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BT Master Socket 1990's type showing test socket

BT ADSL Face Plate for Broadband Connections

BT NTE5 mk.3 used for Broadband & Fibre Optic Connections

Difficulty Making or Receiving Calls?

If you’re having difficulty making or receiving calls on your landline, then it could be because of a problem with the network. As part of your contract with them, if the fault is on the BT/TalkTalk/Sky/Plus Net or other telephone network, they will send out a technician to fix it if you authorise a possible call out charge. 

If the fault lies with the network externally, you will not be charged but if the fault is on your own wiring or equipment you will be charged for the call out. So it is worth carrying out a few simple checks just to work out exactly what kind of problem you are dealing with. 


No Incoming Calls/ No Ringing?

  • Have you checked that your ringer is on? The ringer switch may be on the underside of the phone, in which case it may have been switched to the ‘off’ position accidentally. Once you have found the switch, try calling your own number from a mobile with the switch in each of its two positions. 

  • If you use a cordless phone, is it properly charged? Check the battery indicator, if there is one, and that the charger contacts fit neatly to the phone. 

  • If you have more than one phone in your house, are they all on the hook and ready to receive calls?


Unable to Dial Out or No Dial Tone?

Do you have a dial tone on the line when you lift the handset? 


No dial tone could possibly indicate a dead line and therefore a network fault. In which case you need to check the master socket following the instructions listed below:


Or is the problem consistent across all the telephones in your property? If only one of them is affected and not the others, then its more likely to be a problem with that connection or handset than with the network. 


If you use a different supplier than BT, try dialling out using the prefix 1280. This prefix will automatically route the call via the BT network and you will be charged at normal BT rates for the call. It will however prove that the phone line is OK and the problem lies with your providers network rather than BT’s. In this case you would need to contact your telephone service provider to arrange a repair. 



Noisy, Faint or Interference on Phone Line? 

  • Is the problem apparently only on calls to, or from, one particular number? If so then it’s quite likely that the fault is on the other number, not yours.


  • If you're a broadband customer, are you using a micro filter for every piece of equipment on your line, including phones, TV digi-boxes, games consoles or faxes? Micro filters cut down the sound interference that sharing a phone line with a digital device can cause. 


  • Are you using a cordless phone? Try attaching a phone with a cord to the socket. If, having done this, you no longer hear noise on the line, then the problem is more likely to be with your cordless phone than the network. 

How to Check a Master Socket if no Dial Tone or Broadband Signal Present

1. Unplug all the devices from your telephone sockets. 

So that you can test the line independently from any equipment attached to it, you’ll need to disconnect anything you have plugged into any of the phone sockets in your house. This includes telephones, faxes, PCs, modems, satellite television or digi-boxes, extension leads, adapters or double adapters. If you have broadband, don’t forget to unplug any micro-filters and your ADSL modem/router too. 

2. Test your main socket. 

Find your main socket. It’s usually located where the line enters your property. Test it by plugging in a telephone with a cord. 

3. If you have no problem at the main socket. 

If the corded phone works alone on your main socket, then it’s quite likely that the fault is with a piece of equipment and that your line and extension wiring are OK. To isolate the faulty piece of equipment, try plugging them in one at a time, checking the line again after each piece that you add. If you find that plugging in one particular piece of equipment causes the problem to recur, unplug it and consult the manual that it was supplied with, or contact the manufacturer. 

4. If you still have a problem at the main socket and it has a horizontal bar across the front plate (figure 2) please follow the instructions. 

If your main socket has no horizontal bar, like the one shown in figure 1, please skip to step 6. 

Carefully unscrew the two small screws on the face-plate of the main socket and the bottom half of it should pull out. Behind it, on the right hand side (see picture), you should see the test socket. This connects directly to the telephone line, bypassing any extension wiring you have. 


BT Master socket with Test socket.

1) Remove lower front screws then gently ease the front plate towards you. 

2) Plug a phone into test socket and listen for dial tone/make a call.

3) To test a broadband router plug {via micro filter} into the test socket.


If your corded phone now works normally when you plug it into the test socket, then it’s quite likely that your internal wiring is faulty. You can either attempt to repair the wiring yourself, or contact a telecoms maintainer (you may be charged for this repair).


5. If there’s still a problem at the test socket or the main socket. 

If you find that the line still doesn’t work there may well be a fault with the network or wiring. In this case, you need a technician to check your wiring circuit so please contact us on one of the following numbers.


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