I'm pretty sure if the STB wasn't recieving a signal than the BB wouldn't have worked on the tech's laptop.
but I may be wrong!
Thanks so much everyone for all your help, it's been so frustrating and the downtime is affecting my ability to work from home.
It seems like everything possible has been checked and rechecked, I even called tech support for my PC, which is still under warranty, and they're convinced my PC is fine, NTL are convinced my line is fine, yet I still don't have net access
I really don't want to swtich ISPs, but I'm at the end of my tether.