Downgrading to an Unknown Firmware

[lorax3]

Friend of mine had to restore and ended up updating to 4.3.4. Her phone was previously Jailbroken but she cannot recall the firmware that she was on prior to the restore. (I'm going to guess and say it was 4.3 or 4.3.1)

Now Cydia seems to store SHSH Blobs for a firmware even if you are not on that current firmware or not. E.g. Cydia will store blobs for 4.3.1 even if your iPhone is 4.1


She is using windows, so I'm going to guess if I can find where Windows stores its iTunes backups I will be able to tell her previous firmware.

Does it really matter which FW I downgrade to? Seems my only considerations would be official iOS features or JB software that only works with certain FW versions.

I'll restore her phone on my mac, but I recall reading I would need to point to which blobs I wanted to use in TU?

I was originally under the impression I could just edit my hosts file and DL a pre-cooked FW.

 

[mutchy126]

As long as the SHSH Blobs were saved for the Firmware she wants to Downgrade to, It should all work.

 

[Abs_p]

Downgrade to 4.2.1/4.3.3 as per your wish .. I prefer 4.2.1 coz my phone runs fastest and has best battery life on it..

Do this download tinyumbrella. Click on save shsh.
It will download the shsh for the firmwares Cydia has shsh of..

If u wanna downgrade to 4.3.3 fireup TSS server on tiny umbrella .. ( make sure there are blobs on it.. Shift restore in iTunes .. It's ctrl restore In Mac if I remember correctly..
After a while it will give u 1013.
Download fixrecovery for Mac from tiny umbrella blog.
Run it..
You are done.
Run redsn0w to jb.