How do you diagnose Tomtom One problems? Mine stopped turning on?

After a year of great service my TomTom suddenly won't turn on. (The charging light does shine when TomTom is plugged into the car charger.

I tried charging for 6 hours, pushing Reset for about 20 seconds, then pushing the On button for like 10 seconds.

There is a way to change the battery, but I hope to figure out whether a new battery will help before spending $20.00 to buy and try a new battery.

Harriet