I don't understand how the power cut would have affected it? unless you were charging it or it was connected to yr pc etc?
If you don't get any help from the forum, I'd advise you to visit the Advanced MP3 store in Edinburgh, ocean termninal. Normally I'd recommend them at Buchanan Galleries but they've suddenly upped and relocated elsewhere and I'm not entirely sure where

They're brilliant when it comes to advice for problems with yr mp3's etc cos they're not like Curry's and that who'll just focus on selling you a newer model.