Troubleshoot your DSL Filter Setup

If there is a fault with your DSL Filters, or the way you have set them up, you may observe the following symptoms:

• line noise or echo.
• no dial-tone, or a flashing ADSL/Line/Internet light on your ADSL Modem.

These simple steps should help you determine where the fault might be occurring:

Line Noise/Echo on the telephone line 

1. Disconnect all of your ADSL equipment and DSL filters.  Plug a telephone directly in to your BT socket.  Do you still hear line noise? 
   Yes – contact BT to check your telephone line. 
   No – go to step 2.
2. Connect a DSL Filter to the BT master test socket¹, and then connect the telephone to the filter.  Do you hear line noise? 
   Yes – the DSL Filter could be at fault.  Contact support. 
   No – repeat with another DSL Filter.  If there is no line noise with any of the filters, go to step 3.
3. Connect your ADSL Modem  and a telephone to a DSL Filter at the master test socket¹.  Try each of your filters. Do you hear line noise? 
   Yes – the Filter may be at fault.  Contact support. 
   No – there may be a fault with your internal wiring.  Repeat steps 2 and 3, but from the extension socket or lead.

No Dial Tone

1. Disconnect all of your ADSL equipment and DSL filters.  Plug a telephone directly in to your BT socket.  Do you hear a dial tone? 
   No – try a different telephone.  If you still have no dial tone, contact BT to report a possible line fault. 
   Yes – go to step 2.
2. Connect a DSL filter to the BT master test socket¹, and then connect the telephone to the filter.  Do you hear a dial-tone? 
   No – the DSL Filter could be at fault.  Contact support. 
   Yes – repeat with another DSL Filter.  If you get a dial tone with both filters, go to step 3.
3. Connect your ADSL Modem and a telephone to a DSL Filter at the master test socket¹.  Try with each of your filters.  Do you hear a dial-tone? 
   No – The DSL Filter may be at fault.  Contact support. 
   Yes – there may be a fault with your internal wiring.  Repeat steps 2 and 3 from your extension socket(s) or lead.

ADSL Modem does not synchronise

Synchronisation should be indicated on your ADSL Modem by a light labelled ADSL, Line or Internet (I).  Power down your equipment for 30 seconds and power back up before beginning these checks.

1. Ensure all of the physical connections between ADSL Modem, DSL Filters and BT sockets are secure.  Check that all telephony equipment is filtered and the ADSL Modem does not pass through more than one DSL Filter.  Can the ADSL Modem get synch? 
   Yes – the wiring was at fault. 
   No – go to step 2.
2. Unplug all telephony devices so only one DSL Filter is plugged in to a BT socket.  Connect the ADSL Modem.  Can the ADSL Modem get synch? 
   Yes – the wiring or other DSL Filters may have been at fault.  Check with your other filters.  
   No – swap the DSL Filter and try again.  If you still can not get synch, go to step 3.
3. Move your ADSL equipment to the BT master test socket¹.  Can the ADSL Modem get synch? 
   Yes – your internal wiring is faulty; contact BT or a qualified service engineer.  
   No – your ADSL line may be at fault, contact support.

¹IMPORTANT NOTE: The master test socket can be found by removing the faceplate of a standard BT NTE5 socket, please see Related Article for illustrations. If you do not have an NTE5 socket, you will not be able to eliminate your internal wiring from being the cause of your connection issue.  We recommend that you contact BT Retail to have an NTE5 socket fitted at your premises.