TangoEight Posted January 29, 2011 Share Posted January 29, 2011 Apple, in all of their infinite wisdom, have decided to make it hard to downgrade iOS versions. This makes things awkward when you need to use an older version for jailbreaking or any other reasons that I can't think of. It is possible to downgrade by having SHSH blobs on Saurik's server, but you probably don't and that's why you're reading this guide. This method works by editing some of the files in the .ipsw file that contains the firmware to trick Apple's verification system into thinking that you are restoring to the current firmware. 7zip can be found here: http://www.7-zip.org/ iPodRobot plist Editor is somewhere over here: http://download.cnet.com/Plist-Editor/3000-18551_4-10909598.html You can find .ipsw files here: http://www.felixbruns.de/iPod/firmware/ Note: This has only been tested on an iPod Touch 2G because that is all I have. This does not work for 3.1.3 (for me anyway). Your mileage may vary. Other Note:I did not think of this, I found it after updating to 4.1, not liking it and googling for a way to fix it. Even more notes: Click the images to enlarge. 1. Download the ipsw file you will be restoring to an put it somewhere on your computer. 2. Make all file extensions visible. Press the Alt key and select Tools>Folder Options... Got to the View tab and uncheck Hide extensions for known file types. Apply and close. 3.Make a new folder and copy the .ipsw into it so you have two copies with the same filename. 4. Rename the file to a .zip. Rename it changing only the extension to .zip. Because you are changing the file type you will get a warning, click Yes. 5. Open the .zip and copy the BuildManifest.plist and Restore.plist files into the folder with your .ipsw file. 6. open the .plist files with iPodRobot. Find and replace the original build number with the build number of the latest firmware for your device. It should appear twice or three times in BuildManifest.plist and once in Restore.plist. The build number is in the file name and next to the device name on the list here. The file name should be in this format: ipod2,1_4.0_8A293_Restore.ipsw "device name"_"version number"_"build number"_Restore.ipsw 7. Create the modified firmware. Delete the BuildManifest.plist and Restore.plist files from the .zip file and copy in your modified .plist files in their place. Rename the zip file into an .ipsw file like in step 4. 8. Finishing. If you prefer to hide extensions repeat step 2, checking the box. Open iTunes and connect your iDevice shift click the Restore button and select your modified firmware. From here, continue the restore as normal. If you get a 1394 error, you are using the wrong build number, try older build numbers, 8B117 seems to work on iPod Touch 2G (as of January 2011). T8 Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/ Share on other sites More sharing options...
UN1X Posted February 2, 2011 Share Posted February 2, 2011 Thanks alot for posting a link to this topic, I have a 4G iPod Touch and ill let you know how it goes. I will also post if jailbreaking works using this method. Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593657808 Share on other sites More sharing options...
UN1X Posted February 2, 2011 Share Posted February 2, 2011 I tried using the method but I keep getting a 3194 error. I have 4.2.1 on a 4G iTouch and I'm trying to get down to 4.1. I have edited the firmware, but it doesn't seem to be tricking the apple servers. Do I have to edit the file name to match the new firmware as well? I guess it's no luck for 4G 4.2.1ers as of now? Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593658094 Share on other sites More sharing options...
TangoEight Posted February 3, 2011 Author Share Posted February 3, 2011 I tried using the method but I keep getting a 3194 error. I have 4.2.1 on a 4G iTouch and I'm trying to get down to 4.1. I have edited the firmware, but it doesn't seem to be tricking the apple servers. Do I have to edit the file name to match the new firmware as well? I guess it's no luck for 4G 4.2.1ers as of now? 3194 is the one I meant at the end of the first post. I think it means the build number you used is for an older firmware which they don't want you using anymore or its for a different device. The latest build number for your iPod (4G) is 8C148. The example I used was for a 2G. T8 Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593659954 Share on other sites More sharing options...
UN1X Posted February 3, 2011 Share Posted February 3, 2011 3194 is the one I meant at the end of the first post. I think it means the build number you used is for an older firmware which they don't want you using anymore or its for a different device. The latest build number for your iPod (4G) is 8C148. The example I used was for a 2G. T8 I used 8C148. It gave me 3194. I've even tried doing it with tinyumbrella in a separate tutorial. No success. Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593660052 Share on other sites More sharing options...
Dinggus Posted February 3, 2011 Share Posted February 3, 2011 I tried using the method but I keep getting a 3194 error. I have 4.2.1 on a 4G iTouch and I'm trying to get down to 4.1. I have edited the firmware, but it doesn't seem to be tricking the apple servers. Do I have to edit the file name to match the new firmware as well? I guess it's no luck for 4G 4.2.1ers as of now? Try TinyUmbrella, it'll "kill" the process to connecting to Apple Servers. Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593660072 Share on other sites More sharing options...
TangoEight Posted February 3, 2011 Author Share Posted February 3, 2011 The build number for 4.1 worked for me but it probably won't work for restoring to 4.1. I don't know what else to suggest. Tiny umbrella won't work by itself because you need apple to verify the restore, iTunes needs to receive the "OK" message from apple or it will give you the 3194 error. T8 Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593660726 Share on other sites More sharing options...
TangoEight Posted February 3, 2011 Author Share Posted February 3, 2011 I tried using the method but I keep getting a 3194 error. I have 4.2.1 on a 4G iTouch and I'm trying to get down to 4.1. I have edited the firmware, but it doesn't seem to be tricking the apple servers. Do I have to edit the file name to match the new firmware as well? I guess it's no luck for 4G 4.2.1ers as of now? Just thought, did you edit the restore.plist file too, I didn't include a picture for that one and didn't make it that clear. I had a go at doing it for your ipod, will link to the file when it uploads so you can test it, these retina graphics make it a huge file :/ T8 Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593662834 Share on other sites More sharing options...
Tech Star Posted February 3, 2011 Share Posted February 3, 2011 I might try this. I am on 4.0 with my iPod Touch 2G and I just hate the battery life now. I have wanted to go back to 3.1.3. Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593662850 Share on other sites More sharing options...
Brandon H Supervisor Posted February 3, 2011 Supervisor Share Posted February 3, 2011 it seems that if you buy an ipod 4g that already has 4.2.1 on it there is no way to downgrade it to 4.1, not really sure what they changed but it can not be done if you've upgraded to 4.2.1 you can downgrade back to 4.1 but not if the ipod's only had 4.2.1 for whatever reason Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593662878 Share on other sites More sharing options...
Brandon H Supervisor Posted February 3, 2011 Supervisor Share Posted February 3, 2011 Just thought, did you edit the restore.plist file too, I didn't include a picture for that one and didn't make it that clear. I had a go at doing it for your ipod, will link to the file when it uploads so you can test it, these retina graphics make it a huge file :/ T8 can you send me a link too, i'm trying to get my friends new ipod downgraded so he can jailbreak it, if it doesn't work i guess we'll just have to wait till greenpois0n's 4.2.1 jailbreak is released :/ Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593663016 Share on other sites More sharing options...
TangoEight Posted February 3, 2011 Author Share Posted February 3, 2011 I tried using the method but I keep getting a 3194 error. I have 4.2.1 on a 4G iTouch and I'm trying to get down to 4.1. I have edited the firmware, but it doesn't seem to be tricking the apple servers. Do I have to edit the file name to match the new firmware as well? I guess it's no luck for 4G 4.2.1ers as of now? The whole ipsw isn't going anywhere on my connection :no: but here are the files you will need to move into the ipsw replacing the existing copies. BuildManifest.plist Restore.plist iPod touch 4g restoring down to 4.1 ONLY T8 Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593663298 Share on other sites More sharing options...
Brandon H Supervisor Posted February 3, 2011 Supervisor Share Posted February 3, 2011 The whole ipsw isn't going anywhere on my connection :no: but here are the files you will need to move into the ipsw replacing the existing copies. BuildManifest.plist Restore.plist iPod touch 4g restoring down to 4.1 ONLY T8 you put the same link for both files Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593663376 Share on other sites More sharing options...
TangoEight Posted February 3, 2011 Author Share Posted February 3, 2011 you put the same link for both files Sorry about that. Restore.plist http://www.box.net/shared/koxtvf5a68 T8 Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593663446 Share on other sites More sharing options...
Brandon H Supervisor Posted February 4, 2011 Supervisor Share Posted February 4, 2011 sadly i still get the same error :( Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593664044 Share on other sites More sharing options...
TangoEight Posted February 4, 2011 Author Share Posted February 4, 2011 Apple might have increased security for newer iPods. Not sure if there is any other way to restore down other than with SHSH blobs but I think you need jailbreak for them. Will post if I find anything. T8 Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593664436 Share on other sites More sharing options...
TangoEight Posted February 4, 2011 Author Share Posted February 4, 2011 Got some good news for you, Greenpois0n has been released for iOS 4.2.1 http://lifehacker.com/5752219/greenpois0n-brings-a-long+awaited-untethered-jailbreak-to-ios-421 Tried to look in the .dmg files in the .ipsw but they're encrypted :( T8 Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593667162 Share on other sites More sharing options...
Brandon H Supervisor Posted February 5, 2011 Supervisor Share Posted February 5, 2011 awesome, just in time to give the ipod back to my friend tomorrow that was the whole reason for trying to downgrade it was so i could jailbreak it crap, just realized it's only released for osx right now :/ if i'm lucky i'll be able to log onto one of the macs at school tomorrow and do it from there Link to comment https://www.neowin.net/forum/topic/972006-restore-idevices-to-older-firmware/#findComment-593667810 Share on other sites More sharing options...
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