Downgrade Iphone 4 iOS 4.0.2 to 4.0.1 without SHSH Blobs
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I have skimmed through all of the web looking for ways to downgrade iOS 4.0.2 to older iOS 4.0.1 firmware on your Iphone 4 3GS 3G without having SHSH blobs saved. Since many users didn’t have SHSH blobs to restore to older firmware 4.0.1 that had the “PDF Flaw” they cannot jailbreak their device. Those who want to downgrade can try this technique. However I must say , that this method has not been tried and tested by me , but you can give it a try to see if it works.
Steps to downgrade iOS 4.0.2 without SHSH Blobs :
- Download iOS 4.0.1 .ipsw firmware file
- Rename it to .zip and extract the .ipsw file using Winrar
- Now find the file named buildmanifest.plist and open using a text editor like Notepad
- Search and Replace all 8A306 with 8A400 using the shortcut function shown below
- Now Download iOS 4.0.2 ipsw firmware files
- Open with Winrar , but don’t extract . Leave it open
- Now take the files from iOS 4.0.1 and put them in the zip archive of iOS 4.0.2 you just opened
- Next step is to Delete all files with extension .dmg having “002″ at their name
- Now save the archive and rename it back to .ipsw (changes you made the at the time of extraction at step 2)
- Put your device in DFU Mode . Read DFU Tutorial
- Now open iTunes and restore the firmware
Read about : How to JailbreakMe Tutorial
Please let us know if this technique worked through your comments . Dont forget to Subscribe to our Jailbreak alerts to get more tutorials via email . You may join our Facebook Fan Page and share the word.
Update :
More than 17 users tried this method and posted their views. This method didn’t work for them on their Iphone 4 . I tried to find , if anyone was succesful with this method . Here is what i found on a blog [Firmware Umbrella Blogspot]
There is much discussion on many blogs about a potential means of downgrading iOS 4.0.2 to 4.0.1 by simply changing a couple values in the buildmanifest.plist and copying all of the images from 4.0.1 into 4.0.2 and then deleting the files ending with 002. Following all of this, perform a DFU restore and somehow you will be on 4.0.1.
There is a perfectly logical explanation for all of this and I will lay out exactly what is happening and explain why it is working for the folks that are the lucky ones.
Let me get this out first.
- This is not a miracle, at least not in the sense you all hope for
- SHSHs are STILL required for any iPhone 4, iPhone 3GS, iPad, iPod Touch 3G, and iPod Touch 2G (MC Model)
- There is NO way around this… unfortunately this method included.
Let me start by explaining something very important. The buildmanifest is used by iTunes to build much of the TSS request that is used to obtain your SHSH for any given firmware revision. Unfortunately, the BuildNumber has no part to play in the request for SHSH. All that you ended up doing in following these directions is request 4.0.1 SHSH blobs.THAT IS ALL. Since every single one of you that got this to work changed your hosts file to point to Cydia, Cydia responded to the TSS request with an SHSH blob that was ALREADY “on-file”. There was no magic. There was no miracle, apart from the lucky break that your device had been put on Cydia’s SHSH request list at some time in the distant past.
That’s it in a nutshell folks. There was no amazing technique for bypassing Apple’s TSS. There was no amazing exploit that exists in DFU mode allowing for 4.0.2 -> 4.0.1 downgrading. It’s simple; Cydia had your SHSH because at sometime in the past either:
- Someone saved your SHSH with that device using TinyUmbrella and the default options
- Someone restored that device with Cydia in the hosts pointing to gs.apple.com
- Someone jailbroke the device and pressed ‘Make my life easier’
Unfortunately we have to wait for any future release from the Iphone Dev team. Subscribe to get Updates on this topic.
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Has anyone tried this did it work?
Didnt work. says it does not reconize
Anyone have tried?!
Not working on Iphone4 with 4.0.2 no shsh saved.
no not working for me
Apparently works only with 3GS, and not even sure.
Once again disappointed to know that I can’t dowmngrade on my iphone4
. I am slso one of those “new iPhone owners” who never knew abt this jailbreaking and when I learned abt it, it was too late (I had already upgraded to 4.0.2) 
.
But I liked the overall idea of this post, get the 4.0.1, edit and make changes so that it “looks” like 4.0.2 to Apple servers so that when we try to install/restore it, the Apple servers will “approve” or “authorize” it thinking it is 4.0.2
So basically we are trying to install 4.0.2 in 4.0.1 disguise which is a good move to start with.
thanks Author, even though it didn’t work.
Sorry,
.
I meant “…we are trying to install 4.0.1 in 4.0.2 disguise…” in my prev comment
Didn’t work for my iPhone 4.
Wow I wish I could do this but I’m just a basic white redneck that’s not that smart can you make it easier ????
Sent from Jason’s iPhone
Sorry Jason , its just an experimental hack as the author said . It may or maynot work for all …
Tryed… does not work on iphone 4…
too bad… but I will wait new oprions!
Not sure if you want feedback on this, but anyway.
This works for all but the Iphone4.. 3G and 3GS is successful, but not 4, unfortunately since i got it out of the box with 4.0.2
Did not work for me… aslo changed 8a306 to 8a400 at restore.plist…no way… we need something else
Nope won’t work on the iPhone 4….su*ks
The idea is good but this is not successfully “cheating” the Apple servers that this is “4.0.2″ and not “4.0.1″.
.
I think someone needs to find the correct way of “confusing” Apple servers and my feeling the best people to find this quickly is the guys who developed the “jailbreakme.org” site…
Since we dont know anything, trial and error will take forever for us. The jailbreakme guys already know which files to edit so they might just come up with the solution pretty quick, provided they have time and intention to do it of course
It didn’t work for me either (iphone 4)
Spent two hours for downgrde get nothing to work on iphone 4.0.2 at all. Try next luck.
None Succeeded. I guess its time i must update the post and ask users not to try this method any further , hence avoiding more confusion.
Did you try it? did it work with you?
not working on my iphone4
still error 3194
how to fix? please help.
Well that is a shame that it doesn’t work but the idea was a good concept. My iPhone4 is being delivered soon and if it is sealed and the serial shows it was made anywhere near week 30, I’m sending it right back and I’m going to take the risk and buy one on ebay! I’d rather have no phone if it isn’t Jailbroken. I’ll just have to stick to my 3GS for now. Greedy little apple!
Shame.
Where there is a will there is a way. Give up now Apple; this community is better than you, has more resources than you and know what your customers really want. This will only end when Apple give in to public pressure and deliver the functionality users want.
doesn’t work
spent two days messing with this, still cant unlock the damn phone 4
Didnt try it as it looks like it didnt work! keep it comming guys
Please don’t try wasting time, it will not work for iPhone 4 out of the box IOS 4.0.2
iPhone 4 iOS 4.0.2 user from Cambodia.
have tried this method as well and doesn’t work.
error 3194 occurred!!
Admin, please e-mail the working method to my mail if you happen meet one that work for 100%.
Thanks.
I’ve also got an Iphone 4 with iOS 4.0.2, and it seems completely impossible to downgrade – with or without blobs.
I guess I’m just left to hoping that there will be developed a jailbreak for iOS 4.1.
Hi for all,
I have same problem with 4.0.2, who can HELP me????
pls.
This method only works if you were on iOS 4.0.1, saved the SHSH blobs and upgraded to iOS 4.0.2. As of Sept 28th 2010, there is no way to downgrade the iPhone 4 on iOS 4.0.2 down to iOS 4.0.1 without the SHSH blobs. We just have to be patient and wait for the iOS4.1 jailbreak, but it should not be long now.
I tried the method above carefully and it does not work. It fails the check (error 3194) when it tried to talk to the Apple server with the modded ipsw file. Redirecting to Saurik’s server (when you edit the “drivers\etc\host” file) only works if that server knows about your SHSH blobs if you generated them on a 4.0.1.
So, if you got a new iPhone 4 with factory 4.0.2 installed, wait for the iOS 4.1 jailbreak. Check the iphone dev team (http://twitter.com/iphone_dev), or others working on jailbreaks.
I had 4.0.1 on iPhone 4. Managed to JB and had Cydia save the blobs by clicking ” Make my life easier “.
Then tried to unlock and ran into some difficulties and had to restore using iTunes. Unfortunately I upgraded to 4.2.1.
How can get my blobs saved by Cydia earlier and downgrade to 4.0.1 ?
Appreciate help from the JB community. Tks