Guys,

A friend let an iPhone 3GS stuck on the startup (it powers on, shows the apple logo and then shows the little circle and freezes). He doesn't know the firmware but believes it is 3 low. It was jailbroken and unlocked.

I've used usbview and got the ECID, then TinyUmbrella, checked and there are no SHSH saved.

I believe I'll won't be able to restore any 3.xx firmware as there will be no authentication, correct?

The only way to restore it would be to the latest and I would have to stay with a thethered jailbreak to preserve the unlock capability, right?

Thank you in advance for any advise.

One more thing, through USBVIEW just checke iboot = 359.3 Does that mean it is the old bootrom?

359.3 does indicate this is an old bootrom 3GS, meaning you should be able to untether even a 5.x jailbreak. You are correct that without an SHSH, your only real choice is to upgrade to 5.0.1. That said, you can attempt to use iFaith to get blobs from the currently running version.

Thanks! Didn't find a way to update to 5.0 without updating the baseband to keep the unlock capability. Do you know if it is possible?

UPDATE: Guys, managed to successfully upgrade to 5.0.1 while keeping the baseband (04.26.08). From Cydia, I see now SHSH for 4.1.

Installed Ultrasn0w but it keeps with No Service with my carrier sim card. From DevTeam I see that Ultrasn0w should be compatible with iOS 5, but doesn't work for me. Before downgrading to firmware 4.1, I'd like to check with you guys if I'm not doing anything wrong.

an additional note, when Cydia asks for upgrading (Core Utilities / bin) it gets a Hash Sum mismatch error. Does this have anything to do with the Ultrasn0w?

ultrasn0w on iOS 5.0.1 requires you to use the patched commcenter by wortel (the 5.0.1 commcenter blocks ultrasn0w, but you can use a patched version of the commcenter from 5.0.0 to unlock on 5.0.1), you can find instructions on how to patch yours by searching the forums. Without it, you just get the searching/no service issue.

I don't believe the Cydia error is related, but I'm not 100% certain. Get the commcenter issue worked out and see if that helps first.