In a moment of mental failure I did re-tune on this unit, as the usual message came up about new channels found etc. No matter what I do now, including a re-scan with aerial disconnected, I get no channels found and a grey screen. Is it time to accept that this unit has reached its sell by date?
Any help/thoughts would be appreciated folks.

Sorry folks but help eventually came via my ageing brain! After numerous goes at doing a factory reset/shipping condition I tried, with very little hope, a simple re-tune and, hey presto, its sprung back into life! A case of engaging brain(?) before opening you know what!