try this :
[Please Register or Login to download file] is in spanish , but is simple mantain star button , to off tomtom , after mantain buton to see black an white letters , aftes se this , release and push again to se the next screen recovery mode now you can conect to computer an iniciate my drive , after these need to repair your tomtom , if this method not repair , call to ask for tomtom assistance to reset from his servers