iPhone 3G Baseband Downgrade!

Good news folks.  pH, BigBoss, and EvilPenguin have created a tool to downgrade your baseband from 02.30.03 to 02.28.00.  What does this mean for you?  Well, if you upgraded (on purpose or accidentally) to 2.2.1 - then you have 2.30.03, which is not supported by yellowsn0w.

The only downside to this:  the iPhone 3G has two bootloaders:  5.8 and 5.9.  According to http://thebigboss.org, “if your iPhone was manufactured before September (2008), you are 5.8. Otherwise, you are 5.9 (that can’t be downgraded)”.

A quick and easy way to tell when your phone was manufactured is by looking at the 11 digit serial number located on the lower back of the phone.  The first two digits are the factory ID (where it came from), and the next three are date information.  The rest of the numbers are irrelevant for our purposes of downgrading

It’s digits 3-4-5 of your 11-digit serial number. The first two are the factory ID of which it was made in, and the next three are date info. I don’t know what the rest of the numbers are for.

Example:  xx832xxxxxx.  The 8 represents the year 2008.  This is the first good sign for your iPhone 3G.  The next two numbers is the week it was created.

From what I’ve come up with - if you have lower than week 36, you should be okay.  Week 36 is the end of September.  Can we get some comments to confirm this?

So to install this beautiful piece of work, you can find it on TheBigBoss repository on Cydia.  It’s called “3GBBD” (3G Baseband Downgrader).  Just download and click go - and you should be on your way!

These notes are DIRECTLY from the http://thebigboss.org post:

WARNING: This tool is NOT a toy. Just use it if you can’t use Yellowsn0w on your 2.2.1 iPhone 3G. Otherwise, DO NOT INSTALL IT JUST TO TEST! YOU HAVE BEEN WARNED!

Edit: if you have bootloader 5.9, this should not cause any harm. It should simply fail. You will then have to reboot your iPhone and should be back up to where you were before running the tool.

Big thanks to pH, EvilPenguin, and BigBoss http://thebigboss.org for this wonderful tool!