Tomtom Screen Protector I Have Lost My Tomtom 710 Screen,s Light.?

I have lost my tomtom 710 screen,s light.? - tomtom screen protector

Hello, my tomtom 710 worked well for the first year, but has lost the light of the screen. It switches on / off well and can play in Manu, but no clear opinion. I finished in the brilliant Manu, but to no avail, no damage to the screen at all. Now the problem is that no repair tomtom, s in Cardiff.
Please tell me if anyone of this problem, I thank you know.