Redsn0w Improved To Fix iPhone 3GS Baseband Downgrade Issues

News

The iPhone Dev-Team has updated RedSn0w with an improved iPhone 3GS baseband downgrade method and a niche ‘DFU IPSW’ feature. As tweeted by MuscleNerd on twitter recently the bug was related to solving No Signal problem in iPhone 3GS even after a successful baseband downgrade



This version covers 3 different types of NOR chips in the iPhone 3G and 3GS (the earlier version covered only the most prevalent NOR chip). We’ve also simplified the process and added logging to help diagnose any remaining stubborn iPhones.

The revised steps are:

  1. Connect your iPhone in normal mode, then click “Jailbreak” after redsn0w identifies its model and BB version (you needn’t pre-select the IPSW anymore).
  2. Choose the “Downgrade from iPad baseband” option (you needn’t worry about de-selecting Cydia anymore).
  3. Do a controlled “slide to power off” shutdown of your phone and proceed through the normal DFU ramdisk steps.
In case of a failed downgrade, iPhone dev-team requests it’s users to help them out by posting the log from their iPhones into the comments section of the article on iPhone dev-team blog. Here are the instructions given by them
Use the “Extras->Even more->Backup” button to grab a copy of /var/mobile/Media/redsn0w_logs, then extract the log text file(s) from the zip and paste them into the comments (currently that log file is generated only during baseband downgrade runs).
Important note: iPhone 3GS manufactured in Early 2011 or late 2011 are incompatible. Trying this procedure might brick your device for good. Refrain from using this tool!