20 - 30 minutos
iPhone 3GS could not charge. Screen was cycling between Apple logo reboot and charging symbol of death with red battery bar over and over.
Ran some troubleshooting: tried to charge phone over night, phone never held charge. Opened iPhone and detached the logicboard from the battery over 2 hours. Re-attached logicboard to battery. Could not start and gave the same symptoms of a dead battery.
Got on ifixit, youtube and several forums for installation and removal advice. Opening the iphone 3gs is not a daunting task as previously thought. Bought battery on ifixit for $20. Replaced battery and installed it. Voila! iphone 3gs lives again!!!! Thank you ifixit!