that will be your main line.

 

[DPG]

you only get 50v when circuit is ringing.

Nope. Daz

 

[UNG]

When a phone is ringing the line voltage could be 100v or more

 

[Silo]

When a phone is ringing the line voltage could be 100v or more

Not when i used to install PABXs, it was always 50v (sometimes peaking to 60v) when ringing.

 

[Silo]

I've just checked and it seems things have changed since these old bones used to install telephones, it used to be 50v on hook & ring to 20v off hook (or there abouts), it seems that now it's nominal on hook at 48v ring at up to 85v and off hook as low as 6v!!!

I guess thats what you get for not being in the game constantly!

 

[Eddiesparks]

When i ring the line that i am havimg probs with i get the 1571 'this person is on the phone' message

Also, like i said the master which is not working is the only point out of three in the house to have non twisted pair wiring, older style i think. And it's NOT on an external wall. The wall it's on backs onto another flat. Not very BT is it?!

 

[Eddiesparks]

This makes it v hard to trace to the street!!