Common iPhone 6 and 6 Plus problems, and how to fix them

Problem: iPhone shuts down on its own, or awful battery life

In 2016, Apple started a free battery-replacement program for iPhone 6S units that would shut down unexpectedly. People had complained that their iPhones would just turn off if they dipped below 30 percent battery life.

Apple hasn’t announced any such recall for the iPhone 6, but an increasing number of people have been complaining about their iPhone 6 smartphones shutting down on their own after dipping below 40 percent. Others have complained about very bad battery life.

Potential solutions:

• If you’re experiencing bad battery life, we recommend that you follow our iPhone battery tips to make your iPhone battery last longer.
• If you’re one of the unlucky owners of an iPhone 6 who is experiencing shutdowns, we are sorry to say that there is no replacement program for the iPhone 6, as there is for the iPhone 6S. We recommend that you visit your local Apple retail store or contact Apple directly on the phone. You may have a hardware issue.
• Battery performance will deteriorate over time, so it may be worth looking into getting a battery replacement. Apple offers a replacement service for $79.

Issue: iPhone is slow or lagging

There have been a few reports of iPhone 6 and 6 Plus handsets becoming sluggish, particularly after receiving an update. If you find that there are delays when tapping or swiping, or perhaps apps take a few seconds longer to open than they once did, then there are a few things you can try.

Potential solutions:

• Begin by restarting your iPhone. Press and hold the Sleep/Wake and Home buttons simultaneously, until you see the Apple logo.
• If that doesn’t help, then try performing a factory reset and restoring your device from a backup.

Glitch: GPS not working

Quite a few people have run into an issue with the GPS function in the iPhone 6. They might be using Apple Maps, Google Maps, or any other app that employs the GPS, but find that it’s inaccurate or very slow to update. That said, it may still work fine when they’re connected to Wi-Fi.

Potential solutions:

• Check in Settings > Privacy > Location Services and make sure Location Services is toggled on at the top. Then, check the rest of the settings and ensure nothing important has been toggled off.
• If you have a case on your iPhone, then remove it and test the GPS again.
• You may want to try resetting your network settings via Settings > General > Reset > Reset Network Settings. Keep in mind, however, that you will have to re-enter some passwords and set up your network connections again after this.
• There’s a chance that your hardware is failing, in which case replacing the antenna or the cable connecting it to the logic board will resolve the issue. This has worked for some people, but not everyone.
• You could try going into an Apple Store, but the employees may suggest that you buy a new iPhone.

Problem: iPhone screen freezes

Some iPhone 6 and 6 Plus users have found that their device’s display becomes unresponsive when using apps. The problem has been reported on the Apple forums many times, and we’ve seen the same issue reported back in iOS 9.3.1. The issue has been known to occur multiple times in a single day.

Workarounds:

• Use the lock button to turn the screen off and on again.
• Hold down the Sleep/Wake and Home buttons until you see the Apple logo appear to reset your iPhone.
• Factory reset and restore your device as a new phone, or restore it from a backup.

Potential solutions:

• If none of the aforementioned workarounds fixes the problem, consider contacting Apple or going to an Apple Store. The problem may be with the hardware, not the software.

Problem: Can’t send or receive iMessages and texts

Some users are struggling with an issue where a contact or multiple contacts are unable to receive iMessages and texts from an iPhone 6 or iPhone 6 Plus user, though they can still receive texts from other contacts. Some people are unable to send text messages, and for others, iMessages don’t appear to go through properly. This problem has cropped up in various versions of iOS, including iOS 10.

Potential solutions:

• Turn iMessage off and back on, or turn iMessage off to see if texts can be sent and received.
• Make sure the contact is not on your block list. To do so, go to Settings > Phone > Call Blocking & Identification, and confirm that the user is not on any block list.
• If you have an old iPhone or another iOS device that you sometimes use for iMessages, try toggling iMessages off there and sign out of your Apple account. You can sign out by going to Settings > Messages > Send & Receive and tapping on your Apple ID, then choose Sign Out.
• Delete your current conversation with the problem contact(s) and start a new one.
• Delete and re-enter said contact(s).
• Simultaneously hold the Sleep/Wake and Home buttons to reset your device.
• Try going to Settings > General > Reset > Reset Network Settings. You will have to re-enter some passwords and set network connections up again after this.
• You could try a factory reset of your iPhone.
• Contact Apple Support, or take your device to an Apple Store to get it checked out.

Problem: Unable to update to iOS 11

Every time a new iOS version rolls out, some users have trouble with the update, as discussed on this thread in the Apple forums.

Potential solutions:

• If you’re doing an OTA (Over The Air) update through WiFi, you will need around 1.5GB of free storage on your device. If you’re having issues with the OTA update, check out Apple’s over-the-air help page for more information.
• Make sure that Wi-Fi is on and go to Settings > General > Software Update on your iPhone.
• If you can’t update directly on your iPhone, then try plugging into your PC or laptop. Make sure you’re using the latest version of iTunes, which is 12.7 at the time of writing.
• If it doesn’t work, then hold down the Sleep/Wake and Home buttons together on your iPhone 6 while it’s still connected to your computer. Wait until you see the recovery screen — you should see the Apple logo and then the iTunes icon with the cable. Choose the Update option on your computer when it appears.
• If met with an error code, check Apple’s detailed support page on what the different error codes mean and what to do.
• Contact Apple Support, or take your device to an Apple Store.

Problems with red screen flashing, hearing calls, and more

Problem: Red screen

A number of iPhone 6 and 6 Plus owners have reported a problem in which their iPhone’s display goes — or flashes — red before showing the Apple logo. Sometimes the problem goes away on its own and returns later, and sometimes it sticks around and the display refuses to turn off.

Workaround:

• Try simultaneously holding down the Sleep/Wake button and the Home button for 10 seconds, or until you see the Apple logo. In some cases, the iPhone will restart normally, but the problem might come back.

Potential solutions:

• There’s a possibility that this is a software issue, perhaps pertaining to a corrupted backup. You can try the restore process to fix it. Hold down the Sleep/Wake button to turn your iPhone 6 off. Make sure that your computer is running the latest version of iTunes and plug your iPhone in with a USB cable. Now, simultaneously hold down the Sleep/Wake and Home buttons for a few seconds, and when the device comes on, let go of the Sleep/Wake button while continuing to hold down the Home button. You should get the Connect to iTunes screen and you can let go of the Home button. Then, follow the restore procedure through iTunes.
• It’s also possible that this is a hardware failure of some kind, and in that case, you’re going to have to contact Apple or visit an Apple Store and arrange a replacement. It might be a good idea to record the red screen using another device, just in case your iPhone 6 works normally when you take it in for an assessment.

Glitch: Enlarged image or icons filling screen

It’s fairly common to hear reports about enlarged images or icons on the iPhone screen making it difficult for people to see properly or navigate. There’s a good chance that this has been caused by the accessibility feature, Zoom, and it’s easy to fix.

Solution:

• Hold three fingers together and double tap the screen and you should see things return to normal.
• To make sure that it doesn’t happen again go to Settings > General > Accessibility and turn Zoom off.

Issue: Can’t hear during calls

Quite a few people have run into an annoying issue where they can’t hear the other caller during a phone call. They can make and receive calls as normal, but they can’t hear the person on the line, or they sound muffled even when the volume is turned up.

Potential solutions:

• Try using the Volume up button and make sure that the ringer volume appears on screen when you press it and not headphones.
• Make sure that nothing is covering the speaker. A screen protector, a case, or even dust can have a big impact. Use a brush or blow gently into the speaker to make sure it’s free of any blockages.
• Make sure that you don’t have anything plugged into the headphone port. It can be worth plugging in headphones and taking them out again just to test if that helps.
• Try turning Bluetooth off via Settings to make sure that you aren’t connected to a headset or car system. If you regularly use a Bluetooth device try connecting to it and then disconnecting to see if it makes a difference.
• You could try going into Settings > General > Accessibility and make sure that Phone Noise Cancelation is turned off, some people have found that this helped.
• Try toggling speakerphone on during a call and see if the issue persists.
• After you’ve tried the solutions above, hold down Sleep/Wake and Home together for 10 seconds until you see the Apple logo to reset the iPhone 6.
• If you’re still having the problem after trying all of these potential solutions then it’s time to talk to Apple and/or your carrier.

Problem: iPhone 6 won’t charge

We’ve heard a few iPhone 6 owners complaining that they are unable to charge their device up. They plug it in as normal and nothing happens or it will only charge so far.

Potential solutions:

• Make sure that you are using the cable and wall charger that came with your iPhone 6 or iPhone 6 Plus. If the charger or cable you’re trying to use isn’t Apple certified, then that could be your problem right there.
• Try using a different wall socket, a different cable, and a different charger.
• Take a look at the connector on your cable and the port on your iPhone. Make sure that they’re clean and free of dust. You can blow into the port to clean it out or use a brush with soft bristles.
• There are reports that if you keep your Lightning cable in a humid or wet environment the connector can get corroded. If it’s wet then you should never plug it in because you could also damage the port on the iPhone. If it looks corroded or there’s something on the connectors that you can’t remove with a microfiber cloth, then it’s worth taking the cable into an Apple Store to show them, they may just give you a replacement.
• Try resetting your device while it’s plugged into the charger by holding down the Sleep/Wake and Home buttons for 10 seconds or so until the Apple logo appears.
• There’s a chance that your battery is on its last legs. Take your iPhone into an Apple Store and ask them to take a look.

Glitch: No SIM card error

A few people have run into a glitch where the iPhone 6 keeps complaining about the SIM card. It might say “Invalid SIM” or “No SIM card installed.” There are a few things worth trying.

Potential solutions:

• Try toggling Airplane mode on and off again.
• Restart your iPhone by turning it off and on again.
• If you recently inserted the SIM card and started getting the error, then there’s a chance it’s damaged or dirty. Try popping it out and taking a look. You can use a pencil eraser to clean the gold contacts and then blow away the debris before putting it back on your iPhone.
• If you’ve dropped your iPhone 6, or it was damaged somehow, then there’s a chance the SIM tray is loose. Some people have had success by putting a small, thin piece of packing tape on the back of the SIM card and then re-inserting it.
• Make sure that your software is fully up to date via Settings > General > About.
• Try the SIM card on another device if you have a compatible device, or try a different SIM card in your iPhone 6.
• If the problem persists then contact your carrier or Apple.

Problems with bent iPhones, cracked screens, and more

Problem: Bent iPhone 6 Plus

The bent iPhone 6 Plus problem has stirred up a storm of coverage online, but Apple claims it’s not common and that only nine people have actually contacted the company to complain about a bent iPhone 6 Plus. We suspect there will be more in the coming weeks. The thin design and larger body obviously make it a lot more likely to bend than last year’s model, but if you look after it and don’t try to bend it, then it’s not likely to happen to you. Whether you believe it’s a big issue or not, there’s only one thing to do if it happens to you.

Solution:

• If the iPhone is only slightly bent and there are no other issues, a good case can help with the rigidity of the iPhone 6. Check out our picks for the best cases for the iPhone 6 and the iPhone 6 Plus.
• Again, if your iPhone 6 is only slightly bent, and there are no other issues, you can stop it from getting worse by being more careful about how you carry your smartphone. If you carry your smartphone inside very tight jeans or in a back pocket that may be the reason it is bent.
• Contact Apple or take it into an Apple Store and they’ll inspect it and decide whether to offer you a free replacement.

Issue: Cracked screen

A lot of people report that the iPhone 6 and the iPhone 6 Plus are easy to damage when dropped. There’s always a risk when you drop your smartphone that the screen is going to crack. That’s why it’s a good idea to invest in a protective case. If you’ve got a broken iPhone 6 screen, then here’s what to do:

Potential solutions:

• Run through our guide on how to repair your smartphone for DIY advice, repair shops, and services.
• Go directly to Apple where an iPhone 6 screen repair will cost you $109, or $129 for the iPhone 6 Plus.

Bug: Touch ID not working

We’ve seen thread after thread on the Apple forums about iPhone 6 owners being unable to use Touch ID. It sometimes stops working after a software update and occasionally attempting to remove and re-add fingerprints can lead to a situation in which Touch ID setup fails over and over.

Potential solutions:

• Hold the Sleep/Wake and Home buttons to trigger a forced restart (the Apple logo will appear).
• Clean the area around the iPhone’s Home button with a soft, microfiber cloth.
• Go to Settings > Touch ID & Passcode, delete your fingerprints, and tap Turn Passcode Off. Turn your iPhone off and back on again, then go back to Settings > Touch ID & Passcode and set it up afresh.
• Create a backup using iTunes and restore your device using that backup. If the problem persists, try a factory reset, but don’t restore the backup. Set it up and test to see if Touch ID works correctly.
• If you’re still having problems it’s time to contact Apple.

Glitch: Bluetooth not working

A lot of new iPhone 6 or iPhone 6 Plus owners are having trouble connecting with Bluetooth devices, particularly systems in cars. Some people can’t get the in-car system to work, while others are having trouble establishing any connection at all. It doesn’t seem limited to any specific manufacturer. We’ve seen reports about a wide range of car models, including Toyota, Mercedes-Benz, Nissan, Honda, Acura, BMW, Jeep, and more. There are reports that the connection works fine with older models of iPhone.

Potential solutions:

• You should delete all pairings from your car or another Bluetooth device. Now go to Settings > General > Reset > Reset Network Settings on your iPhone. Now hold down the Sleep/Wake and Home buttons together until you see the Apple logo on your iPhone. Make sure your car or device is discoverable, and try setting up the connection from scratch.
• Some people reported success after a factory reset. Check out how to factory reset an iPhone.

Issue: Unresponsive touchscreen

A few people have been complaining that the touchscreen on their new iPhone 6 is randomly unresponsive. This seems to manifest as a keyboard problem where it’s sluggish and certain keys don’t seem to work in portrait mode, but some reports talk about the whole side of the screen being unresponsive. In some cases, it’s accompanied by a gray flickering bar at the top of the screen.

Potential solutions:

• The first thing to try is restarting your iPhone 6 by holding down the Sleep/Wake button and the Home button together until you see the Apple logo. The problem might return.
• Some owners had success after trying Settings > General > Reset > Reset All Settings (you’ll need to re-enter passwords, change the wallpaper, set up Touch ID again, but it won’t delete your data).
• Others report success after a factory reset, but you’ll lose everything if you do this, so backup first. You may need to set up your iPhone 6 as a new phone rather than restoring, a few people found that restoring from an iTunes or iCloud backup brought the problem back again.
• There’s also a possibility that this is being caused by a hardware fault and there’s a problem with some of the connections inside the iPhone. If that’s the case, you’ll need to seek a repair. It might be worth taking your iPhone into an Apple Store and asking them to take a look.

Problems with the camera, random crashing, and more

Problem: Camera not working

There seems to be more than one problem with the iPhone 6 camera. Tom’s Guide ran a piece about purple tinges and possible chromatic aberration, though that appears to be software related as it happens on the iPhone 5S with iOS 8, as well. We’ve seen a few reports of people starting up the camera app on the iPhone 6 and 6 Plus only to find a black screen. We’ve also seen reports of photographs being rotated to the wrong orientation.

Workaround:

• A reset could temporarily get rid of the problem. Hold down the Sleep/Wake button and the Home button together until you see the Apple logo.

Potential solutions:

• Try going to Settings > General > Reset > Reset All Settings and see if that makes a difference. You will need to set up some bits and pieces again after, but it won’t delete any files or photos.
• Some owners found it was caused by an old backup. If you are restoring from a backup you made with an older iPhone, that could be the problem. Try setting the iPhone 6 up as new, factory reset it, and then put everything on it manually, and you might find that the problem is gone.
• If it persists, then you may have a hardware fault and you should contact Apple or head into an Apple Store to get it looked at. They should replace it for free if there’s a problem.

Bug: Random crashing, and boot loop

A few iPhone 6 and 6 Plus owners have run into an issue where their iPhone repeatedly crashes or shuts down without any apparent reason. For some people, the iPhone 6 is then getting stuck in a boot loop where it repeatedly turns itself off and on again. It might happen when launching an app and it might display a blue or red screen.

Potential solutions:

• It could be a software problem. Check in Settings > General > Software Update and tap Download and Install when you see a new update. Apple says iOS 10.2.1 resolves the issue.
• If you keep encountering this issue with a specific app, then try deleting it and reinstalling it.
• There’s a chance that this is down to old settings or specific apps. You could try a factory reset and then set the iPhone up as new and reinstall apps selectively, but that’s quite a radical step and there’s no guarantee it will work.
• If this is genuinely a hardware problem, then you’re going to need to get a replacement handset from Apple. Take it into an Apple Store if possible and they’ll probably try a restore. If the problem persists they should offer you a replacement.

Problem: Dye coloring the plastic strips

The iPhone 6 and iPhone 6 Plus have plastic strips in the svelte body to ensure that the antennas can hold a signal. Unfortunately, they are a necessary evil, though plenty of people find them ugly. Some owners have found that slipping the phone into a tight jeans pocket results in some of the dye sticking to the white plastic on the gold model and discoloring it. This has happened with many other smartphones in the past (like the white HTC One X), so it’s not a new or exclusive problem.

Workaround:

• Put a case on your iPhone, it’s a fragile device that’s going to break easily if you drop it, so it’s worth considering a case anyway and it should prevent this problem or hide it.
• Wear white jeans (just kidding … although it would work).

Potential solutions:

• A pencil eraser proved effective for some people.
• Start with a damp cloth and work your way up the cleaning products until you manage to remove the marks. Just be careful not to get any cleaning fluid on the screen or the rest of the iPhone body.

Issue: Headphones crackling or odd behavior

Quite a few people have had trouble getting their headphones to work perfectly with their new iPhone 6. It seems that there are a couple of different issues here. One relates to the headphones poking out the top and crackling noises. The other concerns Siri auto-launching and other strange behavior like music stopping or volume controls on the headset not working.

Potential solutions:

• Start by blowing into the headphone port and clean the headphone jack to make sure there’s no dust or dirt causing this problem.
• If you’re using the headphones that came with the iPhone 6 or another official Apple set and you’re getting crackling, then check to see that they’re properly plugged all the way in. There shouldn’t be any metal visible at the top. It may feel tight, but it should snap all the way in.
• People using third-party headphones, especially if they have a microphone, seem to be inadvertently triggering Siri or experiencing frequent cut-outs. This could be because the metal at the top of the plug is touching the iPhone body. Some people report success by using scotch tape, plastic, or even dental floss wrapped around the top of the headphone jack. Just make sure you don’t use something that could get stuck in the port.
• If the problem persists, there’s a chance it’s a hardware fault. Go to Apple and have them take a look. If they can’t resolve the issue, then you should be able to get a replacement handset.

Issue: Overheating iPhone

Smartphones get warm to the touch when charging, or if you’re playing a graphically intensive game, but they should never get burning hot. There are some reports the iPhone 6 and 6 Plus can get especially hot, and not under the conditions mentioned above. Areas of concern include the rear panel, particularly near the volume controls.

Workarounds:

• A restart should help it cool down, but it may overheat again in future. Hold down the Sleep/Wake button and the Home button together until you see the Apple logo.
• If you use a case try removing it.

Potential solutions:

• A problem app or something in your backup file could be causing your issue. Try a factory reset and don’t restore a backup, set it up as new instead and test to see if the overheating is gone. Reinstall apps one by one and watch out for the problem returning.
• If your iPhone is so hot you risk burning yourself, then you need to take it back to Apple. Make an appointment with the Genius Bar at your local Apple Store.

Problems with booting, Wi-Fi, iTunes, and email

Problem: iPhone won’t turn on

You might find that your iPhone 6 sometimes refuses to turn on when you press the Sleep/Wake button. Perhaps it unexpectedly turned off and now seems to be unresponsive, or you’ve just reached for it only to find that it won’t wake up. Here’s what to do:

Potential solutions:

• Start by holding down the Sleep/Wake and Home buttons together. Keep holding them down, for up to 30 seconds. It might feel like a long time, but keep holding them. The Apple logo should eventually appear. Check our guide on how to reset an iPhone.
• There could be a problem with the Sleep/Wake button itself, but you should be able to feel or see the fault. You’ll obviously need a repair it if it seems to be damaged.
• If that doesn’t work, then the battery is probably dead. Plug your iPhone into the charger and leave it for half an hour, before trying to turn it on again.
• If it still doesn’t respond, then try plugging your iPhone into your computer and launching iTunes. You may find it recognizes your iPhone and indicates that it’s in recovery mode. If so, you should try restoring it.
• If nothing works, then it’s time to visit an Apple Store or contact Apple regarding a repair.

Issue: Won’t connect to Wi-Fi or drops

A lot of people have had trouble with their Wi-Fi connections on the iPhone 6 or 6 Plus. If you find that you can’t connect to a Wi-Fi network, or that your connection frequently drops or slows down, then there are lots of things you can try.

Workarounds:

• Toggle Wi-Fi/Airplane mode: You might find that it temporarily comes back if you toggle Wi-Fi off and then on again. Alternatively, you could switch Airplane mode on and then turn it off again. Swipe up from the bottom to open the Control Center and toggle these settings.
• Reboot: Some people report temporary success by switching the device off and on again. Press and hold the Sleep/Wake button and the Home button for 10 seconds or so, until you see the Apple logo. Your Wi-Fi may work again for a while.

Potential solutions:

• Set up the connection again: Go to Settings > Wi-Fi and tap on the problem network, then select Forget this Network and tap Forget. If you go back to the Wi-Fi page, you should now be able to choose your network and set up a fresh connection.
• Reset Network Settings: Try going to Settings > General > Reset and tap Reset Network Settings. This has worked for a few people, but the problem might return.
• Turn off Wi-Fi Networking: Try going to Settings > Privacy > Location Services and under System Services you need to toggle off Wi-Fi Networking.
• Turn off Wi-Fi Assist: It’s designed to switch you to your mobile data network when Wi-Fi is patchy, but it could be causing your problems. Go to Settings > Cellular and scroll down to toggle Wi-Fi Assist.
• Toggle 2.4/5GHz: If you have a two-channel router, then try changing from 5GHz to 2.4GHz. Generally speaking, 5GHz is faster, but with a shorter range. Some people report a better connection on 2.4GHz and a few find an improvement by switching the other way.
• Change router channel: You could also try changing the channel on your router. You’ll need to put your router’s IP into your browser and login to change settings. Refer to your ISP for instructions.
• Switch DNS to Google: Some people report success after switching DNS to use Google servers. You can do this via Settings > Wi-Fi then tap the ”i” icon next to your router, scroll down to DNS and tap the numbers and enter “8.8.8.8”. You might have to restart your device for this to take effect.
• Turn off MAC Filtering on your router: It’s possible to add your iOS 9 device’s MAC address, but due to Apple’s MAC randomization there’s a good chance it’s going to change and refuse to connect the next time you try. The simplest solution is just to turn MAC filtering off altogether.
• Update your router firmware: You may need to check with your ISP or the router manufacturer.
• Factory Reset: It’s a drastic step with no guarantee of success, but you could try a factory reset. Here’s how to factory reset an iPhone.

Problem: iTunes restore error 53

A number of iPhone 6 and iPhone 6 Plus owners have encountered error 53 upon plugging the iPhone into a PC or Mac and attempting to restore through iTunes. It effectively leaves your iPhone in a reboot loop where it goes into recovery mode, prompting you to plug it in, and then iTunes says, “The iPhone could not be restored. An unknown error occurred (53).”

Apple admitted that the “Error 53” was their mistake and rereleased a patched version of iOS 9.2.1 that fixed this issue.

Solution:

• Update to the latest version of iOS via iTunes.

Glitch: Email not updating

Some iPhone owners have been having trouble with their email accounts not updating. New emails are not coming into the inbox, or perhaps they’re only coming in when the Mail app is opened.

Potential solutions:

• The first thing to do is go into Settings > Accounts & Passwords > Fetch New Data and take a look at your settings. If you want emails to come in as soon as they arrive, then make sure that Push is turned on. Otherwise, you can set the frequency that your iPhone checks for new email under Fetch.
• It’s worth checking that there’s nothing in your outbox. If there’s an email that’s failing to send and repeatedly trying, it could be causing your issues.
• Try switching Airplane mode on and off.
• Try deleting the email account via Settings > Accounts & Passwords, and then add it fresh.
• Go to Settings > General > Reset and try Reset Network Settings. You’ll have to set up your network connections again, but it can help with email issues.

Issue: No alert sound for incoming messages

If you find that you aren’t hearing any alert sound when a new message comes in, or perhaps you’re only getting alerts intermittently, then you aren’t alone. This is quite a commonly reported problem.

Potential solutions:

• Start by checking the obvious things: Turn the volume up, check that the mute switch isn’t on, and take a look under Settings > Do Not Disturb. Bear in mind that it’s possible to have Do Not Disturb turned on for specific contacts, in which case you’ll see a half moon icon next to the contact. Check the Details on any incoming message that you didn’t hear an alert for to make sure that’s not your problem.
• Go to Settings > Notifications and try toggling them on or off. Now, reboot the device and go back into turning them on again.
• You could also try Settings > General > Reset > Reset All Settings, but it means re-entering a lot of your settings afterward.

Update: We refreshed some of the solutions here and added a problem with the iPhone shutting down due to the battery.