My tomtom to go will not turn on. the green light

If you have an SD card in try removing that before you power up.

You may also want to try the hard reset.
Paper clip in the tiny hole by the card slot.

Push it in firmly whilst the unit is powered up (not too hard) for about 3 seconds then release
You may have to power down and then up again and even hold down the power button a little longer the first time you do this.