In trying to install a custom bootloader on my Kindle Fire HD 7", I bricked it. When trying to start it normally, it shows "kindle fire" for a few seconds, but then the screen goes black and it becomes totally unresponsive. When I tried booting it with a factory cable, it shows "kindle fire" for a few seconds, and then switches to the "fastboot" logo, but again it is unresponsive. In both cases, my kindle is never found by adb or fastboot or any other utility when connected to my computer. I'm fairly certain this not a driver problem, because my kindle was recognized before, which is how I rooted my kindle. Is there anything else I can try to unbrick my kindle? The main problem is that it is never recognized by my computer. Now what?