Honestly speaking, if you like updating your iPhone every now and then, you might be facing many small software issues while downgrades or jailbreaks as I usually face. I take it for granted that I will need to do some kind of troubleshooting while jailbreak, upgrade or downgrade on my iPhone 3GS. Incidentally, about 80% of the times, I have to do some or the other kind of troubleshooting in between as the process is not always smooth. Today I downgraded my iPhone 3GS on old bootrom from iOS 6.0 to iOS 5.1.1 using the Redsnow tool and it landed me in some troubles in the middle by throwing some unexpected errors with error codes “Unexpected error 2601” and “Unexpected error 2624”. In this article, I share with you how you can avoid or troubleshoot these errors.
First of all, you will see these errors if you are trying to downgrade the iPhone OS on an iPhone using IPSW restore method on an iPhone. All the detailed steps of this tutorial are explained by iClarified here. In my experience of this downgrade tutorial, I got stuck at step 8 after selecting the IPSW file, the process moves a bit further and it stops with unexpected error 2624. I also tried one older version of the redsn0w, but it also failed with error code 2601 which was a different error this time.
After doing some research online and hit and trial, I finally found a word around which worked for me. Actually there are two possible ways to solve this error, I will share both one by one.
Solution 1: First solution involves turning off the firewall of your computer. This maybe required because while doing a downgrade, the redsnow tool communicated with Cydia servers and the communication might be interrupted which causes the process to get interrupted and thus these unexpected errors. Turning off the firewall may solve the issue for most users, but the solution did not work in my case.
Solution 2: While you follow the solution 2, we suggest you to keep the firewall turned off. The solution 2 involves opting to not preserve the baseband in the tutorial after selecting the IPSW. Now the catch here is that if you have upgraded to iOS 6.0 and have preserved your lower baseband version, then you must preserve lower baseband, but if like me, you have already updated to the baseband of iOS 6, then you will see the errors 2624 or 2601 as I faced.
NOTE: If you need to unlock using ultrasn0w or other such tools, you must NOT follow the solution 2.
If you have a factory unlocked phone and you don’t need an unlock, you can opt to not preserve the baseband in the step after selecting the IPSW file while downgrade process. This will make sure that you will not be interrupted in the process.
After I selected to not preserve the baseband, the process continues normally and the iOS version restore using the redsn0w worked fine.
Hope you find the tutorial useful. Check out some more iPhone Tips and Tutorials by Trouble Fixers.
NOTE: This tutorial is for advanced users who know what they are doing, in case you are not sure of the iOS version and baseband version of your device, we suggest you to take some expert help. We are not responsible for any damages (if any) to your computer or iPhone. Also jaibreaking your iPhone is legal but may void warranty, we do not recommend the use of any illegal software.