Thread: Downgrade 4.1 (8B117) to 4.0.1 is this possible ? or device is bricked forever ???

Hi all !
My brother in law bought an iphone 4 in USA and brought it to Brazil .... it came with the 4.0.1 firmware . Another guy unlocked all features of his iphone including the carrier so it was working with any of the several Brazilian's carriers ....

Yesterday he plugged his iphone into his computer through the USB port and clicked "by mistake" into the upgrade button ;-( ..... now his iphone is running 4.1 (8B117) and no matter what I try I cannot downgrade his firmware back to 4.0.1 ;-( ... I tried different computers and so on ...

Unfortunately he didn't save his previous shsh into cyda and every time I try to restore the 4.0.1 ipw file it ends with the error 3194 ;-(

When I run the umbrella tool and click in advanced I cannot generate a shsh key file for the firmware 4.0.1 ;-( .... I can just generate to 4.1 above mentioned .... consequently the downgrade procedure never works ....

I was thinking if it's possible to generate the umbrella shsh key using a healthy iphone 4 with the firmware 4.0.1 and in the place of the ECID field put the code of the damaged iphone 4.1 .... so the key would be valid for a sucessful 4.0.1 restore into the damaged unit .... Am I right ?

Thank you very much !
--marcos

Procedures I tried:
The procedures I try are at:

HERE IS 100% WORKING DOWNGRADE FOR IPHONE 4.1 (8b117) | iPhone Network
Fix iTunes 1004, 1015 Error, and Restore iPhone 4, 3GS Successfully on iOS 4.0.1 [How to Guide] | Redmond Pie
Save iPhone 4 SHSH Blobs (ECID SHSH) on iOS 4 | Redmond Pie
Fix iTunes 1004, 1015 Error, and Restore iPhone 4, 3GS Successfully on iOS 4.0.1 [How to Guide] | Redmond Pie

Bare in mind this will not work if your shsh blobs were not saved to cydia.

Step 1: You have to download your SHSH blobs on your computer, to do so, download TinyUmbrella and connect your device to computer.

Step 2: Now, check the “Advanced Options” box. Under “Device/Version”, select theiOS which you want to downgrade to (say iOS 4.0.1 or iOS 4). Then, select “Cydia” under “Request From” and click on “Save My SHSH”. This will download your SHSH files from Saurik’s servers to your computer.

Step 3: Download your firmware for iPhone or iPod Touch.

Step 4: Put your iPhone in DFU Mode by following this steps,

• Connect your iPhone to your computer.
• Turn iPhone off.
• Start itunes.
• Hold Power and Home buttons together for 10 seconds or so.
• Release Power button but keep holding the Home button until your computer recognizes a new USB device.
• iTunes will now recognize your iPad.

Step 5: Run TinyUmbrella and click the “Display SHSHs” button to make sure your SHSH blobs were downloaded to your computer. Once done, click “Start TSS Server”.

Step 6: Now, You will have to restore your iPhone to iOS 4.0.1 by Clicking on the iPhone icon on the left sidebar of iTunes then hold left “alt” button (“Shift” button on Windows) on the keyboard and then click on “Restore” then release the alt button, Now Select the iOS 4.0.1 ipsw file you have already downloaded in Step 1 and Let iTunes do some automated Steps.

Step 7: iTunes might give you error messages (error 1011, 1013, and 1015). Just ignore the.

Step 8: Now, you will need to get out from Recovery mode, just hit “Kick Device Out of Recovery” in TinyUmbrella.