My kindle screen recently cracked. I didn't really mistreat it more than any other device I owned, just that the kindle screen is very fragile I guess.
I contacted amazon support on the off chance they could do something.
The CSR asked me to power off /power on the device to see if that fixed the problem. I did what he asked and unsurprisingly the screen was still cracked after the off/on cycle.
At least I thought it was amusing.
