Make sure there isn’t any dust or lint in the power port.
Using the original power adapter and USB cable, plug your Nexus device into a functioning power outlet. Nexus phones and tablets have specific power requirements, and the USB cable and power adapter that are included are designed to meet those requirements.
Press & hold the Volume down button. While holding Volume down, press & hold the Power button for at least 10 seconds until you see an Android robot and the word Start on the screen.
Press the Volume down button until Power off is highlighted. Press the Power button to select that option.
Once your device turns off, disconnect the charger, then reconnect it. A battery icon should appear on your screen.
Charge your Nexus device for at least 1 hour before turning it back on.
I've tried all that before , it still never goes past the Google logo. I know im gonna have to factory reset it. Im just wanna find out if theres anyway to get files off of it before i do that.