Cannot Upgrade!

[Tokyo]

Been trying for a few days but no prevail. Trying to upgrade an iPhone 3G on 3.1.2 with a 5.11.07 Baseband to 4.1 (with Snowbr33ze custom firmware). (Windows XP OS)

Every time I try to put it in DFU mode and restore I get a 16XX error (every time) and if I use iReb and it's green screen I get error 21. I also get an error if I use the latest version of Redsn0w to put it in DFU. I'm running the lastest version of iTunes. Any ideas t approach this, I've tried each method a million times but can't think of anymore solutions. Thanks

[DevouredDreams]

do you have your shsh for 4.1 if not you can take it to custom firmware 4.2.1 theres some 4.2.1 custom firmwares in the news section posted

[Tokyo]

I forgot to mention, I downloaded that firmware but got the same errors. Custom firmware isn't working in general, I also tried it on two computers (Both Windows XP)

[i.Annie]

But do you have SHSHs for 4.1?

[Tokyo]

I'm assuming I don't since I don't know what it is, how do I go about getting it?

[i.Annie]

Some people have them saved and don't even know it. But you should check. If you didn't have them before last year, you won't have them now. You can still check with TinyUmbrella from thefirmwareumbrella.blogspot.com

If you don't have it, you should find a custom 4.2.1 firmware that does NOT include the iPad baseband upgrade via Google to restore to if you are still interested in upgrading.

Btw, you probably used sn0wbreeze 2.1 which does not work well if at all with the iPhone 3G. If you do find you have SHHs for 4.1 you should find sn0wbreeze 2.0.2 to create a 4.1 custom firmware to use with.

[Tokyo]

Ok so turns out I did in fact have 4.1 SHSH, but regardless with the server cut on it still got the same results.

So I just upgraded to 4.0 (5.13.04) BB which is still unlock-able, so now I will try Sn0wbreeze 2.0.2 to make a custom firmware and see if that changes anything. I'll keep you updated, thanks i.Annie!