Kindle fire won't turn on at all

Hello l. I don't know if this is the right place to post this but here goes. 2 days ago , my kindle fire HD 7 5th gen updated to OS 5.1.4 on its own and now I cannot root my device, so I went on YouTube and watched rootjunky's firmware restore and unbrick video so that i can learn to restore my tablet to 5.1.2 so that i can root. I did adb sideload and then the video said to unplug USB cable and press power button, so I did. And then after my tablet won't turn on at all. I tried charging it for an hour and pressing the power and volume bottom for 30 seconds and it still won't turn on. Does anyone know what I can do? Is there a way I can fix this? Please help me