Trying to recover MXIII G II S912 TV Box from what looks like corrupted/dead internal memory

I think what Adam was trying to tell you is that your box is not dead. You may well have faulty internal storage chip, where a part of it does no longer work, but, if enough works to get the boot process going, you can aim it at external media to run CE. When using USB Burning Tool, only select items to do with boot / recovery and see how you go