Recently, Many people have complained that their iPhone won’t restore. Some iPhone won’t restore after iOS 10 update. Due to error 21, some iPhone won’t restore.
What is Error 21
The most common reason for iPhone Error 21 is that your iTunes is trying to download the restore files (.ipsw) but is unfortunately being blocked from authentication. This may due to a hardware error.
Below given the solutions for iPhone 5 will not Restore in Recovery mode.
Solution 1: Use USB port
Found a steer elsewhere online that advised connect iPhone using a different PC USB port. Hopes it works.
Solution 2: Enter DFU mode
Enter DFU mode to fix iPhone stuck in recovery mode or restore mode:
- Plug your iPhone into your computer with USB cable.
- Turn off the iPhone.
- Hold the power button for 3 seconds.
- Hold the Home and Power buttons for 10 seconds.
- Release the power button but keep holding the Home button.
- After about 15 seconds you will alerted by iTunes saying that it has detected a device in Recovery mode.
Solution 3: Recovering lost data of iPhone in recovery mode
- Turn off your device, then turn back on.
- Plug your device into a PC and should detect your device is in recovery mode.
- Click the restore tab.
- Restore iPhone or iPad.
- Press and hold the power button for 5 secs.
Solution 4: Run iTunes
- Trying to restore it Say downloading updates or something, then ends it error out, can’t restore.
- Now plug it into a different computer, run iTunes and try again.
- The phone is in DFU mode, saying that it needs be restored.
Solution 5: If your iPhone won’t Restore after Update
- Update your iTunes to the latest version.
- Close out the anti-virus you might be running.
- Start your iPhone in the Recovery mode.
Solution 6: If your iPhone won’t finish restoring from iCloud
If the iPhone won’t finish restore from iCloud, check whether the WiFi connected correctly. There is a bug in iCloud that could result in the failure of restoration. Try to restore your iPhone.
Solution 7 : If your iPhone won’t Restore After Jailbreak
- Put iPhone into DFU mode.
- In iTunes Summary window, click the Restore iPhone option.
The above mentioned solutions resolve this issue.