Gave up the ghost yesterday, won't turn on any more. Have tried everything listed on Microsoft's help webpage including the hard reset etc.
I've had it plugged into a computer all day and twice 'unrecognised USB device' has popped up! But only for a second or two.
Spoke to Microsoft, it's out of warranty by 3 months, so... replacement is the only choice, at a cost of £90! Can get 'B' grade secondhand ones off eBay for £45 so I think I'll probably just do that seeing as though Microsoft can't actually guarantee getting a brand new replacement! Could end up with a Band 2 if there's no stock I suppose, but not sure it's worth the risk.
Has this happened to any one else?