Last week, I called AT&T to have my iPhone 3Gs unlocked by Apple under AT&T’s new unlock policy. I had already unlocked this phone using Ultrasn0w, but I wanted to see if I would be able to just do the IOS updates using redsn0w and that is it. I have to use redsn0w, because I have baseband 06.15.00 on this phone.

Well, it turned out that yes, I can just use redsn0w, but I still had this annoying issue with MMS. In order to fix that, I needed to jailbreak the phone again.

Here is the procedure I used.

Again, this is an iPhone 3Gs running IOS 5.0.1 baseband 06.15.00 unlocked using ultrasn0w. I called AT&T with my IMEI number and had them send the unlock request to Apple. I got the email pretty quickly from AT&T telling me my phone had been unlocked and that I just needed to restore it to activate the unlock.

Software installed/downloaded:

OS: MacOS Lion 10.7.3
iTunes 10.6.1

First, connect the phone to your computer using the USB cable.

From iTunes, right mouse click on the phone under DEVICES and select Backup.

With your phone backup complete, create a custom IPSW IOS installation package using redsn0w:

Unzip the redsn0w download, and execute the

Select Extras.

Select Custom IPSW, and browse to the location where your saved you IOS 5.1 download (iPhone2,1_5.1_9B176_Restore.ipsw).

On the next screen, select whether you have the old iPhone 3Gs or newer. I have the original 3Gs, so I selected No.

To determine which version you have:
Put the phone in DFU mode. In MacOS Lion, bring up System Information by clicking Apple/About this Mac and selecting System Report. Then, click USB and look for Apple Mobile Device (DFU Mode). Look at the Serial Number line for iBoot. The number following iBoot will help you determine whether your 3Gs in the old version. 359.3 is the old version. Anything above that is the newer version.

This will create a file called NO_BB_OLDROM_iPhone2,1_5.1_9B176_Restore.ipsw. This is the file you are going to use to restore your iPhone from.

Ensure that you have your phone connected to your computer. Put the iPhone in DFU.

Here is the procedure I have used to put the phone in DFU mode:

With the phone on and unlocked, hold the Power and Home button. When the screen goes completely black, count to 2. Then, release the Power button and remain holding the Home button for 10-15 seconds. iTunes will report that the device is in recover mode. Now, I have done this several times, and have fairly confidently determined that this is not DFU mode. If you try to restore with the phone like this, you will get a 1600 error. This is what I have done consistently that last few times that has worked every time. Once in recover mode as determined by iTunes, I fire up redsn0w again. Click Extras, and Pwned DFU. This quickly puts the phone in DFU mode, so you can restore your custom IPSW.

Once in DFU mode, go back to iTunes, select your phone from DEVICES, if not already there, and hold the option key and click Restore.

Browse to your newly created custom IPSW file (NO_BB_OLDROM_iPhone2,1_5.1_9B176_Restore.ipsw), and click Open. IOS 5.1 will be installed and the phone will reboot and prompt you to restore settings from a backup or setup the phone as new. Now, because Apple had unlocked my phone, at this point I got the message congratulating me for successfully unlocking my phone.

Cool. Except for one problem. I was hoping that this (new redsn0w + IOS 5.1) would also fix the inability to send MMS messages without using iMessage. Well, it didn’t. I am using a T-Mobile SIM in the phone, so I thought I might try setting Cellular Data APN or the MMS APN to either or Neither of these worked.

So, I went back to jailbreaking (untethered supported). With the phone connected, I fired up redsn0w again, and this time selected jailbreak. Again, the phone needs to be in DFU mode. This took me a couple tries, because the first time it did not appear to go through the jailbreaking process. But it did the second time.

Once the phone rebooted, I verified that I had the Cydia icon installed. Funny note, it was right back where I had it before I started this process.

I started Cydia, and updated as prompted. I go the developer route, and update everything.

Once updated, and Cydia or the phone was restarted, I navigated to Sources, clicked Edit and Add to add the following repository:

Once the repository was added, I tapped the newly added repository to browse the packages available. I selected MMS Tmobile Fix, and installed it.

Then, I navigated to the phone Settings/General/Network/Cellular Data Network.

Cellular Data APN:

And that was it. So, I guess in the end, I only got rid of needing Ultrasn0w, but at least I have MMS working and have IOS 5.1.