have a look here....
BBC HD and BBC ONE HD Stopped working no signal to be found .i did a scan and still not working ,anyone else having this problem.
deeman hope u havnt still got a black and white tellie !
but the fact remains that the transponder details were changed causing the problem , and the solution is a retune using the details provided in that other thread , like I did last friday after coming back home from my hols
the trick is to search the forum for answers to the problem , as its probably already been spotted and addressed by eagle eyed sat enthusiasts and hobbyists