Help with downgrading 3.01 > 3.0

[talon]

Okay, here's the situation:

I have a jailbroken 8GB Iphone running the 3.01 firmware. I want to try the IAPD video out replacement solution, however, have recently came to terms with the fact that it just won't work with 3.01 (only 3.0 is supported). Now here is my dilemma- I must downgrade to 3.0 to test this solution, AND keep my iphone activated with all associated files (contacts, etc; music and removable media such as that managed by itunes is not important to me). I have everything backed up but I am pretty sure if I downgraded that these files would not carry over from the back-up (seeing as the back-up is from a later FW). Is this the case? If so, is there any way to downgrade and keep my files? (Heck, I could even do it manually if I had to, I am desperate to get a TV Out solution that won't cost me $50+ retail)

Thanks, any and all help is greatly appreciated.

All I am asking here is this: If I reload my iphone with an older firmware, will my Itunes back-up of my phone still work?

[i.Annie]

Answer to your question is yes. But as for what you're wanting to do, I don't think 3.0.1 has anything to do with limitations...as far as I know. I can't be 100% sure though. It's said that the update from 3.0 thus far (excluding 3.1 beta) has no effect on anything except for the SMS vulnerability. That's the only reason why 3.0.1 was released, to fix that vulnerability.

[talon]

While your right in that the 3.01 software is reported to have only changed the SMS flaw, it (being a new release) has a new "name" or reported FW and that in itself is what I believe is making the replacement IAPD file incompatible. I have read many accounts and even tried myself to replace the IAPD file with the new one to get my TV-out connector working with non-apple cables with no luck. It seems it doesn't understand the 3.01 software, only the 3.0 has had any luck which is strange because that would mean the firmware number/version is actually encoded into the file. I have tried with 3.01 and it strips all non-data or charging cable connectivity, such as video, previously supported bluetooth, and other adapters. Thanks, I will try and report back my luck and any findings.

[i.Annie]

Well go down to 3.0, wouldn't hurt to try =) Shift+Restore to older FW... lol in case you didn't already know.

[talon]

Update:

Wow, in my troubles I managed to find a flaw with the "original" firmware files hosted on MMI. I downloaded the Iphone 2g 3.0 ipsw files and Itunes 8 did not allow them to be used to restore. The error was "This firmware file is incompatible". Just like that, no error code. I assure you those were the right ones for my phone, but just for good measure I decided to try the 3g file too, in case they had been swapped. Same error. By stroke of luck I ended up finding the 3.0 firmware I downloaded for RedSn0w to "point" to [on my harddrive after trying the two hosted here], to use the 3.01 firmware with it. I decided to try this firmware and now itunes just finished up loading it onto my iPhone without error. So if you are stuck in the same boat as I am and need help downgrading from firmware 3.01 (NOT 3.1 Beta for Developers) to 3.0, use the one on RedSn0w's project page. Downgrading from and to these firmwares will only help you if you would like TV-OUT to work or if you just simply experience problems with 3.01. The back-up is 50% completed, I will post tomorrow how this turns out.

Okay so downgrading officially through iTunes from 3.01 > 3.0 works, and the back-ups (from FW 3.01) are still compatible and loaded onto my iPhone fine. My iPhone is now activated and I can only assume fully-functional and loaded with my old data. Jailbreaking and IAPD replacement- up next! This is the first documented downgrade from 3.01 to 3.0 that I could find.

[talon]

Okay so apparently the 3.0 fw doesnt work with the IAPD replacement, and I cannot seem to downgrade any further due to the same error as before. I am looking for more hosted firmwares and trying them all, so far to no avail. Will try and keep you posted.