Error 1600 is reported by many users who tried to restore the custom iOS 4.1 firmware cooked with PwnageTool. As you know PwnageTool lets you to install the latest iOS firmware without changing / updating the baseband and if you don’t rely on unlock, the best solution to get rid of error 1600 is to use the other available jailbreak tools like Redsnow, Greenpoison and Limera1n.
However if you rely on unlock and don’t have any choice other than using PwnageTool, make it sure that you follow all the steps properly to burn the custom firmware.
The main reason of error 1600 is that users don’t put the idevice into DFU mode according to the instructions mentioned on the screen of PwnageTool during the restoration process.
Solution:
Solution is simple. Retry after putting the idevice into DFU mode properly. So, you should make it sure that you press the correct buttons in correct order and release the specific button after specific time to get into DFU mode and to avoid such problems.
Thanks for the info I just wasted 3 hours of my life before finding this page.
Man I cooked my custom firmware with this tool. I have iphone 3G 16Gb, after customize the firmware I entered in DFU mode but always with same error 1600 when I wish to restore my custom from iTunes. Do you know if there is any way to do anything else? Of course I need to unlock my custom with ultrasnow.
Thanks man, you saved my day