The Amazon Kindle is known for having several firmware issues, and it is not unusual seeing the unit freezing and not starting.
To start you can attempt doing a soft reset. To do a soft reset
press and hold the <ALT>, <Shift>, and <R> keys
simultaneously. The Kindle display should go blank for few seconds, and then
If your Amazon kindle is still frozen, try resetting the unit to factory default settings with the hard reset procedure below. Procedure is different, depending on the Kindle model.
All you have to do to reset the Amazon Kindle 2 and Kindle DX is pressing and
holding down the power button for about twenty seconds, then release
the button and let the unit restart.
If instead you have the previous model, the amazon Kindle one, then you
will need to open the back cover by pressing it and sliding it to the
right with your finger, same as when you have to replace the batteries.
Behind the cover you will see the reset hole switch.
Push and hold a sharp pointed object, like a paper clip, or the tip of
a pencil inside the hole button located under the battery cover.
Wait about ten seconds until the Kindle restarts and resets to default settings.
The last procedure and the picture below refer to Kindle one only. If you have kindle two, then please use the first procedure.
If the above does not fix the problem, then the unit is faulty. In that case contact Amazon to get support.