Aporte original por: valkyrie455 ,
I see this alot with phones that have been cleaned and bad parts replaced but wont fully boot. Sounds like the power management IC could have burned out or there is still corrosion somewhere under the shielding near it that you may have yet to clean. Another thing to try is to boot the phone with a different combination of the cables plugged in (e.g : everything plugged in except for the power ribbon). If its the pins on the battery connector itself your best option would be to install a new connector on the board provided the solder pads are still intact and you know the pins are not being inhibited by corrosion damage.