I previously tried the tftp recovery which did not work. It would take the file but do nothing with it.
I bought a cp2102 and followed the youtube video guide.
MOST of the time in putty it will pause at U-Boot and do nothing.
Rarely, it will go further.
I have never had access to the command line to enter tpl
/edit
It had 3 different boot cycles.
- hang at uboot 2) freeze at kernel 3) automatically stop after kernel but allow command access
It was a super rare chance for 3) to happen.
Flashing was unsuccessful and it will not allow command access anymore.
Assuming it now needs a flash programmer