我是因為修改輸入法時，更動system.db然後權限回復不正確，重開機後，就是開機圖示的無限迴圈。
我的症狀是，file system沒有正常載入，所以什麼事都不能做。
解決方式
1. 要能執行ADB，還需要fastboot
2. 需要SuperOneClick http://forum.xda-developers.com/showthread.php?t=803682
3. 需要fbmode，請把它下載後存到SuperOneClick的ADB目錄下 http://forum.xda-developers.com/attachment.php?attachmentid=833582&d=1325144494
4. 執行SuperOneClick，選擇root，如果你已經root，他會問你是否繼續，請讓它繼續root，然後住。
5. SuperOneClick卡住後，執行cmd並切換目錄到SuperOneClick\ADB，執行以下命令
adb push fbmode /data/local/tmp
adb shell chmod 755 /data/local/tmp/fbmode
adb shell /data/local/tmp/fbmode
adb reboot
等Kindle Fire重開後，執行以下fastboot命令
fastboot -i 1949 -w
fastboot -i 1949 oem idme bootmode 0x4000
fastboot -i 1949 reboot
等它重開完就恢復原廠資料正常開機了。
I was managed to brick for changing the system.db without writing back correct permission, after reboot KF, it loops at booting animation.
My situation is file system was not correctly mounted.
Here’s my solution
1. You need correct driver that can use ADB and fastboot
2. You need SuperOneClick http://forum.xda-developers.com/showthread.php?t=803682
3. You need fbmode, please download it to ADB directory of SuperOneClick. http://forum.xda-developers.com/attachment.php?attachmentid=833582&d=1325144494
4. Run SuperOneClick, click root, it will popup a message if you already rooted, click yes to move on and wait for its failure.
5. After SuperOneClick stalled, go to cmd mode and switch to SuperOneClick\ADB, run following command.
adb push fbmode /data/local/tmp
adb shell chmod 755 /data/local/tmp/fbmode
adb shell /data/local/tmp/fbmode
adb reboot
issue following fastboot command after kindle fire reboot
fastboot -i 0x1949 -w
fastboot -i 0x1949 oem idme bootmode 0x4000
fastboot -i 0x1949 reboot
Everything will back to factory value after reboot.