I'm not sure if the crap on the board is from where you reballed and got flux everywhere or something else but drop that into the ultrasonic - lets clear away the obvious residues as indicated by your fingerprints ;-)
Discard first software and SSD issue.
Disconnect internal SSD and boot with USB macOS.
Run corresponding EFI ASD and see if any error pops up.
Do PRAM reset 2-3 times, just in case.
Fan should go to max if trackpad is disconnected.
If spins to max with trackpad connected, there is a problem with a temp sensor from trackpad board.
Machine goes slow to, in such case.
Try known good trackpad flex/board.
Hello friend, the keyboard is shorted, it replaces, I restarted the PRAM 3 times, but nothing has changed. Replaces the U6100, for not having a recorder to perform ME cleaning of the BIOS region, in the tests that continue with the 8.4v PPBus, do you think it may be an internal failure in the SMC?
If you plan to work with Apple stuff, get Medusa programmer.
However, you will still need a classic USB programmer, as sometime need to upload BIOS file from PC to Medusa.
CH341 is the cheapest option.
TL866C, EZP2019, Mini Pro, many other options available...
thank you friend, I am researching Medusa, and there are 3 types which you indicate, and I also noticed that you need CH341A to read or put ROM in MEDUSA:
another question with Flash Spi Ch341a I can already clean the ME region, but would MEdusa make the job easier?
Using normal BIOS programmer, you can only read/write the chip; eventualy onboard, using proper adapter.
However you MUST clean ME region in other PC.
So you need read (remove, if necesarry) BIOS chip, upload to service PC, clean ME, and write back to the chip (resolder, if needed).
Medusa can directly clean ME (and more things can do) on the MacBook board.