Perform a Quiet Line Test |  |
Step 1
Plug an analogue phone into the main BT test socket.
Step 2
Dial the test number 17070, Choose option 2 from the menu "Quiet Line Test"
Step 3
If your telephone has the option, put it on mute. you should hear nothing through the handset.
Step 4
If you hear any line noise, crackling, buzzing, popping or humming note the time you conducted the test.
