Default [Q] Limbo

My fire won't boot.
TWRP shows error when trying to flash new ROM : error flashing zip.
When rebooting it shows SuperSU is not installed and when I try to install with TWRP it locks on boot mode.
KFU is unresponsive when using option 2(root and superuser).

I've tried different ROMs, cables, and PCs.

Any ideas?

Thanks.