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iPhone Downgrading 3GS to 4.1 without jailbreak

G

guspasho

macrumors regular
Original poster
Apr 13, 2011
152
15
I want to downgrade my 3GS to iOS 4.1 without jail breaking it. Apple is still signing 4.1 for the 3GS and I have blobs saved from Tiny Umbrella. The 3GS is currently on 5.0.1. I've been putting it in recovery mode, running TSS server from TU, and selecting the 4.1 ipsw using option+restore in iTunes, but every time I get a different error message.

Is it even possible to downgrade a non-jailbroken device, with blobs? I cannot find any clear instructions on how to do it anywhere. Thanks!
 
I haven't tried myself, but I'd imagine it shouldn't be an issue. Though down grading to a lower major iOS would be a pain if not signed, but in this case it is. What are the errors your getting? You say they vary?
 
If 4.1 is being signed, you should be able to just use iTunes. Don't use tss server and make sure your host files point to apple's servers, not Cydia servers. Download the official 4.1 firmware file. Once you've taken care of this checklist, plug your phone into the computer, enter DFU mode, open up iTunes and shift click restore. Then manually choose the 4.1 firmware file you just downloaded. If apple is signing it, it should restore no problem.

What errors are you getting. Maybe you're having a USB cable/port issue too.
 
BumpyFlatline said:
If 4.1 is being signed, you should be able to just use iTunes. Don't use tss server and make sure your host files point to apple's servers, not Cydia servers. Download the official 4.1 firmware file. Once you've taken care of this checklist, plug your phone into the computer, enter DFU mode, open up iTunes and shift click restore. Then manually choose the 4.1 firmware file you just downloaded. If apple is signing it, it should restore no problem.

What errors are you getting. Maybe you're having a USB cable/port issue too.
Click to expand...

Was about to say exactly this. Just shift+restore - no TU needed if Apple is still sighing the firmware.

Also, being jailbroken has nothing to do with restoring at all, so don't worry about whether you are or are not jailbroken. The process is identical anyway.
 
kalirob99 said:
I haven't tried myself, but I'd imagine it shouldn't be an issue. Though down grading to a lower major iOS would be a pain if not signed, but in this case it is. What are the errors your getting? You say they vary?
Click to expand...

I'm getting errors 20, 1015, and 3014 most frequently. Sometimes a few others, 1016 among them I think.

----------
BumpyFlatline said:
If 4.1 is being signed, you should be able to just use iTunes. Don't use tss server and make sure your host files point to apple's servers, not Cydia servers. Download the official 4.1 firmware file. Once you've taken care of this checklist, plug your phone into the computer, enter DFU mode, open up iTunes and shift click restore. Then manually choose the 4.1 firmware file you just downloaded. If apple is signing it, it should restore no problem.

What errors are you getting. Maybe you're having a USB cable/port issue too.
Click to expand...

I've done all this. Maybe I'm not using the official IPSW? Where can I find the official one.
 
Applejuiced said:
You have the iPad bb installed?
Click to expand...

I was just thinking that.
If not, I wonder if your using a custom host file (you edited/added entries). It can be testy over that when you restore. And no need to use TU, it's still signed. >_>b So you just need the ips and iTunes.
 
Applejuiced said:
You have the iPad bb installed?
Click to expand...

I don't know. I don't know what that means. I have attached a few iPads to this system, and restore them regularly through iTunes, an iPad 1 (GSM) and an iPad 2 (CDMA), neither have an active 3G plan though.

----------
kalirob99 said:
I was just thinking that.
If not, I wonder if your using a custom host file (you edited/added entries). It can be testy over that when you restore. And no need to use TU, it's still signed. >_>b So you just need the ips and iTunes.
Click to expand...

Thank you! My hosts file has been edited! I'm going to try a clean system and see if this gets easier. In the future I want to restore to no-longer-signed versions of iOS, such as 5.1.1 after 6 comes out, and I was trying to figure out that process as well. I still need to figure it out.
 
ZCherub said:
Go to Settings > General > About, and tell us what the modem firmware section says.
Click to expand...

So an update. I managed to downgrade it to 4.1, somehow. iTunes threw up an error message saying it didn't like it (I don't remember the specific message, I think something about not being eligible for an update?), and I wanted to repeat the feat anyway, so I updated to 5.1.1. Currently, with 5.1.1 (9B206), the modem firmware section says "05.16.05".

And trying to downgrade on a clean MacBook Pro gets me error 20 every time. There is no third party software installed, iTunes and OSX are up-to-date (10.6.3 and 10.7.4 respectively), all updates applied.

My steps are as follows:

1) Connect the 3GS
2) Option+Restore in iTunes, select the restore file that utahman130 linked to earlier in this topic
3) Open, Restore, then iTunes produces the error "The iPhone "iPhone 3GS" couldn't be restored. An unknown error occurred (20)." and the phone is stuck in recovery mode with the Connect to iTunes image on the screen, the only way I know to recover from that is to restore using 5.1.1.

EDIT: Re-reading the steps above, I noticed I didn't put the iPhone in DFU mode. After doing this I still get the error message "The iPhone "iPhone" could not be restored. An unknown error occurred (1015)."

Steps are as follows:
1) Connect the 3GS to iTunes
2) Turn the phone off
3) Press and hold power and home on the phone for 10 seconds, release power and hold home for another 10 seconds, to place phone in DFU mode
4) Option+restore in iTunes, select the 4.1 restore
5) iTunes produces the error 1015 and the phone is in (non-DFU) recovery mode.
 
Last edited:
Error 1015
This error is common when downgrading iPhones and 3G-enabled iPads. The problem occurs when the device's baseband has a higher version number than the baseband in the firmware you restored to. Just set auto-boot true in iRecovery or use iREB/TinyUmbrella/RecBoot.1 In case this is not working use Pwnage Tool to create a custom firmware WITHOUT the iPad baseband, put your device in pwned DFU mode and restore via iTunes.


Just make a cudtom firmware, go into pwn-DFU and shif/alt restore in itunes
 
So you can GUARANTEE that they are signing it and i can just save shsh with tinyumbrella? I am able to return it in 7 days. I dont have the iPhone yet. I will soon. I just want to make sure
 
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