The basic troubleshooting steps, referred to as the Three R's, are "Restart, Reset, Restore." This article will help explain each of these steps.
You may want to perform these steps if your device is frozen, if an app is not performing the expected function, or if there is any other issue you think can be solved by software troubleshooting.
Be sure to do these steps in order. For example, if a simple restart solves your problem, you would not want to take such a drastic measure as restoring your device and erasing the data. Moving on to the first step, the first thing you want to try is a restart.
Close the App
If a particular app is causing an issue, try closing the app first, as described here: Closing Apps on iOS
Doing a Restart
Hold the power button (the button on top) down until the red "Slide to Power Off" slider appears. Slide your finger across the screen.
After the device is powered off, hold down the power button for a few seconds until the Apple boot logo appears; this means the device is turning back on.
If this fails to fix the problem, the next step is a reset.
Doing a Force Restart
Hold the home and power buttons at the same time until the Apple boot logo appears. No data will be lost. Force Restart is actually just a force reboot of the device, but packs more of a punch than a simple restart. It used to be called a "reset," but this caused some users to think that it would cause data loss.
If all else fails, it is time to do a restore.
Doing a Restore
Two ways to do a restore: In iTunes or directly from the device (iOS 5 or later).
The device should be plugged into a computer with iTunes loaded on it. Open the iTunes application, and locate the DEVICES menu on the left, then select your device. There should be a button to restore. The device will now be restored to factory settings.
On the Device:
Click on the Settings icon, then click on General. Scroll to the bottom and click on Reset, and finally "Erase all Content and Settings."
If you have iOS 5, the device should power back on and display the setup screens you saw when you first got the device. The below article will walk you through the setup screens.
Corresponding Apple Club Article (will take you to the Apple Club's Advice and Articles page)
Choosing the Erase All Content and Settings option will not reload the iOS like an iTunes restore would, however if the cause of your issue is some corrupted data, then this will take care of it. Try running your device for a little while with nothing installed on it, and test the various built-in apps. If the problem persists, you can try an iTunes restore. If it's solved, try loading your data back manually, little by little, to help determine what the problem is.
Note that you can still choose to restore from the device without iOS 5, but you will be prompted to set up the device in iTunes when the restore is complete on iOS 4.3.5 or earlier.
There are two options when doing a restore: "Restore from Backup" and "Set Up as New Device." First, you want to try restoring from a backup, as this method will not cause a loss of data, as long as you have a recent backup. This will show up either in iTunes or on the device (iOS 5). After selecting Restore from Backup, you will be able to choose from a list of devices and backups. These backups are accessed based on any backups performed on your computer (if restoring using iTunes), or by signing in with your Apple ID (if restoring from an iCloud backup on your device).
If the problems still is not fixed, you will have to repeat the process, except "Set Up as New Device." This will set up the device as if it were fresh out of the box. Purchased media will be able to be re-downloaded without you being double charged as long as you sign in with the same Apple ID. If you are having difficulty restoring or have forgotten the passcode on your device, see this Apple article for help.
Corresponding Apple Article: (will take you to Apple's website)
Force Quit Apps
If an application freezes or is not responding, you can force the app to close. To do so, hold the power button until the red slider "Slide to Power
Off" appears. DO NOT slide the slider. Instead, hold the home button for 5 or 6 seconds, and you should be returned to the home screen.
Doing a reset or restore may fix most issues, but for network-related issues, there are a couple more things to try.
1) Try opening Settings. The option at the very top is Airplane Mode. Turn this on, wait a few seconds, and turn it back off.
2) Tap on the Settings icon, and select the General menu. Scroll to the bottom and tap on Reset, and finally "Reset Network Settings." The device will take a minute or so to reboot, and then hopefully the network issues are resolved.
Article ID: AT4812
By Jane on 1/24/14 • Reply
The screen was hung up on the call log screen after being on a call and the call dropped. I could receive calls, but could not change the screen. the power button would not power off the phone
doing a Reset fixed the problem
By suz on 12/13/14 • Replythanks, your article solved my problem and lots of time and headaches---which I had begun to have. Very well presented with links when needed.