Your Kindle Fire includes a battery that provides power to your device, but just like with a smartphone or notebook computer, the battery doesn't last forever. If your e-reader won't turn on, the first step is to charge the device for a few hours; if that doesn't work, a hard reset may be required.
Charge Your Kindle
To charge your Kindle Fire, connect the smaller end of the USB cable to the tablet and then connect the larger end of the cable to your computer or power adapter. If you've connected your Kindle Fire to your computer, confirm your PC is turned on and awake. Wait at least an hour before attempting to power on your device.
Do a Hard Reset
If the Kindle Fire won't turn on after charging, perform a factory reset on the device. Press and hold the power button for at least 20 seconds to erase all of your data and restore the e-reader to its initial condition. Press the power button again to turn on the device. If nothing happens, you likely have a hardware issue with your Kindle; contact Amazon for further assistance.