I have been using an iPhone 4S for the most part of last year. I make it a point to keep iOS, which is the OS running on it, on it updated to the latest stable version. I am only a little hesitant about upgrading the OS as soon as there’s a newer version available. I used to be more suspicious of applying updates, say, a year ago, where I would wait it out, lurking on forums and Internet looking for people complaining about unsavoury experiences with the update or critical and/or annoying bugs that might stop me dead in my tracks from doing anything I wanted to do on my phone. However, now, I mostly just dive headlong into the update (and break all hell loose if anything untoward takes place, which I must add thankfully has yet to happen).
I’m running iOS 6.1.2 which at the time of writing is the latest iOS release, with iOS 6.1.3 doing the rounds in beta. However, of late, I have been noticing, rather infrequently, that my iPhone 4S stops waking up from sleep. The first time that happened I immediately thought the phone had frozen up and required a cold reboot (this hard and cold reboot terminologies continue to confound me to this day). Pressing the home button or the sleep button, or holding down either of them does nothing. The phone appears dead.
Luckily, right the first time it bumped its ugly head and gave me a scare, I accidentally managed to find a workaround to it. While pressing the two hardware buttons on the phone in the desperate hopes of waking up or rebooting the phone, I found out that simply pressing the Home and Sleep buttons together, as when taking a picture of the screen, brings the phone back from sleep, with that familiar click sound that comes from having taken a snapshot. And in fact, it does take a snapshot. Only, it also triggers the phone to wake from the sleep from which it appears to not wake up any other way.
I don’t know whether this bug has to do with iOS 6.1.2, iPhone 4S, iOS 6.1.2 on iPhone 4S, or something else entirely on my phone (say any app or a corrupt setting, though I have tried rebooting the phone and still found the problem to occur). It doesn’t occur all the time, or even from time to time: it’s quite infrequent. In fact, I’ve only had it bother me twice or thrice. But it did happen. And pressing Sleep and Home together helped pull me out.
I hope it helps you too if the Apple gods forbid you run into this issue on your iOS device.