Chosen Solution
Hi! You’re gonna have to boot to recovery mode in case of a boot loop. While it’s off, hold the power key and volume up. You will be prompted to Recovery mode. Use volume to scroll and power to select. Try wiping cache partition. Then reboot. If that doesn’t work, try the same steps, but instead factory reset. If that doesn’t work, then you should definitely get a replacement.
I had this problem, so I prised it apart expecting to remove/renew the battery. Inside I discovered the works were retained by 8 tiny steel screws. To keep these safe I decided to store them, on a strong magnet. Starting at the bottom right corner as I brought the magnet to the screw the Kindle immediately stopped malfunctioning. I tested all operations and everyone worked properly and without the sluggishness which had developed over the previous year!! Try this method without prising apart. Start at 4 ( of the clock) and move anti-clockwise. Share the result!!!