How to Fix a Kindle Fire That Stopped Unexpectedly
If your Kindle Fire stops unexpectedly or otherwise exhibits unusual behavior, first try rebooting the device. If you continue to experience issues after rebooting, perform a factory reset to reinstall the operating system files. A factory reset deletes all of your accounts, data and apps. However, you can replace your Amazon content using the Manage Your Kindle tool from your Amazon account.
To reboot the device, charge the Kindle Fire for at least 15 minutes, unplug the device from the charger, and then press and hold the Power button for a full 20 seconds. Use a stopwatch or timer, if necessary. When the time is up, press the Power button to boot the device back up.
2 Factory Reset
Charge the Kindle Fire for at least 30 minute before beginning the reset. Tap the “More...” option in the top menu to open the Settings menu, tap the “Device” tab, and then tap “Reset to Factory Defaults.” The Factory Data Reset confirmation box opens; tap “Yes” to continue. The original files are restored and the device reboots.