Shorted hwfly CPU flex cable, now black screen after Nintendo logo

As mentioned in title, during a picofly installation in my switch lite, i very much stupidly soldered a wire to the CPU flex to most of the pads on the end of the ribbon. I knew you were supposed to only solder to either of or both of the two middle pads, but idk why in the freaking world i thought it’d be ok to allow the solder to touch the adjacent pads as well. I thought nothing would happen and the adjacent pads were useless, my ignorance cost me. I turn on the switch and smoke comes off the end of the CPU flex ribbon, so hot that it melted the solder and removed the wire i had soldered to it. Now, even with everything removed, switch boots to a Nintendo logo then permanent black screen.

What did i do by doing that? I have an extra lite board i can get parts off. Is it even fixable?

Probably fried the APU / RAM is my guess, may have got lucky and took out a second stage regulator. Do you have any shorts showing now, have you tested for voltages along the common rails to see if they’re coming up. You have a lot of probing and work to do here, but IMO you are now the proud owner of a donor board.