I have same issue, the TV Box not boot with any image. I'm trying every thing.
In may case, i'm using SD Card to flash new image, everything I did as proceeding sad, but in the first boot the led start blink yellow/orange during hours and not boot.
I try to recovery, and every thing is ok, so the board boot in native firmware.
I try to boot using LibreELEC and it's boot too.