Recently, many of our readers have been reporting about iTunes erroring out with the 3194 error code while they try to restore/update their iOS via iTunes. Also, many a times, readers have ended up in an infinite DFU loop inspite of a successful restore. So rather than explaining to each one what this is all this about, I have put up this informative article that will help you understand & resolve these issues in future.
What's Error 3194 All About?
Inspite of my fellow colleague Tikes's simple yet extensive post here at Jaxov, people still seem to have a hard time trying to resolve the 3194 error. In short, this error code has anything and everything to do with the SHSH blobs saved for your device. May it had been saved via Cydia or via TinyUmbrella, SHSH blobs are always a necessity if you ever plan to update/restore your iOS to any version other that the latest available version pushed out by Apple OTA. For a much more detailed explanation about the SHSH, I would suggest you to read Tike's post first & get back.
DFU Loops After A Successful Restore from iTunes
DFU loops occur inspite of a successful restore from iTunes simply because of invalid SHSH blobs. You must know by now that Cydia is no longer able to proxy your SHSH blobs reliably if you were to use Tiny Umbrella for your SHSH saves. If you were able to boot your device by using Redsn0w's tethered boot option, once your device is unhooked or rebooted, its back to the loop. This is because the iPhone's bootrom places an explicit check for a valid SHSH & when it doesn't find one, your put into a DFU loop. Without a valid SHSH blob, you cannot expect it boot untethered now can you? (All tethered jailbreaks do not have an SHSH)
Check for Saved SHSH Blobs first: You can restore/upgrade to an iOS version ONLY with the help of a saved SHSH blob. If you are jailbroken already, fire up Cydia & check the top portion of the homepage.
You should now be able to see a list of iOS versions. These are the SHSH blobs that have been saved for your device by Cydia and are the ONLY iOS versions to which you can restore to. In this example view, I'm missing my 4.0.x/3.x.x SHSH blobs, meaning I cannot restore to those versions of the iOS anymore. So, if you can't find an iOS version listed here but you were willing to restore to that version anyhow you will end up with the 3194 error if attempted.
If you are in a DFU loop already: Chances are that Cydia has auto-saved the SHSH blob for the iOS version on which you were right before you attempted the restore or update (only if you ever were jailbroken). This happens if Cydia was able to save one for your device while it was still being signed by Apple for official restores.
NOTE: Make sure that you also enable the Request SHSH from Cydia option from TinyUmbrella's Advanced menu & then hit the Save SHSH button. If you do not find any SHSH blobs via TinyUmbrella continue reading..
1. Use iFaith to Save SHSH Blobs:
We really cannot shout any louder than this. Save your current SHSH blobs using iFaith. This is an important step for those who have never jailbroken their iDevices or have never saved any SHSH blobs for their devices via Cydia or TinyUmbrella. Performing this step gives you the added advantage of being able to restore back to your current iOS version in case something goes wrong with the iTunes restore. Read this guide to learn more on how you can save them using iFaith.
iFaith is only for those who are currently able to run an iOS version (4.3.3 & below) on their iDevices without any issues. If you are stuck in a Recovery/DFU loop because of an attempted update/restore via iTunes or if your on any of the later iOS versions, iFaith is useless.
2. Avoid using TinyUmbrella for your Restores Completely
DFU loops (pitch black screen after a successful restore) occur due to invalid SHSH blobs signatures. Sometimes when you try to restore via TinyUmbrella (especially with a Snowbreeze custom IPSW), your device will go through a forced restore thinking that it now has an SHSH for itself to complete the process. Once its completed, your reboot fails and your device will be kicked back into a DFU loop. The only way to avoid this issue to use TinyUmbrella ONLY if you want to save an SHSH blob for your device locally onto your computer. Also, you still can use TinyUmbrella to perform a restore, but ONLY to take advantage of those locally saved SHSH blobs (TSS Server mode).
So if your using TinyUmbrella to restore thinking of an SHSH blob that's currently not saved on your local machine, Do NOT use it.
3. Get your SHSH Blobs by Editing the HOSTS File
If you believe that you have saved an SHSH blob for your device earlier but still TinyUmbrella is not displaying it, you need to take advantage of your edited HOSTS file. By redirecting iTunes to Cydia's server for a restore, you will be able to restore with success using the saved SHSH blobs on Cydia. If you do not know how to edit your OS hosts file, I recommend you to read Tike's post once again. Performing restores in this manner will always result in a successful restore without any 3194 error.
NOTE: If in case iTunes error 3194 is still returned, it simply means that you do not have the necessary SHSH blob saved for that version even on Cydia to which your trying to restore to. You really cannot do anything about it.
Please drop in your comments down below if I have missed something. :)