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Standard User spiteri
(fountain of knowledge) Sat 13-Dec-14 12:54:34
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Need some help understanding BT extension wiring


[link to this post]
 
Hi all,
I've just moved in to a property and have some issues with the BT Infinity (DSL drops when the telephone is hung up).
This has been diagnosed as being related to the extensions, even when they've nothing plugged in, as the problem is gone when the test socket behind the master face plate is used.

There is 1 master socket in the kitchen and 2 extension sockets.

I've looked behind the master socket and it appears to be as I'd expect.
2 white cables with only 2 wires used from each.
One cable connects to the A/B connectors, so that's the BT entry point.
The other connects to the extension points on the face plate.
http://i.imgur.com/GtZuB6c.jpg
That looks ok.

Behind the extension sockets are also 2 wires. They are both hooked up the same. I can only presume one of them is the cable back to the master socket extension and the other runs to the next extension socket?
http://i.imgur.com/cfO2nEQ.jpg

Can somebody verify this looks ok?
If so, my only question is why the 2nd extension has 2 white cables coming in to it? You'd think it would have only 1 as there is nowhere else for it to be going....


Does anybody have a strategy for how I should proceed to start solving this? To be honest the latter extension (if they are hooked in the serial way I'm imagining....) could be disconnected.


Cheers
Paul

Edited by spiteri (Sat 13-Dec-14 13:55:26)

Standard User RobertoS
(elder) Sat 13-Dec-14 13:50:02
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Re: Need some help understanding BT extension wiring


[re: spiteri] [link to this post]
 
We need a little clarification about the master socket assembly smile.

Is an Openreach VDSL2 filter fitted, as in the picture on this page, or is it just a normal faceplate with just a phone socket and you are using a dangly filter?

If there is a VDSL2 filter, is that where the A/B connectors are, or have you also removed that - revealing the test socket - and then removed the test socket to get to the A/B terminals behind that?

If there isn't a filter as in the picture, when you say you have looked behind the master socket, do you mean just behind the faceplate, where you can see the test socket, or have you also removed the test socket assembly.

Re the extension wiring, we need to know what colour the T2 and T5 wires are at each connection point. T2 should go to T2, and T5 to T5. Swapping them is wrong, and there is also a chance that the "pair" is split anyway. Particular colours go together as pairs and not using a pair is very bad.

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Standard User spiteri
(fountain of knowledge) Sat 13-Dec-14 13:54:03
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Re: Need some help understanding BT extension wiring


[re: RobertoS] [link to this post]
 
Thanks for your reply.
There is no openreach VDSL2 filter. I have one in the mail, however.
It's a normal faceplate currently, with a dangly filter.

I briefly unscrewed behind the test socket to observe the A/B connectors. I've put that back as I'm happy with the state and shouldn't be dealing with back there anyway.


I'll get back to you on the latter part.

Edited by spiteri (Sat 13-Dec-14 14:07:18)


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Standard User spiteri
(fountain of knowledge) Sat 13-Dec-14 13:57:38
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Re: Need some help understanding BT extension wiring


[re: RobertoS] [link to this post]
 
I've fixed the photos in the first post. oops! That should help some.

I've checked the wires and the T2 and T5 colours are matching on all ends.
Administrator MrSaffron
(staff) Sat 13-Dec-14 14:50:31
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Re: Need some help understanding BT extension wiring


[re: spiteri] [link to this post]
 
A good chance the VDSL2 faceplate may help you, a case of waiting and trying

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User jamie543
(regular) Sat 13-Dec-14 14:52:10
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Re: Need some help understanding BT extension wiring


[re: spiteri] [link to this post]
 
From what i can see the extension sockets are daisy chained off each other and the extension socket seems to have some sort of capacitor could this not be cuasing the issue?

Standard User RobertoS
(elder) Sat 13-Dec-14 15:36:48
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Re: Need some help understanding BT extension wiring


[re: jamie543] [link to this post]
 
The pictured extension is certainly a master socket - one of these. I believe that's not normally a disaster, but is certainly not recommended. If the second extension is the same then I wouldn't like to pass judgement, except both should be LJ2/3As.

The orange and green pairs seem to have been disconnected at the master.

I suspect from the OP there is at least a third extension somewhere.

My broadband basic info/help site - www.robertos.me.uk | Domains,site and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 56.4/14.5Mbps @ 600m. - IPv4BQM IPv6BQM

"Angels can fly because they can take themselves lightly." - G K Chesterton.
Standard User ian72
(eat-sleep-adslguide) Mon 15-Dec-14 08:37:37
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Re: Need some help understanding BT extension wiring


[re: jamie543] [link to this post]
 
Quick question - do all the extensions have a ring tone when you plug a phone into them?
Standard User MHC
(sensei) Mon 15-Dec-14 11:13:28
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Re: Need some help understanding BT extension wiring


[re: spiteri] [link to this post]
 
Convert the downstream socket to a real secondary - cut out the capacitor, sparkgap and resistor.

Remove the additional "unused" set of connections especially if you don't know where they go.

Technically, it should be Blue/white to 5 and White Blue to 2 however having them reversed will not cause an issue.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User spiteri
(fountain of knowledge) Tue 30-Dec-14 10:12:05
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Re: Need some help understanding BT extension wiring


[re: MHC] [link to this post]
 
Everybody - thanks for the replies.
I've got it sorted - I started by replacing the master socket with the latest and greatest. I disconnected the extensions and just ran like that for a while - it worked perfectly.

Then I connected the extension to the VDSL extension connector (not the typical extension connector, which I think is for phone only with this faceplate). Unfortunately the problem returned, so, I ordered 1 replacement extension faceplate which is much simpler looking - no big capacitor etc. like MHC mentioned.

I've established that the socket I need is the 2nd in the chain, so I've hooked up this new faceplate and not connected the further extension as it is not required. Also disconnected it on the other side to make sure + disconnecting the unknown cable.

Plugged it all together, perfect now! Modem in the correct place, great speeds, no disconnections.

http://www.speedtest.net/my-result/4020070952

Thanks all for your advice - all very helpful!
Paul

Edited by spiteri (Tue 30-Dec-14 10:13:06)

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