Оригинальный сообщение: Mark Prince ,
It sounds like to me that you need to change out the battery. Where did you purchase the phone? I am asking because if you purchased it second hand, off Ebay as refurbished or even from a carrier it may have a low quality battery in it. These cheap batteries to not contain the "gas gauge" function that allows you to check your usage (you should be able to check it at any percentage). If you are feeling froggy and want to change it yourself there are guides on this website as well as Ifixit videos on youtube on how to replace it. I would also purchase your battery from this website instead of Amazon or Ebay just to ensure you get a OEM quality replacement. One quick way to check and rule out your power management IC as you discussed is to turn your phone off, wait a few seconds and plug the charger in connected to the wall. If the phone boots up without pushing the power button then there is a problem with the IC, if not it is most likely just a dead battery. If you do not want to do it yourself you can take it to a local repair shop or use a mail in service to have it replaced and they can also troubleshoot it to ensure it is not the IC. Let me know if you have anymore questions. We typically do not talk business on here but I do offer a mail in service, you can reach me at this email email@example.com. Hope this helped!