In light of Apple stopping signing the OS 3.1.2 firmwares, you now need a saved SHSH file that Cydia has been backing up for a while now. If you have allowed Cydia to backup your SHSH BEFORE that past few days, then you will still be able to downgrade your device back to OS 3.1.2 from OS 3.1.3. Here is how to do it.
As I said, you can ONLY do this if you click make my life easier on Cydia before yesterday which allows Cydia to backup your SHSH file. You should see this when you launch Cydia.
To downgrade your firmware you will need to change a line in the hosts for Cydia redirecting iTunes to download the signature file from Saurik’s server rather than Apple’s.
Guides are courtosy of ihackintosh.com:
How to Edit and Save Hosts file in Windows
- Open Notepad with Administrative privileges by clicking Start, All Programs,Accessories, and thenright-click Notepad and select to open as Administrator.
- Now that Notepad is open with Administrative privileges browse to (C:WindowsSystem32driversetc) in Notepad and open the hosts file, and add the following entry to the bottom of the file.
74.208.10.249 gs.apple.com
Now you navigate to files menu and save the hosts file. By doing this you changed the communication server, and then we will ensure that iTunes checks the firmware on the server rather than opens Saurik toApple! Because your ECID is on that server, the verification will fail and restore the previous version will be done without too many problems!
_____________________________________________________________________________________
How to Edit and Save Hosts file in Mac OS X
- Navigate to /etc and look for hosts file, right click on hosts file and open with Text Edit, and add the following entry to the bottom of the file.
74.208.10.249 gs.apple.com
- Now save the file and click on Save As.
- Because Text Editor can’t save your system files, here comes the tricky part, in save as windows use the following settings. Or take a close look at the following image.
- In Where locate to Desktop
- Uncheck the “ If no extension is provide, use .txt “ and then press the save button.
- A host file will be appear on your Desktop, just drag and drop to /etc and follow the onscreen instructions.
- Press the Replace and enter your Password
By doing this you changed the communication server, and then we will ensure that iTunes checks the firmware on the server rather than opens Saurik to Apple! Because your ECID is on that server, the verification will fail and restore the previous version will be done without too many problems!
You will now be able to downgrade your device to OS 3.1.2 from OS 3.1.3.
Simply place your device into DFU mode and click SHIFT+RESTORE, select your firmware file and you will be downgraded.
If you receive 1011, 1013, 1015 errors simply ignore them as your firmare is still properly installed. Just go ahead to Blackra1n or Redsn0w and jailbreak your device.
If you receive 1601, 1602, 1600 errors, you will need to put your device into DFU mode once again and try install the firmware once again.
And if I don’t have the SHSH Cydia files backup???
Because it was a new iPhone and I didn’t jailbreak it yet, just installed and it upgade to 3.1.3.
Now i have to downgrade to jailbreak.
Can you help me???
No I’m afraid that means you are stuck on OS 3.1.3 until another hack or jailbreak comes out. Sorry man.
Hi
i have ECID from my 3gs with jailbreak firmware 3.1.2.
now i have (sighhh) upgrade to orifinal 3.1.3.
i can create my SHSH with iREB and send it to saurik server for downgrade to 3.1.2 original?
how?
please can you hel me?
bye bye
I’m not sure what you mean. Back when you had jailbroken 3.1.2, did you click the button on Cydia saying make my life easiser or did you not accept it? Or have you saved the ECID manually onto your computer?
Hi
no i get ECID with grab and make SHSH with umbrella.
i try use localhost fow validating and validation is ok but the firmware not downgrate, itune error 3002 or 1600
uff
You are going to need to follow this guide to set up a local way of doing it: http://modmyi.com/forums/3g-s-downgrading/685331-howto-setup-local-3gs-restore-verification-server-ecid-shsh.html
I have 3gs, os 3.1.2 install and jailbroken with balckra1n… when phone resprings or reboots it hangs. I tried to re jailbreak with black rain but still no luck. Restoring it can only be done with apples new 3.1.3. This just happend today. Now I never saved the ECID but tried to restore with redirecting the host, again with no luck, apples just wants to restore to 3.1.3.
Its still at 3.2.1 but unusable
Any ideas would be gratly appreciated
I’m not quite sure what you mean by it hangs when you reboot it. Does it not turn on at all? What was the last thing you did before it stopped working. Did you just install something?