I'm a longtime iPhone 2G user and finally decided to upgrade to an iPhone 3GS. I bought one today off of Craigslist (32GB), thinking I could get caught up on all that's happened and get this thing unlocked (for T-Mobile). It's proven a bit more difficult and I need some help.

It is running 4.0, has Modem Firmware of 05.13.04. The previous owner was on AT&T so never saved anything on Cydia. I was hoping to be able to do a 4.1 custom firmware w/ the latest PwnageTool and then unlock it. But I'm getting the verification error ("The device isn't eligible for the requested build") and from my research, it doesn't look like I have the signatures saved on Cydia to get around that.

What are my options at this point? Thanks for any assistance you can provide.

Originally Posted by gametime10

I'm a longtime iPhone 2G user and finally decided to upgrade to an iPhone 3GS. I bought one today off of Craigslist (32GB), thinking I could get caught up on all that's happened and get this thing unlocked (for T-Mobile). It's proven a bit more difficult and I need some help.

It is running 4.0, has Modem Firmware of 05.13.04. The previous owner was on AT&T so never saved anything on Cydia. I was hoping to be able to do a 4.1 custom firmware w/ the latest PwnageTool and then unlock it. But I'm getting the verification error ("The device isn't eligible for the requested build") and from my research, it doesn't look like I have the signatures saved on Cydia to get around that.

What are my options at this point? Thanks for any assistance you can provide.

You have partly answered one of the two vital questions that every 3GS owner needs to supply before we can help. (you seem to have checked SHSH - I suggest you check again with TinyUmbrella to be sure)

The other question is: Old or new bootrom. In theory, if you had an old bootrom - you can prevent baseband update and restore to 4.2.1.
Without SHSH - there is no real solution for 4.1 (old bootrom can in theory be patched to ignore the SHSH checks, but you're not going to find an official pwnagetool bundle that can do this for you)

Fixed. I used the minimal 3GS bundle in Update #3 (blog.iphone-dev.com) to create a custom firmware w/ PwnageTool. Then used resn0w to jailbreak (w/ tethered boot after each reboot). Then used ultrasn0w to unlock (which hung at the reboot, so I had to get it into DFU mode to do another tethered jailbreak reboot), and then applied the SAM tool. Now I'm unlocked at 4.2.1 w/ all features! The only hassle is the tethered jailbreak, but hopefully that will be addressed soon. Thanks for the help.