Last month, the Dev Team released a new version of RedSn0w. This version allowed iPhone 3G (and some 3GS) users to downgrade their base bands.
This was a big deal for users who had been stuck on the problematic 06.15 basebands.
Last Thursday, the Dev Team pushed out an update to the jailbreak utility that brought improvements to this feature. The downgrading process has been made simpler. Now it works on a much wider range of devices.
“Happy 4th of July! Today’s release of redsn0w 0.9.14b2 improves the iPad baseband downgrade and should cover anyone who couldn’t downgrade with 0.9.14b1. 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.”
We want to remind our readers that the 3GS warning still stands. If your iPhone 3GS was manufactured in early 2011 or later, you should not even have the 06.15.00 baseband, let alone be trying to downgrade.
Source: iDownload Blog