If all else fails and the box won’t come out of standby, there is one last resort that will reformat the hard drive and lose all your recorded programmes, but this has worked for me a couple of times. Note you need to press the buttons on the box itself, not the remote.
1) Switch off the box at the mains
2) Whilst holding down the left and right arrows on the front of the box (either side of the Select switch), power on the box. After a second or two, the Sky 'ring' will light.
3) hit the 'Select' button on the front panel - this will reformat the drive and reset the box. This can take a few minutes and the ring will 'whirl' backwards to show it's working.
Full credit for this from this website
http://www.avforums.c...y-fixed-solution.html