My faithful old TomTom One 3rd edition SatNav is, I admit, getting on a bit, but I've sort of got used to translating the distances from Roman numerals and following instructions from Boadicea. Anyway, its battery packed up the other day, so I bought a replacement battery, and a replacement TomTom One 3rd edition just in case. I've charged the new battery up with the new SatNav, checked it works, then transferred it to the old SatNav. Problem is, when I switch the old one on, it does the TomTom jingle but nothing appears on the screen. Before I list the old one on eBay for a piddling sum as 'spares or repairs', has anyone else had this problem and solved it, or is it just plain knackered?