broadband disconnecting on bright box 1 router when using the landline phone

[rogera1]

Discovered a new problem today. When picking up the landline phone handset the router starts to flash amber on broadband lamp (2nd lamp down) and internet is disconnected. Replace the handset and connection is restored and lamp returns to solid green. Any ideas? Thanks, Roger.

[Mustrum]

@rogera1  That phone was from before the time a plug and socket was used was it not?

Does it still have terminals to connect to the old style BT/GPO phone connector, or has it been modernised - if so how?

This is where pics may have helped a lot.

[rogera1]

Oh no, it was state of the art in its day. # key lower right above MR key. See the pic below :  

[Mustrum]

Ah yes, I remember them, but is the wiring connections that are the ones I would like to see.

Does bring back memories though!!

[rogera1]

What, you mean the internal wiring?

[XRaySpeX]

No, the wire that connects to the BT wall box.

[rogera1]

It's just the standard connecting cable that inserts into the Openreach 5C Master socket (or the original BT socket as was).

[rogera1]

Just to keep you'll updated, I have now connected a new corded handset to see whether the diagnosis is correct (yesterday). Will advise. So far OK.