Installing 3.0.1 on a downgraded iPhone
This post is perhaps a little late, but I’ve been a bit busy this week and so didn’t get around to upgrading my iPhone to 3.0.1. Also, I knew it wasn’t going to be straightforward given I had downgraded to 3.0 from 3.1b
I have never had any problems installing firmware on my iPhone, an upgrade has always worked fine. I have experienced problems with an iPod Touch, however. But I am aware that people have had problems, requiring a full restore of the phone.
The reason upgrading a downgraded iPhone to an interim release (such as 3.0.1) is problematic is due to the baseband version. Installing 3.1b upgrades the baseband version to 05 Something (05.10.01 in the case of b2 and 05.11.04 with b3), but the 3.0.1 release retains the same baseband version as 04.26.08, however the release is the full package, so people how haven’t yet gone to 3.0 can jump straight to 3.0.1.
To my knowledge, you cannot downgrade the baseband without unlocking the phone and following a process described on the iPhone-Dev site, but I don’t believe that works with the latest versions of the baseband.
So the process is quite straight forward as I found, and I was able to upgrade the phone without losing my data.
First, run the upgrade through iTunes as normal, and you should hit Error 1015 and the upgrade fails. Click OK and then follow steps 10-15, found here
If you cant upgrade for some other reason, then you’ll probably need to put the phone in recovery mode and restore, but steps 10-15 will still be required.
Oh yes, The tethering hack will still work.
Update:
After performing the update, a carrier update was made available, which updates the carrier profile from 4.0 to 4.4 (3.1b2+ has carrier 4.5). Downloading this breaks the tethering hack.
However, if you browse to http://help.benm.at/uk.php on your iPhone, you can re-enable it
I have never had any problems installing firmware on my iPhone, an upgrade has always worked fine. I have experienced problems with an iPod Touch, however. But I am aware that people have had problems, requiring a full restore of the phone.
The reason upgrading a downgraded iPhone to an interim release (such as 3.0.1) is problematic is due to the baseband version. Installing 3.1b upgrades the baseband version to 05 Something (05.10.01 in the case of b2 and 05.11.04 with b3), but the 3.0.1 release retains the same baseband version as 04.26.08, however the release is the full package, so people how haven’t yet gone to 3.0 can jump straight to 3.0.1.
To my knowledge, you cannot downgrade the baseband without unlocking the phone and following a process described on the iPhone-Dev site, but I don’t believe that works with the latest versions of the baseband.
So the process is quite straight forward as I found, and I was able to upgrade the phone without losing my data.
First, run the upgrade through iTunes as normal, and you should hit Error 1015 and the upgrade fails. Click OK and then follow steps 10-15, found here
If you cant upgrade for some other reason, then you’ll probably need to put the phone in recovery mode and restore, but steps 10-15 will still be required.
Oh yes, The tethering hack will still work.
Update:
After performing the update, a carrier update was made available, which updates the carrier profile from 4.0 to 4.4 (3.1b2+ has carrier 4.5). Downloading this breaks the tethering hack.
However, if you browse to http://help.benm.at/uk.php on your iPhone, you can re-enable it