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Level 1

4 points

Unexpected shutdown of iphone

After putting in recovery mode and then restring, I get: "The iPhone “iPhone” could not be restored. An unknown error occurred (21)."

Posted on Jan 9, 2022 8:29 PM

Top-ranking reply

Level 6

17,696 points

Posted on Jan 9, 2022 9:09 PM

Could be a hardware malfunction.

iOS update and restore errors - Apple Support

If you see one of the errors below, you might have a hardware issue:

1, 3, 11, 12, 13, 16

20, 21, 23, 26, 27, 28, 29, 34, 35, 36, 37, 40, 56

1002, 1004, 1011, 1012, 1014, 1667, 1669

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