Unknown error 21 occurs on restoring / updating iPhone 5.

Asked By Warren N Garner 0 points N/A Posted on - 12/28/2014

I have an Apple iPhone 5 that has iOS 7 in it. Last night the phone automatically reset itself and wouldn't turn on. I plugged it into the computer and the connect to iTunes screen appeared. I connected it and tried to restore my iPhone but an unknown error 21 occurred. I tried it on different laptops but to no use. How can I fix this? Can I update my iPhone directly?

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Best Answer by Clare Moui

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Answered By Mano Fren 0 points N/A #191447

Unknown error 21 occurs on restoring / updating iPhone 5.

Hello,

Step 1.

You just take off back disconnect the battery (one screw).

Step 2.

Then you should hold the home button down for 30 seconds or more to help fully reset the phone,then push the silver connector back on and put phone together. 

Step 3.

Now hold down home button and same time plug it into the computer and keep holding the home button until phone shows to plug into iTunes. 

Step 4 – Last Step

Then do a complete restore and your phone will be like a new one. 

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• Posted on - 12/29/2014
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Answered By Clare Moui 0 points N/A #191446

Unknown error 21 occurs on restoring / updating iPhone 5.

This is not severe problem. For solving this kind of issue try below solution.

1. Took off the back plate and disconnect the battery from the iphone.

2 The battery looks intact (no leaks or signs of damage), then just place the same battery again and turn the phone back on.

3. It allows you to do a restore, and you will be able to back up all your info from the cloud.

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• Posted on - 01/29/2015
• Question Category: iPhone