Try www.goodmans.co.uk ask what cost of repair etc is.
Compare repair cost against buying a new Goodmans with basic mapping and transfer your maps to it, you might find its better to have a sat nav with full warranty than short, usually only 3 moths, repair one and a repairs sat nav which might go wrong shortly after as they will only warrent their repair.
But before buying the new make sure that you can trasfer your maps to the new one. I am guessing you can unless the orginal supplier of the map has a transfer block on it.
hope this helps.
Bob, June 2011