need help on downgrading baseband 6.15

[jayson1040]

does anyone know how to downgrade on baseband 6.15 on iphone 3g, ever since i ungraded to 6.15 to unlock the iphone, it's not the same anymore, reason is, can't restore in itunes and iphone doesn't boot-up sometimes. please help!!!!

[805 93003]

Only a very old iPhone 3g with the original bootloader 5.8 can have the baseband downgraded. There is no other iPhone that can have the baseband downgraded. Use Cydia to install Fuzzyband software and see if you have the 5.8 bootloader, it is very rare. If you have 5.9 bootloader no downgrading is possible.

To get your iPhone 3g working better I think you can restore to 3.1.3 and use Tiny Umbrella to kick out of recovery mode or whatever error you may encounter. Also you could make a custom firmware with Pwnage Tool Mac or Sn0wbreeze PC and install, if you have the SHSH for System 4 files, except for 4.2.1 because Apple is still signing 4.2.1 for 3g.

[Cer0]

You do not need to make 2 threads on the same thing. This one is closed. PLease use the one in the better section.

how to downgrade from baseband 6.15