/diy/ - Do It Yourself

>spend the last 2 weeks trying to fix the bad initial layers on one model of pic related
>context in last thread, character limit would not let me shove it all here
>finally notice one of the fans seems stiff
>replace it
>no change
>out of options
>remember an anon in here said to try updating the firmware
>fuck it, out of options
>spend several hours looking into how to do it
>carefully follow the process
>get it to build without any errors
>upload it to the printer
>it's now stuck in bootloop
>no longer recognized by the computer either
I'm sure somehow this is my fault, but exactly how screwed am I here? Trying to find how to access the thing in this state is not coming up with any relevant results so far, I downloaded its previous firmware version just in case anything went wrong but it's somehow gone so ridiculously wrong that I seemingly can't even put that back on now.

>two of the same printer
>put exact same gcode on both
>one comes out fine but the other comes out a complete mess at the bottom
What hardware-related problem can cause this? Trying to search about issues that look like this just gives me results about changing things in the gcode, but that's definitely not the problem here.