tomtom one v3 problem on engine start.

[atropa]

Have been using this happily for a year. Today switched it on, set my journey and then started the car engine (Volvo V70). The result was a series of vertical stripes on the screen which I could not instantly clear as the device would not switch off. Any ideas please?
I am hoping to remember to start the car before switching on if this is the thing to do.

 

[Martinho76]

Have you tried a reset?

There small hole on the bottom that says reset you can stick a paperclip in there to restart it.