Chosen Solution
For the past year, my iPhone 4 locks up every now and then (it does not let me slide to unlock) but it always began to work again after 4 or 5 force restarts. A couple days ago, this happened, but it did not work after many force restarts. I restored it to factory settings, and I got to the part where it says to let your phone restart, but after it did, the iPhone turned off and now it will not turn back on. iTunes cannot see it and I have tried charging it and it does not work. It had iOS 5.1.
What happens when plugged into mains power? Your Battery main have just DIED or at best gone fully flat. Which can only be recovered by the mains power. Do you get a flashing red Battery symbol with a lightning bolt? Leave for 1 to 2 minutes to see if it gaining a charge and pull the plug. If it shuts straight off then time for a new Battery. You can purchase from here. iPhone 4 Replacement Battery - Does not require soldering I hope that gives you some direction.
I’m having the exact problem. Did you manage to find a solution?
im having the exact same problem . ive tried holding down the home and power buttons but it doesnt work
i tried reseting my jailbroken 4s. and now its not turning on…. help.<>,.,.,<>
hold power and home button while itunes it open and iphone is lugged into pc, it should work
