Default KFJD no longer boots after i flash wrogn u-boot.bin

So i didnt check rename the u-boot.bin image properly. I flashed it to a Kindle fire 7 HD but it the image was for a regular KF.
Right after that the KFHD no longer boots.
Black screen, fastboot USB connected, but nothing on the screen.
Anything i can do to revive this KFHD.