Hi, I'm Randy. Welcome to JustAnswer. I'm reviewing your question now, and will post back with your reply ASAP.
This could be a firmware issue.
We will need to rule out the possibility of a firmware issue by resetting the software, using a force reset method while USB charging. If this fails then there is an hardware issue on the device that software troubleshooting can't resolve. Try these steps please>Connect the usb charger to the kindle and a wall outlet charger. Then Slide or press and hold the power switch for 40 second, then release. Wait 15 minutes then power on and check. If that fails and you are sure that the charger is working properly then that means the kindle has a hardware failure.
Did that work for you?