Some of us have been there before: everything seems to be going fine when, suddenly, your iPhone switches off. It randomly switches off. And it won't wake up either. In most cases, this is a battery charge issue. (Your iPhone won't switch on even if there's 5% battery remaining). But it could also be due to other problems.
We've tried to list them out here. Since this is a vague and an ambiguous problem, troubleshooting an iPhone not turning on after randomly switching off can take a lot of trial and error. Be sure to hit us up if your iPhone goes kaput and you need to wake it up.
#1. Sleep/Wake+Home Button
- Press and hold the home button and the sleep/wake button simultaneously. Ideally, this should trigger the iPhone into displaying the Apple logo. If it worked, the next step is to press and hold the two buttons again till the screen goes blank. Then, press the home button to see if the iPhone boots.
- If the iPhone shows the Apple boot logo but stops here (stuck at the boot logo), you might have to connect it to the computer (and open iTunes to do a recovery fix).
#2. Connect to the wall charger & wait
- The first thing you'll need to try out is connecting the iPhone to a wall-charger. It might not necessarily be a battery issue but this is the first thing to try.
- After you connect, don't expect the iPhone to boot up instantly. You might have to wait for about 5-10 minutes. In some rare cases, it might take up to 20 minutes for the iPhone to boot.
- If the iPhone boots up after a while, check the battery icon. If it's in the red zone, we're just talking about a battery-issue. If not (if the battery is above 20%, green), some issue with the software might have caused the iPhone to shut down abruptly.
- If the iPhone does not fire up at all, try pressing the home+sleep/wake button while the iPhone is connected to the wall charger. There is no logic behind this except that the combination usually kicks iPhone into the recovery mode. If this worked, you should see a “connect to iTunes” screen which shows a lightning cable and the iTunes icon. When this happens, connect your iPhone to iTunes and proceed to do a recovery/restore. (yes, data is at the risk of being lost unless you've backed up before).
#3. Connect to PC/Mac and open iTunes
- Whether or not the wall-charger method worked, you can try connecting your iPhone to the computer and firing up iTunes.
- Wait for a few minutes after connecting to the PC/Mac. If you're lucky, iTunes will recognize the iPhone (and throw a dialog window saying so). If you're real lucky, the iPhone will show the Apple boot logo and boot up normally within seconds.
- In some cases, iTunes doesn't recognize the iPhone. Neither instantly, nor after a few minutes have passed. In these cases, you will have to press the home and sleep/wake button. That will (hopefully) put the iPhone into recovery/DFU which will trigger an alert from iTunes. Proceed to recover/restore the iPhone. Again, data might be compromised.
I can almost hear you complain. “Why is data being affected?” This is not true in all cases. Only where you might have to push the iPhone into recovery mode that it so happens that data will get erased during the recovery/restore. In most cases, the iPhone wakes up and heads straight to the homescreen with all data safe and intact.
#4. Check for physical damage (screen, sleep button, home button, liquid etc.)
A physical damage might also cause a random, abrupt switch-off.
- Check the power button: is it pressed or damaged in someway? If the power button is damaged, it could be causing a circuit issue within the iPhone that could switch it off randomly (and prevent it from switching on)
- Liquid damage: in case of your iPhone coming into direct contact with a liquid (most likely, water) the screen circuits might be affected. That might prevent the screen from turning on or displaying anything. Check for indications (a red label in the SIM tray for iPhone 5s/5/5c, in the dock connector for iPhone 4/4s) in the liquid contact indicator. If there's liquid-based damage, the warranty won't cover it but there's only one way to get the problem fixed: Apple service center.
If none of these apply (or you have tried all of these but the iPhone won't switch on), you might have to take your iPhone to Apple care/service center.