Originally Posted by bryanfeanor
searching i found this page where explain how to fix the hard brick, black screen no sing of life, cant post links so, search in google "new life for a dead Kindle fire hd, is in mascote..... can any expert try it and explain that to the rest of us,
A while back, I brought this question up to Pokey9000, the developer of FireFireFire and Firekit for the Original Kindle Fire. His exact response to me was...
When the OMAP USB boots, it first waits a bit to handshake with a host. If the handshake is successful, the host sends a small loader to the OMAP that then does some hardware init and handshakes again with the host to get a payload to shove into RAM. This loader is similar to x-loader in that it has to be small to fit in the SRAM of the OMAP, and does low level initialization like mux, clock, and memory setup. However it differs in that it replaces the MMC and FAT handling in x-loader with USB loading as there's not enough room for a generic x-loader that does MMC and USB.
On HS (fused) OMAPs this initial USB loader payload must be signed just like x-loader has to be for eMMC boot. If the payload doesn't have a signature that checks out, the OMAP halts until it's reset. This is enforced by hardware, so short of finding a sploit in the OMAP ROM code or a copy of Amazon's USB boot tools used in factory it's not going to work.
TL;DR not likely.
Considering his knowledge of bootloaders and low level hardware stuffs far exceeds mine, and the fact that he's been looking at this issue ever since the B&N Nook devices (maybe even longer), I have to assume he knows what he's talking about.
The information on the page at Mascote seems to contradict what Pokey9000 says because usbboot uses an a-boot(x-loader) instead of this not-so-typical USB loader mentioned previously. And the answer to whether or not the author was actually successful in reviving the KFHD using this method has been left a little ambiguous.
But, as much as it would suck for me to have been the d*ck that told everyone that it couldn't be done, I would LOVE to be proven wrong.
I'd say, if you have a hard-bricked KFHD, then I guess there's not much else you can lose by testing it out.