Welcome to Justanswer.com, my name is ***** ***** I will do my best to assist you.
The first thing we need to do, Is get your nuvi where it will turn on normally. So lets focus on that first.
lets try a master reset of your nuvi. Disconnect it from your computer. Turn it completely off. Then, do the following.
Hold your finger on the bottom right corner area of the touchscreen, keep holding your finger there and start the Nuvi.. keep holding your finger on the screen until it asks you to reset all user data.
Tap yes and the device will be reset. will it start now?
Dustin S.Senior Technician and Network Switching Systems Operator / Maintainer.