[Tutorial] Downgrade to 4.2.1 Without SHSH Blobs

[Joshrawr]

Some of you may know how to do this already, but I couldn't find anyone who had posted this, So here it is.

Firstly you need to grab the 4.2.1 Restore firmware from h t t p://appldnld.apple.c o m/iPhone4/061-9895.20101122.Cdew2/iPhone2,1_4.2.1_8C148a_Restore.ipsw

Then make sure you're in DFU mode, (Hold sleep and menu, then just menu)
Open up iTunes and it should notify you, saying the device is in recovery mode. Hold down Shift/Option key and click restore, and select the Restore firmware you just downloaded.
This should enable you to come out of DFU mode and into recovery mode, iTunes logo on the screen. You should get error 1015. Click okay and don't worry about this, exit iTunes but leave your phone in recovery mode and plugged in.
(If you get any errors, check you are in DFU mode, try using pwnage tool to help you with this. If you get a message about it not being the right build, edit your hosts file as shown below..)

If this went okay and you get error 1015 with the iTunes logo on your screen it's time for the next step.
This is where you want to edit your hosts file.
(On OS X Lion, open terminal and type "sudo nano /etc/hosts" without quotes.
On windows locate the file at "C:\Windows\System32\drivers\etc\hosts")
Add this onto the end of the hosts file.
74.208.10.249 gs.apple.com
Save.

Then, grab a custom 4.2.1 firmware from here: h t t p://forum.iphone-developers.com/hacking-jailbreaking-modding/917-ios-4-2-1-custom-ipsw-files-made-pwangetool-all-idevices.html

Next, open redsn0w, click browse, and browse for the OFFICIAL RESTORE firmware that you downloaded earlier NOT the custom one you downloaded in the step above, when you get the options, click Just enter Pwned DFU mode.
When you're ready click next and follow the instructions to enter pwned DFU mode.

When this is done, load iTunes, and accept the message about recovery mode, again Shift/Option click restore and select the CUSTOM firmware we downloaded in the step above. After this is done, it should reboot into the iOS!

[Theshawty]

and this works from 5.0?

[Theshawty]

Ive been trying to do restores much like the one you describe, but I only face errors 20 or 21, not 1015.

[Joshrawr]

and this works from 5.0?

Yeah it sure does, did it myself a few times, no SHSH blobs.
Just be sure you're restoring to the original firmware first. And then the custom firmware.

[jaldeborgh]

Hi,

I am having trouble making this work = I have a 3GS that is upgraded to 5.0 but want to get back to 4.2 or 4.3 so I can unlock the phone to use with T-Mobile.

My hosts file looks like:


##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting. Do not change this entry.
##
127.0.0.1 localhost
255.255.255.255 broadcasthost
::1 localhost
fe80::1%lo0 localhost

74.208.10.249 gs.apple.com

When I try to restore the phone (in the DFU mode) with the 4.2.1 restore firmware all I get is that the message about being the right build and Apple not allowing the restore.

Any ideas?

Thanks.

[jaldeborgh]

The iTunes error message says the phone is not eligible for the requested build. Also, I used Pwange to put the phone into the DFU mode and it confirmed I am in this mode. iTunes shows only N/A for capacity, software and serial number - if this helps.

[Theshawty]

@joshrawr

Youre either bullshitting me or being serious.

Can you make like a video guide in which you downgrade from 5 to 4.2.1/4.3.3 without SHSH blobs?


--
-Sent from my iPod touch using Tapatalk

[urmothersluvr]

i tried to downgrade and apple said it no compatible. i have a iphone 4

[urmothersluvr]

i keep gettin error 3194

[Joshrawr]

The iTunes error message says the phone is not eligible for the requested build. Also, I used Pwange to put the phone into the DFU mode and it confirmed I am in this mode. iTunes shows only N/A for capacity, software and serial number - if this helps.

Try editing your host file before you restore the official firmware and see if that helps. I do remember getting a similar message once myself.
And the capacity, software serial number problem is normal, it returns once the process is complete.