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No, changing the cable company will not affect the Kindle Fire. This usually happens if the firmware is glitched. First we can can soft-reset the Kindle and see if it works or not. Press and hold down (or slide) the Power button for 20 seconds and this will reset the Kindle. Does it work now ?
Please let me know if that didn't work, so we can continue troubleshooting.
If it is not turning on, then connect it to your computer with the USB cable and then hold down the Power button for 20-40 seconds and this will force reboot it. Let me know if it still not working.