When I spoke to BT they said they had done a line rest up to my property and all was good and indicated wiring issue in my house. Would this suggest otherwise? I have spoken to BT have engineer book but not until Thursday morning, another day off work required.
If the router doesn't work in the test socket of the MK3 (which we have established is the master socket) then the fault is either the router or external to the house. You have tried another router ergo the fault is external.
I have done that too. I work in IT, albeit not networks, so am pretty tech savvy. I am relieved it's not internal wiring. Shame I have to book a day off when the fault is external. Couldn't they just send the engineer to the exchange or box in the street? Do you work for BT?