Not just faceplate problems. if there's a wiring fault on any VDSL extension, that will also cause problems.
Yeah, that's why the ISP normally say to remove all face plates and to use the test socket.
And if it still has a fault then its "most probably" an external fault.
I replaced the entire NTE5a Master Socket and wiring (apart from BT's cable to the first box to the Master socket
) due to it being a very old one like 15 - 20 odd years (back in the days of Home Choice), am currently using the xDSL MK3 (ADSL, VDSL) face plate and I have used CAT5e on it's 2 pin IDC connector from downstairs to upstairs in the middle of the house which works great, same with all the phone extensions are connected to the IDC connector on the phone face plate, makes it very easy to locate a fault on either wirings.
Image of NTE5a Master Socket + xDSL Filter
Edited by PaulKirby (Wed 15-Apr-15 21:10:03)