Thompson Sky + HD box stuck in standbye mode?

I have a Thompson Sky + HD box which will not come out of standbye mode, the red light when powered up is permanantly on. This began one day after it hadn't been used for approx 12 hours, I have tried another Thompson Sky + HD box wired up exactly the same and that worked fine, so it must be a fault on the box. Can anyone tell me if it is a fault or can I do something to boot it up !