Hi,
Here I'll be describing my 'adventure' to successfully unlock iPhone 3GS (new bootloader) without SHSH blobs.
If you check my previous Blog entry you'll see how hard it was for me to downgrade. Well, unlocking wasn't easier!
The key points to unlock this phone are:
- Upgrade to iPad baseband (if you have an incompatible baseband)
- Restore to stock iOS 4.1, then to custom iOS 4.1
- If need install iPad baseband again!
Upgrading to iPad baseband was pretty easy at first but there are a few thing you should have into consideration BEFORE doing this:
- Upgrading doesn't allow you to restore your previous baseband (so far there is no such tool but there might be in the future)
- Using iPad baseband might make your GPS useless. (not sure if this was ever fixed or if it will be)
- Installing a stock IPSW after this might render you iPad baseband useless, if so reinstall iPad baseband.
Ugrading to iPad baseband can be done using either redsn0w or sn0wbreeze.
What I did was what is think is the safest:
- Restore to stock iOS 4.1 (not 4.3.3) - see my previous post
- Saved my SHSH blobs using TinyUmbrella
- Enter normal DFU mode and restore to costume iOS 4.1 (not 4.3.3)
- After all is done upgrade to iPad baseband (using latest Redsn0w)
- Use ultrasn0w (current version 1.2.4) to unlock you device, from cydia.
Comment if you have any questions! ;)

