Tel & Internet dual connection -Not working-Help

My dual connector which connects my telephone and cable for the modem does
not allow either to work if both are connected.
If I disconnect the modem the phone works
If I disconnect the phone the modem works
I did have a problem with my extension to another phone but I am now
directly connected to the socket which does not include the extension
Can anyone suggest what is wrong and what is the solution please
Regards
Blair Malcolm

"Blair" <(E-Mail Removed)> wrote in message
news:uBRK%(E-Mail Removed)...
> My dual connector which connects my telephone and cable for the modem does
> not allow either to work if both are connected.
> If I disconnect the modem the phone works
> If I disconnect the phone the modem works
> I did have a problem with my extension to another phone but I am now
> directly connected to the socket which does not include the extension
> Can anyone suggest what is wrong and what is the solution please
> Regards
> Blair Malcolm
>
> Further information
BT have checked the line and it is OK
Since my last message I have found that when both are connected I am able to
connect to the Internet after 3 or 4 goes at trying to connect.Up until then
I get a message"No dial tone"
But with both connected if I try and ring in via my mobile I get the message
"busy"
So it looks like my internet connection is causing the problem
Blair

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