I am very new to the whole jailbroken and unlocked iPhone scene, so I would like to get the most current information before I attempt this.
The facts: This is a 3G already unlocked and running on Tmobile. I bought the phone in this condition, but blackra1n is installed, so I guess it was done with that. It is currently running 3.1.2(7D11), with modem firmware 5.11.07.
I want to upgrade to some version of iOS4, but am a bit worried about losing the unlock, as that would be a disaster.
Any tips on how I should go about this, and/or any pitfalls I may encounter?

Thanks in advance.

Originally Posted by alfadoc

I am very new to the whole jailbroken and unlocked iPhone scene, so I would like to get the most current information before I attempt this.
The facts: This is a 3G already unlocked and running on Tmobile. I bought the phone in this condition, but blackra1n is installed, so I guess it was done with that. It is currently running 3.1.2(7D11), with modem firmware 5.11.07.
I want to upgrade to some version of iOS4, but am a bit worried about losing the unlock, as that would be a disaster.
Any tips on how I should go about this, and/or any pitfalls I may encounter?.

Two vital things you need to confirm:

Do you have access to a Mac? Preventing baseband update can only be done safely with Pwnagetool
If you don't want to go to 4.2.1, then you need to check if there are any SHSH saved for the device (TinyUmbrella will do this).

Yes I have a Mac, and I downloaded Pwnagetool 4.1.3. Am I right to assume this will update the phone to iOS 4.1.3?
As for the SHSH, I opened Cydia, and at the top in green it says "SHSH: iOS 4.0, 4.0.1, 4.0.2,4.1, 4.2.1". Is this what you meant?

Originally Posted by alfadoc

Yes I have a Mac, and I downloaded Pwnagetool 4.1.3. Am I right to assume this will update the phone to iOS 4.1.3?

No, Pwnagetool 4.1.3 is designed to support iOS 4.2.1 and iOS 4.1

Originally Posted by alfadoc

As for the SHSH, I opened Cydia, and at the top in green it says "SHSH: iOS 4.0, 4.0.1, 4.0.2,4.1, 4.2.1". Is this what you meant?

This is good news - you have options.
I recommend you do this:
iClarified - iPhone - How to Jailbreak and Unlock Your iPhone 3G Using PwnageTool (Mac) [4.2.1]

It worked! Perfectly! Thanks a bunch Olethros! This is a great resource; I'll be comming back, I'm sure. Thanks again.

Hi, How is your iphone working on 4.2.1, I haven't upgrade mine yet cause I read somewhere else that it gets really slow, is that true or is it fixed in this firmware.
Thanks

It seems to be working well. I didn't have a lot of experience with the previous operating system, but the speed seems comparable.
To anyone who might be reading this; when I upgraded, it seemed to wipe out all settings, and I was wondering if it reset the phone's password to some default. I either don't remember the old password correctly, or it has been changed. Luckily it is not needed right now, but I want to set it to something easily remembered.