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please do the following steps,
1) Remove your Kindle from the charger if connected.
2) Press and hold (or slide and hold)the power button to the right and hold it there for 30 seconds.After the first 6 to 8 seconds, the screen will go blank, which is normal. Continue holding the Power button.
If you only hold the Power button to the right for only 5 to 10 seconds you'll just turn the unit OFF. So,you have to hold the power button to the right for at least 30 seconds.
After the 30 seconds, release the Power button.The charge indicator light will turn on after a few seconds.
It will reboot and it will work again.
Then Please follow the steps to update the card info:
Go to amazon.com
Log in using the email id and password.
Once you have logged in , Go to Manage Your Content and Devices.
From Settings, select Edit Payment Method below Kindle Payment Settings.
Select the desired credit card information, or add a new card, and then click Continue.
Enter the desired billing address, and then click Continue. You will be taken back to the Kindle Payment Settings page where you can view your edited 1-Click payment method.
Hope it helps. Please do reply if it helps.
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