Unknown error 21 when restoring iphone 5. iTunes errors when restoring, updating and syncing iPhone, iPod Touch and iPad (error codes, causes and solutions)

Apple products are renowned for their reliability, but errors often occur when using iTunes. Probably every user of an Apple gadget at least once, but faced this. Errors can occur due to a failure in the system or due to hardware failures. Error 21 iTunes refers to hardware.

You decided to update the device system and encountered error 21. How can it manifest itself? An error message appears and the working window of iTunes closes, after which it will be impossible to work in the program. After the error appeared, the computer turned off. You received a notification that says "iTunes Error 21". The operating system on a PC slows down when giving commands through the mouse or when typing on the keyboard. At times, the PC freezes for 3 - 4 seconds.

Such a failure can give alerts not only when working in iTunes itself, but also when using components associated with it. When the PC shuts down or when it is turned on, failure alerts may also appear 21. By detecting the occurrence of a failure in time, you can easily fix the problem.

Causes

Such a failure may occur due to incomplete installation of the components of the iTunes program or if these files are damaged. It can occur when the registry, which is responsible for the iTunes program, is damaged. This can happen due to the installation or removal of software working with the program.

System or program files have been corrupted by malware or viruses. Files necessary for the proper functioning of iTunes by another program have been deleted (intentionally or accidentally). The most common cause of the error is updating a jailbroken device.

How to fix Error 21

If you need to update your jailbroken device, you can use the DFU recovery using the "Redsn0w" program. Redsn0w allows you to restore any gadget from any state. In order to fix the failure, enter the device into DFU mode by simultaneously pressing and holding the "Home" and "Power" buttons for 10 seconds. After that, stop pressing "Power" by continuing to press "Home" until a message about the emergency recovery of the gadget appears in the iTunes window.

In this case, the display of the device should be without images. Wait for another message "The iDevice "iDevice" could not be restored..." and perform an IPSW restore. Other methods are aimed at eliminating the failure of gadgets that have not been jailbroken.

Update or install iTunes

Check if there are updates for the program and update it to the latest current version. If that doesn't help, try completely uninstalling and reinstalling it. Keep in mind that not all program components may be removed during uninstallation. Therefore, remove it using a special utility for complete removal. Only after that put iTunes again.

Turn off antivirus

Virus tracking software may perceive the actions of the program as malicious activity and, as a result, stop its work by means of blocking. In order to avoid such situations, you can turn off the antivirus program while working in iTunes or fix failures by disabling the antivirus program after they appear.

In the future, you can add iTunes to the list of exceptions. As a result, the antivirus program will not block its activity. You can do this in the settings. Provided that this function is already active, you need to disable network scanning.

USB cord

Failures can be caused by the use of non-original components or those that are damaged. Replace the non-original cable with an original one. If you are using the supplied cable, check its integrity. Do not neglect such a trifle, the use of good components can extend the life of your devices and get rid of such failures.

OS update

In order to update the Windows 10 system, press the two keys "Win" and "I". This combination will open the options window. Here you need to open the "update and security" section. A workspace will open in front of you, where there is a button "check for updates". Click it. If updates are found, install them.

If you are using an earlier version of Windows, open the Control Panel. Here, click "Windows Update" and check. If updates are found, install them.

DFU mode

This mode is for disaster recovery. It works at the hardware level, bypassing the operating system. Turn off the device completely and after a couple of minutes connect via USB cable to the PC. Open iTunes. To enter the gadget into DFU mode, you need to hold down the “Power” button for three seconds and then hold down the “Home” key as well. Hold them down for 10 seconds. After this time, stop pressing the "Power" button, but hold down the "Home" button until an alert appears in iTunes that the gadget is in emergency recovery mode. Click on the "recovery" button.

Garbage removal

When using a PC, over time, it accumulates a lot of unnecessary information. It can slow down the OS and cause error 21. This happens due to conflicts between files or when the hard drive is under heavy load. You can remove garbage with the Cleanmgr utility. It is built into the system, but has a number of disadvantages. For a more complete cleaning, it is better to use WinSweeper.

Click "Start" to start the process. Then enter "command" in the search string. Now hold down the Shift and CTRL keys and hit Enter. In the access dialog, click yes. A blinking cursor indicates an open black box. Type "cleanmgr ” and click Enter. In the dialog box, check the boxes where you want to clean. Pressing "ok" will start the cleaning process.

You can also restore registry entries. But you should not do it yourself if you are not an expert in this matter. With this question, it is better to contact a person qualified in this field, otherwise you can harm the PC and disable it. If the above methods did not work, go to the repair center to diagnose the device. May need hardware repair.

Hello everyone, we decided to look into error 21 when restoring iphone 4s. In this article, we will talk about the causes of the error and how to solve it.

The symptoms do not turn on, and when the cable is connected to the PC or to the network, it shows an apple and after 3 seconds the lanyard and iTunes icon, if the cable is disconnected, a black screen immediately appears.

Software solution for error 21

Trying to restore iphone in DFU Mode:

• Connect the device to the computer using a USB cable (original);

• Press the Power button (in the upper right corner) and hold it for 3 seconds;

• Without releasing the top Power button, press the HOME button (which is at the bottom center) for 10 seconds;

• Without releasing the HOME button, release the top Power button while CONTINUED TO PRESS the HOME button for 10 seconds;

• Launch iTunes. The program will detect the iPhone in recovery mode;

• Hold down the "Shift" key on your keyboard and click on "Restore" (Mac users should press "Alt+Restore");

• Open the ".ipsw" firmware file you downloaded earlier. iTunes will take over the rest of the work, wait for the process to finish.

If it doesn't work, clear the hosts file. Open the file C:\Windows\System32\drivers\etc\hosts (Windows) with notepad and put a # in front of all lines containing "gs.apple.com" and127.0.0.1 localhost or delete them. Save. Close. Flash again.

You can also take advantage the following programs to enter the device into the DFU Mode Pwnage Tool, sn0wbreeze or redsn0w.

Hardware solution for error 21

The repair method is as follows: Replacing the battery - Replacing the lower cable - soldering the battery connector (1) - jumpers (error 29 solved on youtube) - check the quartz (2) - replacing the power controller (4) - reballing the processor - musarka.

• First of all, you need to check the voltage on the battery, if it is less than 3.7 V, then we put it on charge using the "frog" or directly connect the wires to the battery;

• Second, check the cable and connectorpower must be undamaged;

• Third, remove the power cables, motherboard and put in place;

• Fourth power supply replacement ( it must be desirable from the original iPhone);

• Fifth, we check the controller supply if needed to be replaced.

Practical experience correcting error 21

The apple is on when it is turned on and a constant reboot, when the cable is connected - the aytyuns icon and that's it. When connected via cable to the computer, the program said that it was necessary to update or restore.

When flashing / restoring, there was ERROR 21. At this voltage on the battery was only 3.6 volts, the voltage on the board did not respond when measured, the voltage on the board was 0. After disassembling the device, oxide was found at the C135 capacitor next to the transmitter. the capacitor dropped out, put it on charge - charging went on the connector of the battery board, a voltage of 1.2 volts appeared when flashing / restoring, it gave error 6.

Switched to another computer with windows 7 64 bit disabled antivirus and firewall. I connected only the phone, without connecting third-party USB devices, the Internet was downloaded via Wi-Fi firmware separately and, when flashing, I held down the Shift button and selected the firmware file (preferably the path without Russian letters). Update did not work, restored. It didn't work the first time. So you have to try. At first, there was also error 6. As a result of long attempts, everything worked out. TA worked. Try it might help.

Similar components on iphone 5

Red - signal power amplifier GSM/GPRS/EDGE, Skyworks 77352-15;
Orange - switch module between antennas SWUA 147 228;
Yellow - UMTS signal power amplifier, also known as a duplexer, Triquint 666083-1229;
Green - Avago AFEM-7813 dual-band LTE duplexer;
Blue - CDMA signal power amplifier, Skyworks 77491-158;
Purple - LTE Signal Power Amplifier, Avago A5613 ACPM-5613;


Red - Qualcomm PM8018 RF power controller;
Orange - Apple 338S1131 power controller, manufactured by Dialog;
Yellow - 16 GB Hynix H2JTDG2MBR flash chip;
Green - multi-chip auxiliary memory module for LTE, Apple 338S1117, manufactured by Elpida;
Blue - three-axis gyroscope STMicroelectronics L3G4200D, as in the iPhone 4S and iPad 2;
Purple - Wi-Fi module Murata 339S0171.


Red - STMicroelectronics LIS331DLH triaxial accelerometer with low power consumption;
Orange - Texas Instruments 27C245I single-chip touchpad controller;
Yellow is another touchpad controller, Broadcom BCM5976;
Green - Apple A6 chip;
Blue - the vaunted Qualcomm MDM9615M LTE modem for both voice and data transmission;
Violet - multiband transceiver RTR8600, as in... Galaxy S III.

Any modern telephone will function normally only if all its systems work without interruption. This applies to both software and hardware devices. If the software has been flashed or updated improperly, then there is a big risk of seeing an error on the smartphone screen. Therefore, installing third-party programs and utilities is highly discouraged when using phones such as the iPhone.

By the way, it is iPhones that most often bring inconvenience to their owners. It's not that Apple produces low-quality products. On the contrary, the phones of this manufacturer are considered one of the most durable and reliable devices. The problem is that users very often install applications on their smartphones that are not compatible with the iPhone system. Most often, the owners of "apple" products are faced with error 21. Let's take a closer look at what this may be due to. How to fix the situation?

Causes

If error 21 appears on the phone, then this is not the most dangerous problem. However, it brings many inconveniences. Such a code may appear on the phone screen if:

• An error occurred while downloading updates. Error 21 is especially common when updating iTunes packages.
• iTunes registries have been damaged, for example, if the owner of the phone updated the software manually.
• A virus has broken into the software. Most often, this happens due to an unsecured operating system installed on the computer.
• A program conflict has occurred. For example, if the user installed a new utility that removed or blocked some of the files associated with iTunes.

There are a lot of factors that can affect the operation of the system. In addition to error code 21, owners of modern smartphones often encounter other number combinations that appear on the device screen. However, most of these errors in one way or another are usually associated with a failure in the software update process.

Creating a backup

Before you start any manipulations with the phone, you need to copy all important information from it. Of course, for this you do not need to rewrite everything in a notebook. Enough to create a backup. Fortunately, the iPhone allows you to do this very quickly. In order to save files from a smartphone, you must:

• Connect phone to PC.
• As soon as the computer recognizes the device and notifies you about it, you need to right-click on the icon.
• Select "Create a copy" from the context menu.

Standard reset

This method is a universal way that will get rid of the "glitches" of the smartphone. However, it should be borne in mind that when resetting the settings, all user information (pictures, photos, videos and other files) will be completely deleted. That's why it's so important to create a backup first. It is also recommended to immediately download the latest versions of iTunes and iOS from the official website of the manufacturer.

After that, you need to perform the standard firmware as follows:

• Go to the iCloud section and turn off the iPhone search function. If the phone version is below 5, then this step is not needed.
• Connect your smartphone to PC and turn on iTunes. The program may start automatically.
• Next to the iTunes Store button there will be an icon with the image of the device. You need to click it and go to the settings.
• Click on the "Restore via iTunes" button and at the same time hold down the Shift key on the computer. If the recovery is carried out through a Mac, then hold down Alt.
• The following dialog box will appear on the screen, in which you must specify the path to the previously downloaded fresh OS files.

After recovery, the device will enter Recovery Mode. The settings will be reset to factory settings. At the next stage, it will be possible to return the files from the backup to the phone. If error 21 appears again, then continue.

recovery mode

In this mode, you can also try to fix the error. True, in this case, you will also have to first save all the necessary documents and contacts from the phone book.

• Disable device.
• Press and hold the Home key.
• Without releasing the button, connect the smartphone to the PC.
• The media player icon will appear on the screen, and the system will report that the gadget has switched to Recovery Mode.
• If iTunes does not download automatically, you must force the program to start. A notification should appear on the screen stating that the device has been recognized by the media player.
• After that, the same steps are performed as in normal mode recovery.

At the final stage, you must specify the path of the new firmware and enter the Apple password.

Summing up

If error 21 on the iPhone has not disappeared, then the problems may be more serious than it might seem at first glance. In this case, you need to contact a specialized service center and diagnose the device.

It may happen to you that you are trying to restore your iPhone, but no matter what you do, the iPhone will not be restored because iTunes Error 21 or iPhone Error 21 keeps popping up! It's like whack-a-mole, you keep trying to restore, but that hellish iPhone Error 21 comes up again. Typically, these errors are the result of some security software package interfering with your recovery, and this usually has an easy fix.

So here we'll show you 8 different ways by which you can fix iTunes Error 21 or iPhone Error 21, recover with ease, and keep using your device!

What is iTunes Error 21 (iPhone Error 21)?

Now, before we get to the nitty-gritty of how to fix iTunes Error 21, I'm sure you must be won-Dering what iTunes Error 21 (iPhone Error 21) to start with, and why it has this weird obsession with your phone! The most common reason for iTunes error 21 is that your iTunes is trying to download recovery files (.ipsw) but is unfortunately being blocked from authentication. This may be due to a hardware error, or there may have been a communication failure between the device and the server. However, don't worry, we'll show you how to fix this iPhone error 21 easily and effectively and get back to leading your iPhone consumed life!

Solution 1: How to fix iTunes error 21 or iPhone error 21 without data loss

One of the biggest concerns you'll probably have when trying to restore yours and trying to fix iPhone 21 errors is whether or not your data is safe. It's a legitimate concern as many methods out there can or will certainly result in data loss. That's why we start our list with a technique that can ensure there won't be any data loss. To ensure this you can use a very easy to use and user friendly software called dr.fone - iOS System Recovery.

Your memories and data are all precious and you shouldn't risk them. dr.fone seems to put a lot of emphasis on saving data and as such is a recommended remedy for fixing iPhone Error 21. Besides, its user-friendliness and military-universal nature helps as well.

Steps to fix iTunes error 21 with dr.fone

Step 1. Select "iOS System Restore"

After launching dr.fone toolkit, you will find "iOS System Restore". Click on it.

Step 2 Connect iPhone

Connect your iPhone via cable and let dr.fone detect it. Click the "Start" button to continue the process.

Important: Please note that when fixing the issue - iPhone stuck on Apple logo, the IOS operating system on your iPhone will be updated to the latest version. And if the device is jailbroken iPhone, then it will be converted back to no jailbroken state.

Step 3 Download Firmware

dr.fone will detect your iPhone model and suggest the latest iOS version for you to download. Just click on the "Download" link and wait for the process to complete.

Step 4 Fix iTunes Error 21

Once the download is complete, dr.fone will automatically start iOS repair, except this time you won't be bothered with iPhone error 21 message!

Solution 2: Restart iTunes to fix iTunes error 21

Now this is just a nominal measure that you can look at, akin to how sometimes turning it off, switching to the computer fixes some problems. If there is a real problem, this method will be helpless in front of it, but if the iPhone error 21 is a temporary glitch, this should take care of it. Do you remember, as I said before, that iTunes error 21 is the result of iTunes being blocked. Well, sometimes just restarting iTunes and then starting the recovery process again might be enough to fix iTunes Error 21. So you might want to' lead with that.

Solution 3: Fix iTunes Error 21 by updating iTunes

Updates to all Apple products may be needed as they help fix bugs and whatnot. So if you've been keeping on updating your iPhone because you have a slow network, or because your phone is jailbroken or for whatever reason you might have, now is the time to update it. Get the latest version of iTunes and you may be able to fix iTunes Error 21.

How to Fix iTunes Error 21

1. Open iTunes.
2. Go to Menu > Help.
3. Select Check for Updates.

Solution 4: Turn off Anti-Virus to fix iPhone error 21

Many times the proper functioning of certain vital programs can be hampered by anti-virus as they can be corrupted or be threats. In this case, turning off the Anti-Virus helps to access these programs independently and possibly update the device.

Solution 5: Remove unnecessary USB devices

You can try to fix iPhone Error 21 by removing all unnecessary external devices from your computer, as they may have programs that get in the way of proper recovery and bring-ki to iPhone Error 21.

Solution 6: Check the sensor cable

This method sounds like complicated or risky. However, it is not, not unless you do it exactly the way it should be done. It's sorta like defuse a bomb, cut the wrong wire and the device goes boom! Well, not literally, but you get the picture. However, if you do it right, you may be able to fix iPhone Error 21. All you have to do is open the device, confiscate the screw that connects the battery. Disconnect the device cable and put it back together. This can help, although it seems like a rather extreme and risky measure, especially given that you have a much more secure and acceptable option in dr.fone from .

Solution 7: How to fix iTunes error 21 via recovery mode

This method involves you trying to fix iPhone Error 21 through DFU mode. DFU stands for device firmware update and provides full iPhone recovery. Although it guarantees fixing iPhone Error 21, it does not guarantee that all of your data will be safe. Thus, only use this method if you have exhausted all other options. Here is how you can do it.

Fix iTunes Error 21 or iPhone Error 21 via Recovery Mode

Step 1. Put your device into DFU mode.

Step 2 Connecting to iTunes.

Connect your iPhone to your computer and access iTunes.

Step 3 Restoring iTunes.

1. Open the "Summary" tab in iTunes, and then click the "Restore" button.
2. After recovery, the device will restart.
3. When asked to "Slide install," just follow the install.

This solution is most likely to fix iPhone Error 21, however, as I said earlier, it restores your phone to factory settings without giving you the option to create a backup. This will result in significant data loss, unlike the dr.fone alternative.

Solution 8: Check for modified or outdated software

iTunes error 21 can be caused due to outdated or corrupt software. You may be using an older version of iTunes, in which case you should refer to and update it. Perhaps you are trying to install an older version of IOS, in which case you should find the latest version and install that.

Conclusion

In listing the various methods by which you can fix iPhone Error 21, we do not discrimi-NAT between the various methods. We believe that you should have the maximum strength of a decision, which is why we have listed them all, along with their pros, cons, as well as risks. For example, some of the methods are significantly risky and can result in severe data loss, some of them can even destroy your iPhone if not handled well, and most of them offer no guarantee of success. So my personal recommendation is to go with dr.fone as it is a guarantee against all the risks I just mentioned. But hey, the choice is in your hands! We just hope you make the right call and then make a general one below so we know which method works best for you!

Happy owners of the iPhone are repeatedly contacted with the procedure for updating or restoring the device they bought through the official program from Apple - iTunes. However, some serious troubles can sometimes occur when restoring, and one of them is error 21, which occurs on both the iPhone 5S and iPhone 4S. This unknown error prevents the user from performing the procedure he needs, and as a result, a person sees information on the monitor screen - "Failed to restore iPhone."

What is error 21

This problem, according to experienced specialists, is connected precisely with interruptions in the hardware of their own gadget. This error could be caused by malfunctions of the modem, internal boards, and so on. With a small bump or fall, the iPhone may be outwardly perfect, but inside with some kind of microcircuit, unpleasant consequences could occur, which in the future led to error 21.

iTunes error 21 - ways to fix the problem

Although error 21 occurs exclusively with mechanical damage, there are actual methods that sometimes help to cope with this problem at home.

List of useful recommendations from experts:

• Install new drivers on a PC or laptop;
• Use the latest version of iTunes;
• Make sure the cable is working;
• Restart your computer;
• If you have experience and the necessary skills, try to change the firmware on your iPhone yourself;
• Finish the update (restore) procedure on another personal computer.

If none of the above proposed manipulations helped in solving this problem, then it is definitely necessary to contact professionals who repair mobile equipment. However, do not think that you will have to pay a large amount for, there is a possibility that the software elements are incompatible and the specialist will only select a new firmware.

Conclusion

Updating and restoring iPhone is an important procedure that is used by a huge number of people around the world. And, if any errors occur during the process, before contacting the help of specialists, you can carry out some procedures personally in order to save money. But if nothing happens during the process, it’s better not to be a hero, because there is a chance to make it worse.