Downgrade Baseband 02.x.x to 1.59.00

gabr · Oct 9, 2010

Hey guys,

a VERY interesting thing caught my attention while reading about the JB and the Unlock... it was mentioned on one of the websites that you can downgrade your BB using TinyUmbrella from 2.x to 1.59.00 which then can be unlocked using the Ultrasnow unlock!
these are the steps:

Close TinyUmbrella (if open)

Close iTunes (if open)

Remove ALL lines in your hosts file that contain gs.apple.com

Windows: Start -> cmd -> ipconfig /flushdns

Mac: Terminal -> dscacheutil -flushcache

Start iTunes

Restore (NOT UPDATE) Stock 4.0.2 iPhone 4 - 4.0.2 Download

Note that this will only work while Apple is signing 4.0.2 SHSH requests. This is due to the way Apple now updates/restores Baseband Firmware for the iPhone 4 different from the way it did to prior devices. Lucky us...

now concerning the case that i bought the iphone already with FW4.1 on and BB 02.10.04 ... is this procedure applicable?? can i downgrade my bb even if i do not have any SHSH blobs saved or whatever?? and can anyone give me any sources to read about SHSH and understand what it is and its use??

thanks