Keyword: iPhone 6P/6, 5C/5S/5, 4S/4, 3GS/3G, iPad Air 2/1, iPad Mini 2/1, iPod Touch, Stuck, Apple Logo, recovery mode, DFU mode, connect to itunes, dead, frozen, water damage, jailbreak, ios update, ios 8.1/7.1/6.1..., iPhone reset, factory settings, battery replacement, iPhone reboot, stuck on the circle loading screen

When your iPhone does not respond or does not turn on or just froze:

Solution I: In any cases your need to try to re-start your iPhone:

Re-start an iPhone is the same as turning an iPhone on and off. Use this technique to try to solve basic problems like poor cellular or Wi-Fi connectivity, app crashes, or other day-to-day issues. Here's how:
1. Hold down the sleep/wake button (on some models it's on the top of the phone, on others, it's on the side) until the power-off slider appears on the screen

2. Let go of the sleep/wake button
3. Move the power-off slider from left to right. This causes the iPhone to shut down
4. When the phone is shut off, hold down the sleep/wake button again until the Apple logo appears on the screen. When it does, the phone is starting up again. Stop pressing the button and wait for the iPhone to finish starting.

Solution II: Try to re-set your iPhone if "re-starting iPhone does not work" or the iPhone won’t power down:

The basic restart solves a lot of problems, but it doesn't solve them all. In some cases—such as when the phone is completely frozen and won't respond—you need a more powerful option called a hard reset.
A hard reset not only restarts the phone, but also refreshes the memory that apps run in (don't worry; this doesn't delete your data) and otherwise help the iPhone start from scratch.
In most cases you won't need a hard reset, but when you do, follow these steps:
1. Hold the sleep/wake button at the top right of the device and the Home button at the bottom center of the face at the same time.


2. Hold them both until you see the screen go black. In some cases, you may need to keep holding them even after the red power-off slider appears. If it appears, just keep holding it.
3. Wait until the silver Apple logo appears.
4. When this happens, you can let go - the iPhone is rebooting.

Solution III: Retore to Factory Settings:

If you want to wipe all the data from your iPhone and start from scratch (this can solve some tough bugs and is also good if you're going to sell your iPhone), try restoring it to factory settings.

When you factory reset an iPhone, you're returning the phone to its good-as-new status, the state it was in when it left the factory. There will be no music, apps, or other data on it besides the iOS and its built-in apps and it will have all the original settings. In other words, a factory reset means you're completely erasing the phone and starting over from scratch.

Obviously it's a drastic step, and not something you do casually. But sometimes it's what you need. Circumstances in which you'd want to factory reset your iPhone include when you're selling it, when you're sending your iPhone in for hardware repairs, or when there's a problem with the iPhone so severe that starting from scratch is your only option (problems with jailbreaks gone bad are often fixed by this way).

Solution IV: Recovery Mode: If your iPhone is stuck in a reboot loop, or won't boot past the Apple logo, try recovery mode.:

When an iOS device encounters software- or app-related trouble, it can usually be resolved by just restarting. In some circumstances, though, the problems are more extensive and require putting the device into recovery mode and restoring it.
While this article mostly refers to the iPhone, the tips in it apply to all iOS devices: iPhone, iPod touch, and iPad.
When to Use It
You'll want to use iPhone recovery mode when:
You've installed an iOS update and your device gets stuck in a continuous restart loop. This can happen when something goes wrong with the update, or when you have extremely low battery life when installing the update
You attempted to update the OS or restore the device from backup, the process didn't complete, and now iTunes doesn't register the device when you connect it to your computer

How to Know When to Restore Your iPhone
The silver Apple logo has been onscreen, with no change, for many minutes.
It's worth knowing that restoring your iPhone via recovery mode will delete all data on the device (if you go through the entire process; exiting recovery mode before completing a restore leaves your data intact), so it's best to sync the device to backup your data, if you can, before following these instructions.
How to Enter iPhone Recovery Mode
1. Connect the USB cable used to sync your device to your computer, but do not connect it to your iPhone.
2. Turn your iPhone off by holding down the sleep/hold button in the top right corner until the slider appears at the top. Slide it. If your phone won't respond to that, hold the sleep/wake button and the home button together until the screen goes dark.
3. When the phone is off, hold down the home button and connect the USB cable (which should still be attached to your computer) to the dock connector. The iPhone will turn on and display the Apple logo. Keep holding the home button until the iTunes logo/USB cable appear on the screen. You can let it go then. The phone is now in recovery mode.
4. If the red empty battery icon appears onscreen, let the phone charge for a few minutes and then restart this process.
5. When the phone is in recovery mode, a window will pop up in iTunes saying that the phone is in recovery mode and needs to be restored.

Restore iPhone
Once your iPhone is in recovery mode, you'll need to restore it. You can either restore it to its factory state or from a recent backup of your data.
Remember, when you restore your device, it will delete all the data on it and replace it either with its factory default state or the backup you choose. Get Out of iPhone Recovery Mode
You can exit recovery mode before deleting your data and restoring your phone. To do so, unplug the device from the USB cable. Then hold down the sleep/wake button until it turns off. Let go of the button and then hold it down again until the Apple logo reappears. Let it go and the device will boot up. This only works, of course, if your device was working properly previously.

Tips 1: Stuck on the Apple Logo screen Solution:
Is your iPhone refusing to boot up all the way? Is it stuck at the Apple logo or continually turning on and off but not ever getting to the home screen. If you're seeing this behavior, you may think your iPhone is ruined. But that's not necessarily the case. Try the tips below to get your iPhone out of a start up loop.
After jailbreaking, updating the iOS, or restoring from an iPhone backup, a problem can sometimes occur in which the iPhone won't boot properly. In this situation, the iPhone can get stuck at the Apple logo, or sometimes in an endless loop of rebooting—both of which render the device temporarily unusable.
In most cases, you can solve these problems by putting the phone into recovery mode and restoring it from backup.

Tips 2: What is recovery mode and DFU mode?
iPhone Recover Mode is used when updating or restoring an iPhone that is otherwise unresponsive. It is also used by some Jailbreaking techniques but you can also use it to recover a seemingly dead iPhone.

DFU or Device Firmware Upgrade mode allows all devices to be restored from any state.
Entering DFU Mode on iPhone, iPad or iPod touch
1. Plug your device into your computer with a USB cable.
2. Turn off the device.
3. Hold the Power button for 3 seconds.
4. Hold the Home and Power buttons for 10 seconds.
5. Release the Power button but keep holding the Home button.
6. After about 15 seconds you will be alerted by iTunes saying that it has detected a device in Recovery Mode.
Make sure the device screen is blank and no logos are present
Exiting DFU Mode on iPhone, iPad or iPod touch
Hold the Home and Power buttons until the Apple Logo appears.

Tips 3: How to keep your iPhone data witout losing them for your iPhone restore from the recovery mode?
The perfect solution to bring your iPhone out of the iPhone Recover Mode above mentioned means you will lose all the data on your device: it will be restored to the most recent backup on your computer.
There's a utility called TinyUmbrella (for Mac and Windows) which claims to get your iDevice out of recovery mode without erasing any data, so you shouldn't lose any photos, videos, contacts and so on. Other applications are availble, such as RecBoot for Mac OS.

But we can't vouch for it as we haven't tried it or cannot guarantee the actual effects. However, we tested some try-and-buy iphone data recovery software and find Fonelab does well to recover or restore iPhone Contacts, Text Messages/iMessages, Call history, Calendar, Notes, Reminder, Safari bookmark, WhatsApp, App Document as well as data from Camera Roll, Photo Library, Photo Stream, Message attachments, Voice memos, WhatsApp Attachments, Voicemail, App Photos, App Videos, App Audio , etc.

When you run these utilities, they offer an option to enter or exit recovery mode - it's a simple case of clicking the button with your iPhone or iPad already connected to your PC via a USB used when updating or restoring an iPhone that is otherwise unresponsive. It is also used by some Jailbreaking techniques but you can also use it to recover a seemingly dead iPhone.