And how are we going to tell that?
My first gues, is its a 5 year old phone, In the tech world, it's an antique. Time to upgrade. Maybe a dead battery, which you can replace off amazon, or the phone reached its terminal point.
poohbear6421, I'm so sorry to learn that your Note 4 won't power on. Mama23dogs may be right about the battery being dead. But we can also try to see if it will power on using an alternate power-up method. Please try this: https://www.verizonwireless.com/support/knowledge-base-122810/ Let us know if the phone powers on after those steps are completed.