Home News Troubleshooting Failed To Restore IPhone 4 Error 21

Troubleshooting Failed To Restore IPhone 4 Error 21

29
0

 

In this blog post, we are going to identify some possible causes that might prevent the iphone 4 error 21 fix. Then I will suggest possible solutions that you can try to fix the problem. The most common cause of iTunes error 21 is when iTunes tries to download recovery files (.Ipsw), but unfortunately blocks authentication. This could be due to a hardware failure or communication failure between your device and the servers.

 

 

Learn how to troubleshoot iOS update and restore issues.

Try These Steps First

  1. On a Mac with macOS Catalina 10.15, make sure your Mac is up to date. If you have a Mac with macOS Mojave 10.14 or earlier, or a PC, make sure you have the latest version of iTunes installed.
  2. If the device cannot be restored and you receive an “unknown error [error number]” message, follow these steps.

If the error persists, try the following.

Choose Your Number Or Error Message

Select your fault to find out what to do:

  • 1, 2, 3, 4, 6, 9, 10, 11, 12, 13, 14, 16, 17
  • 20, 21, 23,26, 27, 28, 29, 34, 35, 36, 37,
    40, 53, 56
  • 1002, 1004, 1011, 1012, 1014, 1015
  • 1600, 1601, 1602, 1603, 1604, 1611, 1638,
    1643-1650, 1667, 1669, 1671
  • 2001, 2002, 2005, 2006, 2009
  • 3002, 3004, 3013, 3014, 3015, 3194, 3200
  • 4005, 4013, 4014, 4037
  • Update The Software On Your Mac Or PC

    If you see error 10, your iOS device may have a newer version of iOS than your computer supports. You need to update the software on your Mac or iTunes on Windows before you can update or restore your iOS device.

    macOS 10.11 and up:

    1. Disconnect your iOS device and reconnect it to your computer. You may need to unlock your iOS device before your Mac can recognize it.
    2. If you find that a software update is required to connect to your iOS device, click Install to download and install the software so your Mac can update or restore your iOS device.

    Windows: updUpdate iTunes to the latest version.

    If you still see error 10 or don’t see the dialog box asking you to update the software on your Mac, contact Apple Support.

    Make Sure Your Device Can Communicate With Apple Servers

    If you see error 1671, your computer is downloading the required software. Wait for the download to complete and try again.

    If any of the following errors occur, your computer may not connect to Apple servers or to your iPhone, iPad, or iPod touch:

      17, 1638, 3014, 3194, 3000, 3002, 3004, 3013, 3014, 3015, 3194, 3200

    • “There was a problem downloading the software.”
    • “The device is not authorized for the requested build.”

    Check the following:

    1. Make sure your computer can communicate with Apple’s software update servers.
    2. Check third party softwaresecurity.

    If you see error 4037, your computer cannot update your device because the password is locked and the device has not been unlocked for updating or restoring. Unlock your device and try again. Find out what to do if you forgot your password.

    If the error persists, contact Apple Support.

    Failed To Update Mobile Phone Or Apple Pay Alert Is Not Available

    If, after updating, you get the message “Cellular update failed” or “Apple Pay requires updating on this iPhone,” please tell me what to do.

    Check Your Security Software

    Check Youro And USB Connections

    If you see error 4005, 4013, or 4014, follow these steps.

    If you encounter any of the following errors, check your USB connection, USB cable, USB port, or computer:

      13, 14, 1600, 1601, 1602, 1603, 1604, 1611, from 1643 to 1650

    • 2000, 2001, 2002, 2005, 2006, 2009
    • An error containing an “invalid response”.

    Here’s what to check. Please try again after each step:

    1. Use the USB cable supplied with your device. If you don’t have one, try a different Apple USB cable.
    2. Switch to a different USB port on your computer. Do not plug it into a keyboard.
    3. Switch to the USB port on the other computer.
    4. If the error persists, check for other USB issues, check third-party security software, and then check your hardware.

    If the error persists, contact Apple Support.

    Check Your Stuff

    If you see error 53, try the followingtviya.

    If one of the following errors occurs, there may be a hardware problem:

    • 1, 3, 11, 12, 13, 14, 16
    • 20, 21, 23, 26, 27, 28, 29, 34, 35, 36, 37, 40, 561002, 1004, 1011, 1012, 1014, 1667, 1669

    Here’s what to check. Please try again after each step:

    1. If iTunes is already open, close and reopen it.
    2. Check third party security software.
    3. Make sure your USB cable, computer and network are reliable. Then try restoring your device two more times.
    4. Check for outdated or modified software.

    If the error persists, contact Apple Support.

    could not be restored error 21 iphone 4

    Check Outdated Or Modified Software

    Release Date: Â

    Learn how to troubleshoot iOS update and restore issues.

    Release Date: Â

     

     

    How do I fix the activation error on my iPhone 4?

    Reasons You Can’t Activate Your iPhone
    1. Activation lock is set.
    2. You may be having problems with your network operator.
    3. The activation server may not be available.
    4. Your SIM card may not be supported.
    5. Activation could not be completed.
    6. Check if your iPhone has a SIM card.
    7. Wait a bit
    8. Remove the SIM card and insert it again.

    Why will my iPhone 4 not update?

    Reasons You Can’t Activate Your iPhone
    1. Activation lock is set.
    2. You may be having problems with your network operator.
    3. The activation server may not be available.
    4. Your SIM card may not be supported.
    5. Activation could not be completed.
    6. Check if your iPhone has a SIM card.
    7. Wait a bit
    8. Remove the SIM card and insert it again.

    How do I fix Error 29 on my iPhone 4s?

    If you replaced the battery in your device, this could be a problem as iTunes showed you error 29. To fix error 29, you need to replace the battery with the original one and run the recovery process again. update via iTunes.