Why does my iPhone have a black screen after attempting to downgrade?

Adam Fenyvesi December 23, 2011

I was doing a downgrade on my iPhone 4 when the downgrading stopped at the middle with the system saying “error 1600”. Now my iPhone has a black screen and I can’t turn it on. When I connect it to the computer, iTunes automatically says the device is in recovery mode, and I have to restore it. If I want to restore it normally with the simple iTunes I have other problems with “error 3194” or “error 2005”. I don’t know what to do now, please help me.

  1. Nathanrist
    February 17, 2012 at 11:50 am

    you need shsh to downgrade. error 1600 is an incompatible firmware and your device is in DFU mode which explains the recovery message and black screen. if you have shsh for the version your downgrading toyou have to put into pwned DFU mode, option/shift click restore and select your firmware .ipsw file, you may need to use recboot to kick out of recovery also

  2. Mike
    December 23, 2011 at 6:24 pm

    iOS is not meant to be downgraded. If you rely on jailbreak or whatever simply don't upgrade iOS before a working jailbreak is released and approved by the community.

  3. Anonymous
    December 23, 2011 at 4:56 pm

    you can try this under your responsibility
    How to Fix Error 3194, 1602/04, 1013/15 When Downgrading From iOS 5 to 4.X (Windows)