I get an unknown error 21 when restoring iphone or ipad. itune is updated to the new version and iOS is also updated. I also deleted the ipsw file and still gets the error. Anyone have an idea or had the same problem?
MacBook Pro, Mac OS X (10.6.6)
Error 20, 21, 23, 26, 28, 29, 34, 37
These errors typically occur when security software interferes with the restore and update process. FollowTroubleshooting security software issues to resolve this issue. In rare cases, these errors may be a hardware issue. If the errors persist on another computer, the device may need service.
I had the same problem. Issue started when my iphone4 blacked out on me. I upgraded to ios6 a month ago. I would get the apple logo flashing when I plugged it in my laptop. Then I did DFU to restore and it would get to an unknown error (21). Googled some fixes and found that opening the device and unhooking the terminals for the battery would fix it. YouTubed videos on how to disassemble iphn4 and figured i take it to the Store for official help. I got a sales pitch to replace (swap) my existing device with a new one - same model - for $149. Or do an upgrade with a 2 year contract via the carriers. Decided to take the risk of fixing it myself. Followed the instructions for the fix, did a restore and no more unknown error 21. Device back in service.
I have the same problem trying to restore my iPhone 4 (5.1.1) and when iTunes download the update and then restore it gives me error 21 ,, i am exauhsted i couldn't find a fix for that,, if you may help ,, i just watched a vid on yt how to disassemble an iPhone what do you mean by unhooking the terminals for the battery ?
unknown error 21 when restoring iphone or ipad
