iPhone completely dead, shows no signs of life
My friend gave me an iPhone 3GS, he said he managed to get it to boot (not sure if he actually did!) however I’ve found that when plugged in (even overnight) it’s showing no signs of life, the screen is black and there are no sounds or vibrations whatsoever.
I’ve taken the device apart and measured the battery voltage, this was 0.16v so completely dead. I though this could have been the issue so to resolve this I remove the battery and charged it up using a bench power supply, it’s now reading 3.76v. I’ve reinstalled it into the phone but still nothing. (Maybe this voltage is still too low as even with the battery installed testing the battery probe points suggests it’s not charging)
I’ve checked what I believe to be the fuse for the battery and this has continuity, and I’ve checked to see if I have 5v on the dock connector motherboard test pads which I do.
I also checked to see if the dock connector voltage was present on the battery terminals, it doesn’t seem to be, could this be because the iPhone does not detect a battery?
I have also found that even powering the iPhone with no battery (through the dock connector) using an iPad 10W charger the iPhone shows no signs of life.
I have ordered a new battery, dock connector and digitiser. The digitiser is cracked but I’ve tried the phone without it to check it isn’t shorted. What are the chances of replacing these components fixing my issue?
does the iPhone need to detect a voltage above 3.7v before it will start?