Can I Downgrade an Unlocked 3.1.2 to 2.2.1

[spitboy2000]

3.1.2 on my 3G has caused horrible Wifi problems which seem to be quite common. It's running 5.11 baseband....

Can I downgrade my OS? Hopefully that will solve the Wifi troubles...

 

[dhlizard]

3.1.2 on my 3G has caused horrible Wifi problems which seem to be quite common. It's running 5.11 baseband....

Can I downgrade my OS? Hopefully that will solve the Wifi troubles...

The firmware on a 3G can be upgraded and downgraded to any firmware version, but you cannot downgrade the baseband unless you have 5.08 bootloader. Only about 10% of the very first 3G phones came with that bootloader.

You must be jailbroken to use FuzzyBand from Cydia to check and see if your baseband is downgradeable.

As far as the firmware, just download the desired version and use option + click (Mac) or shift + click (PC) to point iTunes at the desired version.

If you downgrade to 2.2.1 you may have an issue with the firmware not being compatable with the 5.11.xx baseband.

Why not just go to 3.0 or 3.0.1 ??

Or, if you jailbroke your phone with Blackra1n, restore it and JB with Pwnage Tool and you won't have Wifi issues. Always choose set up as new.