How do I power on my samsung Galaxy tab 2 7.0?

I have a galaxy Tab 2 7.0 (very old, as you can tell) a d I plugged it in to see if it would turn on because there was some stuff I needed to get off of it. It turned on and charged to 100 but every time i try to turn it on it brings me back to the 100% battery icon. how do I fix this?