i also found an xda post saying you could use jtag to unbrick it.
i’m now at
How To Find Kcolo On Any Phone PCB To Fix Dead boot
- kcol0 is related to the volume buttons
- it can be found on any found on any phone
- the vol up and down pads have an inner and outer circle
- kcol0 is wired to the same side of both buttons, so it has conductivity either with both outer circles or both inner circles
- these are side buttons so leads may not look like circles on board
- it’s a little ambiguous, but i think the presenter may have been saying that only one side of the buttons is common, so that common side can be used as kcol0. uncertain.
- short kcol0 to ground to use factory bootrom to reflash
on xda it also said to insert a charged battery or it can bootloop.