[Tutorial] Downgrade any Iphone/IpodTouch from 4.2.1

[SoftMango]

Ok guys I just found this glitch within iREB to downgrade your ipod touch or iphone. I was trying to load up custom firmware to my ipod touch 2nd gen and I got stuck with a black screen, and I start to fiddle with itunes and ireb. Downgraded my 2nd generation ipod touch from 4.2.1 to 2.1.1 (the very first firmware for this model). Below ive put the instructions on how I did this. (Ive only tested this on my ipod, but it should work on anything that iREB can support.

iREB is not available for Mac users as of yet, will update if changes occur.

1)First you will need to change your hosts

Navigate to C:\Windows\System32\drivers\etc\ and locate “hosts” file.
Open this “hosts” file in Notepad and add this "74.208.105.171 gs.apple.com at the bottom of the note".

Credits to Komentra for the reply

2) Download iREB V4.0.x/4.1:

http://ih8sn0w.com/index.php/products/view/ireb.snow

3) Download the ipod firmware that you wish to downgrade to. (unless a new version of iREB is released, anything above 4.2.1 wont work. (I KNOW IT SAYS V4.0.x/4.1 BUT THATS PART OF THE GLITCH)

Download Firmware Here: http://www.felixbruns.de/iPod/firmware/

4) Plug in your iPod/iPhone and load up iREB.

5) Select your device from the menu.

6) Wait for iREB to put your device into its SPECIAL dfu mode. (not the normal one)

7) Now, open iTunes and wait for your iPod to come up, now heres where I was experimenting.

8) put your ipod into dfu mode (I know what your thinking "oh this guy is an idiot, he doesnt know what hes doing" well this where stuff gets interesting. You cant see whats going on the ipod but wait for those USB chimes so you will know what to press and when. - Hold both the power and home button at the same time untill you hear a usb sound from your computer. When that sound comes let go of the power button and keep holding the home button and wait for the second usb sound. -

9) Hold shift and click restore in itunes and find your old firmware (ie. 2.1.1)

10) AND YOUR DONE!

I know what your thinking again (im a mind reader) WHY WOULD YOU WANNA DO THIS? well for me, iOS 4.2.1 is a load of bull for me, it goes way too slow and jailbreaking it makes it even worse. and pretty much all I do on my ipod is listen to music and nothin else, no lies. Seriously, and if you need to downgrade for a practical reason, then why not.

This should work on any OLD firmware that is older then your current one. (again ive only tested this on 4.2.1)

Hope this helped.
SoftMango out.

Update For 1st & 2nd Generation devices

3.1.3 cannot be downgraded with this method. Here are the steps to solving this problem:

Download the following files:

Sn0wBreeze: http://www.mediafire.com/?2wt8v7yw1jlpnoc

Firmware 3.1.3: http://www.felixbruns.de/iPod/firmware/

1) Plug in your ipod touch/iphone

2) open sn0wbreeze and say ok to the release

3) go to the next step and browse the firmware (3.1.3)

4) On the next step click build ipsw

5) let the program create the custom firmware.

6) go to the next step and instructions will pop up showing you how to put your ipod into dfu mode.

7) follow the on screen steps and then your ipod will be put into a pwned state.

8) restore your ipod in itunes with the custom firmware that was made earlier.

9) Your Done!

I will be continually updating this thread when new stuff is out.

 

[Komentra]

Great post. This worked just fine for downgrading my iPod Touch 4g from 4.2.1 to 4.1. You probably should mention that the person needs to edit their hosts file or else it will fail when verifying the restore with iTunes.

Navigate to C:\Windows\System32\drivers\etc\ and locate “hosts” file.
Open this “hosts” file in Notepad and add this "74.208.105.171 gs.apple.com".

I would of added Mac instructions but unfortunately iReb isn't available for Mac yet.

 

[SoftMango]

Oh yeah, I changed the host a while back, totally forgot.

Thanks!

 

[lambchucks40]

Can you clarify step #8 please.

 

[SoftMango]

Sure, so basically after you've done step 6, your ipod or iphone should have a black screen. This is because it is in iREB's special dfu mode. After that, you must put it into dfu mode again manually. Hold both the power and home button at the same time untill you hear a usb sound from your computer. When that sound comes let go of the power button and keep holding the home button and wait for the second usb sound. Now your done step 8.

 

[NathanA]

This will NOT work for "any iPhone/iPod touch." This needs to be made clear for anybody who thinks this is a one-size-fits-all solution for everybody.

Apple cryptographically "signs" firmware releases these days. This happens during the restore process, and unless Apple signs off on the restore, you'll get an error message. Even if you could bypass the error message, without the signatures specific to your device for that iOS version, your device would never boot up.

Apple prevents downgrades by refusing to sign anything but the latest version of software. This is where Saurik's SHSH collector and TSS server come into play, for those that take advantage of his services.

The reason it worked for YOU is because you have a second-generation iPod touch and you were downgrading to something less than 4.0. Apple didn't start using device-specific (ECID-based) SHSHs until 3.x on iPhone 3GS and iPod Touch 3rd-gen, and 4.x on all other devices that support 4.x (including iPhone 3G and iPod Touch 2nd-gen). So, unless you are collecting your SHSHs for each Apple software release, if you are on 4.2.1 on your iPod touch, you would be able to downgrade to 2.1.1 like you did, but you would not be able to downgrade to 4.1 or 4.0.

Also, you didn't technically need iREB for this. All you used iREB for was to get the iPod into DFU mode. You can do that yourself, manually, using the power and home buttons...instructions for doing so are in abundance on-line.

If you have an iPhone 3GS, iPhone 4, iPod touch 3rd-gen, or iPod touch 4th-gen, you can't downgrade to any release without the corresponding SHSH for your device. Period.

-- Nathan

 

[Komentra]

This will NOT work for "any iPhone/iPod touch." This needs to be made clear for anybody who thinks this is a one-size-fits-all solution for everybody.

Apple cryptographically "signs" firmware releases these days. This happens during the restore process, and unless Apple signs off on the restore, you'll get an error message. Even if you could bypass the error message, without the signatures specific to your device for that iOS version, your device would never boot up.

Apple prevents downgrades by refusing to sign anything but the latest version of software. This is where Saurik's SHSH collector and TSS server come into play, for those that take advantage of his services.

The reason it worked for YOU is because you have a second-generation iPod touch and you were downgrading to something less than 4.0. Apple didn't start using device-specific (ECID-based) SHSHs until 3.x on iPhone 3GS and iPod Touch 3rd-gen, and 4.x on all other devices that support 4.x (including iPhone 3G and iPod Touch 2nd-gen). So, unless you are collecting your SHSHs for each Apple software release, if you are on 4.2.1 on your iPod touch, you would be able to downgrade to 2.1.1 like you did, but you would not be able to downgrade to 4.1 or 4.0.

Also, you didn't technically need iREB for this. All you used iREB for was to get the iPod into DFU mode. You can do that yourself, manually, using the power and home buttons...instructions for doing so are in abundance on-line.

If you have an iPhone 3GS, iPhone 4, iPod touch 3rd-gen, or iPod touch 4th-gen, you can't downgrade to any release without the corresponding SHSH for your device. Period.

-- Nathan

You sure about that? It worked fine for me when going from 4.2.1 to 4.1 on my touch 4g. I did get the error message you speak of but after editing the hosts file I no longer got that error and it went right along with the restore.

 

[Intell]

You sure about that? It worked fine for me when going from 4.2.1 to 4.1 on my touch 4g. I did get the error message you speak of but after editing the hosts file I no longer got that error and it went right along with the restore.

He's very sure, as am I. When you edited the hosts file, you pointed iTunes to the Cydia SHSH cache server where your 4.1 blobs are stored. There is no way to downgrade a iPhone 3Gs, iPhone 4, iPod Touch 3G, or an iPod Touch 4G without these blobs. You can downgrade an iPhone 3G and iPod Touch 2G and 8Gb 3G using this method. Because they use "soft" SHSH blobs which can be overridden.

 

[SoftMango]

sorry about that guys. I just thought that since it worked for me I'd get it out there. I just figured out about that ssh blobs stuff and so for me the easier way to do it was using sn0wbreeze. After the fact that I did a little more research which o shoudve have done earlier before
making this thread. Well at least I helped 1 guy just joined too double thumbs up :$

 

[Komentra]

He's very sure, as am I. When you edited the hosts file, you pointed iTunes to the Cydia SHSH cache server where your 4.1 blobs are stored. There is no way to downgrade a iPhone 3Gs, iPhone 4, iPod Touch 3G, or an iPod Touch 4G without these blobs. You can downgrade an iPhone 3G and iPod Touch 2G and 8Gb 3G using this method. Because they use "soft" SHSH blobs which can be overridden.

Ah, okay. I must of been misinformed. I was thinking by editing the hosts file that just denied the apple server's access. I had no idea it connected to Cydia.

 

[shademan64]

i get error 1600

 

[hansgmuny]

downgrade advice

He's very sure, as am I. When you edited the hosts file, you pointed iTunes to the Cydia SHSH cache server where your 4.1 blobs are stored. There is no way to downgrade a iPhone 3Gs, iPhone 4, iPod Touch 3G, or an iPod Touch 4G without these blobs. You can downgrade an iPhone 3G and iPod Touch 2G and 8Gb 3G using this method. Because they use "soft" SHSH blobs which can be overridden.

taking this quote into consideration, can i just use the latest release of redsnow, following instructions on how to use it, to downgrade my jailbroken, unlocked 3G 8gb iOS 4.2.1 BB 6.15.00 to iOS 3.1.3?
if so do i have to downgrade the BB also? should i downgrade the BB also?
my iphone runs so slow now i have moments where destructive tendencies are hard to ignore. i basically use my phone as a phone. not interested in oodles of apps, some would be nice but i can do without to tell the truth. Also 4.2.1 was the original FW on the phone.
i apologize if my verbiage is incorrect.
a big thank you in advance to any and all who take the time to read this!!