Some of you might have noticed the annoying 1604, 1600 error when restoring to iOS 4 custom firmware in Tunes which built using PwnageTool 4.0 or 4.01. The error in question looks something on the lines of this.
The iPhone “[your iPhone]” could not be restored. An unknown error occurred.
Going through the comments posted here, I found this fix posted by one of our reader which I thought I should share it with you all. I haven’t tried it because I never got the error, but if you did get the error, let us know if the instructions posted below fixes the issue.
The instructions, as posted by Carlos Leopoldo are as follows.
Steps to fixing 1604 iPhone restore error:
1. There is no need to reinstall iTunes or whatever. Keep the same version that you have used to restore or backup previously.
2. Make sure that iPhone is disconnected from your computer and that iTunes is closed.
3. The following step of fixing 1604 iPhone restore error is Windows XP specific, if you are a Mac user, you may have to locate the folders yourselves as I am not sure: Go to folder C:Documents and Settings<username you use to login to windows>Application DataApple ComputeriTunesiPhone Software Updates. You will see one or more files. Cut and paste them somewhere else. Do not delete them in case the steps does not work for you, you can still copy them back to the folder. You can find out your username by doing a Ctrl-Alt-Del. If somehow you cannot find the folder, you are probably in the wrong user directory.
4. Launch iTunes and put your iPhone in recovery mode. Refer to this article on Unable To Restore iPhone on how to do put iPhone in recovery mode.
5. Proceed with restore and iTunes will download the update online. If you are downgrading to a lower version, do step 3 and leaving only the firmware file that you want to downgrade to. Double click on the file and iTunes will begin the restore.