IPhone 4 won't turn on unless plugged into an outlet (won't work on PC,car,etc),and when it is plugged in this pops up? What's the deal? (More info in comments) : r/iphone
How to Force Restart an iPhone 4 - iFixit Repair Guide
Bring Your iPhone 4 Back Up to Speed with These 6 Easy Tweaks for iOS 7 « iOS & iPhone :: Gadget Hacks
4 Ways to Fix iPhone Won't Turn Off Issue
The Quick Fix for Most Problems - The iPhone Book: Covers iPhone 4S, iPhone 4, and iPhone 3GS, Fifth Edition [Book]
How to power off iPhone without power button? - YouTube
How to Turn On iPhone without Power Button -Iphone 3/4/5/6/6S & Plus - YouTube
Abroad | Turn off data roaming | Apple iPhone 4 S | O2 UK
Can You Turn Off the Internet on an iPhone 4?
HELP! iPhone 4 LED light won't turn off | MacRumors Forums
How to Turn Off or Restart an iPhone, 14, 13, SE, & More
How to reboot / restart Apple iPhone 4
Apple iPhone 4S - Turn mobile data on or off | Vodafone Australia