Fix for iTunes error 1600 when restoring 3.1.3 to 3GS
Sometimes when trying to restore a custom firmware to an iPhone using iTunes you get hit with an error 1600. There are a variety of causes but in my particular case, I screwed up the phone trying to change fonts and it wouldn’t boot. I turned to google and found about a million threads with various suggestions on how to make it go away. But none of them worked for me.
(There is a handy tool called iReb that will fix this issue for iPhone 2G and 3G, but it doesn’t work for the 3GS.)
And of course Apple stopped signing all previous firmware versions and restoring to official 3.1.3 would update the baseband, making it *currently* un-jailbreakable and unlockable. So, what’s one to do..I tried everything! Well, almost everything…
I was desperate and thought of one last thing to try. I put the phone in DFU mode and started an official 3.1.3 restore. It extracted the software and went to “preparing iPhone for restore.” At this point I saw an Apple logo on the phone. More waiting, and then I saw an empty progress bar appear on the phone. I continued waiting through the “preparing iPhone for restore” stage and the progress bar remained empty. Finally, after what seemed like several minutes the status changed to “waiting for iPhone.” I immediately unplugged the USB cable. The phone then rebooted into Recovery mode (or I rebooted it, don’t recall) but either way I knew that this was a step forward because I couldn’t even get it into Recovery mode before. At this point I force quit iTunes, restarted iTunes, and was able to restore my custom firmware!
The restore completed successfully and my baseband was not updated. Great success! Now I’m not sure if this has been attempted before but I haven’t seen any mention of this anywhere on the interwebz. Try at your own risk of course, but if you need this you’re probably desperate anyway. In that case, hope this helps. At the time of this writing I’ve used this method twice, both with iTunes 9.0.3, once on a Mac and once on Windows. Yes, I’ve been screwing with my phone quite a bit.
