iPhone stuck in DFU mode after trying to downgrade

[SimonBS]

Hello,

I have installed iOS 5 beta 5 on my iPhone 3GS but wanted do downgrade. Therefore I connected my iPhone to my iMac, threw it into DFU mode and chose to restore. iTunes gave an error after spending a lot of time "Preparing iPhone for restore..". The error was "iPhone could not be restored." followed by the error code 1604. I disconnected the iPhone from the computer and tried again but it was the same.

Now I tried downloading the 4.3.5 IPSW and chose to restore to iOS 4 but the same thing happened. I read that it might help try with another computer so I tried plugging the iPhone into my Macbook but it is the same. It gives the same error: 1604.

Now I am stuck with an iPhone which won't get past the "Connect to iTunes" screen.

Does anyone know how I can make my iPhone useable again - or even better, how I can make it useable AND downgrade to iOS 4.3.5?

 

[SimonBS]

After I Googled this A LOT I found this tool: RecBoot which lets you exit recovery (if you have ended up in a recovery loop, meaning that you cannot do anything but recover and is getting an error when trying to do so).

After I ran RecBoot and chose to exit recovery I could sucessfully recover to iOS 5.0. I can't downgrade to 4.3.5. I will just get an error when trying to do so. If anyone knows a way around this I will be glad to hear

 

[TonyC28]

I backed up my phone before installing beta 3 and ultimately updated to beta 4....but here's what I did.
Uninstalled iTunes 10.5. Then went to the Apple site and downloaded the public version of iTunes that is available right now. Once installed, that version of iTunes had all my songs already in it and was exactly as iTunes 10.5 was, so no frustrations there. Then I plugged in my phone (which was running beta 4) and iTunes pops up a warning saying that the phone requires iTunes 10.5. I put my phone in DFU mode at which time iTunes says it must be restored. I restored it, iTunes put on 4.3.4, I then restored from my backup, and now my phone is just as it was before.

 

[TonyC28]

^ Sorry, I copy and pasted that from my older post so the version numbers are a little off. But I don't see why it wouldn't work going from Beta 5 to 4.3.5

 

[QuarterSwede]

I backed up my phone before installing beta 3 and ultimately updated to beta 4....but here's what I did.
Uninstalled iTunes 10.5. Then went to the Apple site and downloaded the public version of iTunes that is available right now. Once installed, that version of iTunes had all my songs already in it and was exactly as iTunes 10.5 was, so no frustrations there. Then I plugged in my phone (which was running beta 4) and iTunes pops up a warning saying that the phone requires iTunes 10.5. I put my phone in DFU mode at which time iTunes says it must be restored. I restored it, iTunes put on 4.3.4, I then restored from my backup, and now my phone is just as it was before.

This is correct. iOS 4.x requires iTunes 10.3 (current). Basically, iTunes needs to be downgraded as well.

 

[Ksizzle9]

Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_2_10 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8E600 Safari/6533.18.5)

I'm not calling the last poster a liar, but I've downgraded from every beta sobfar without downgrading iTunes. I would restart the computer, try and turn off the iPhone, try an do the steps for dfu and try again. Any errors I've had have Been easily fixed by " if at first you don't succeed...." u know the rest. Not sure, maybe it's just luck

 

[TonyC28]

Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_2_10 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8E600 Safari/6533.18.5)

I'm not calling the last poster a liar, but I've downgraded from every beta sobfar without downgrading iTunes. I would restart the computer, try and turn off the iPhone, try an do the steps for dfu and try again. Any errors I've had have Been easily fixed by " if at first you don't succeed...." u know the rest. Not sure, maybe it's just luck

I figured what I did was just luck too. It appears there are a few different ways to do it.

 

[dccorona]

in doing this with an iPad, my solution ended up being this:

install tinyumbrella, open in, then close it.
plug in iPad (or iPhone in your case), open tiny umbrella, start the TSS server, then option+restore in iTunes to the 4.3.3 or 4.3.5 firmware. For me, this part went smoothly, but then the iPad would not boot. I then plugged into a different computer and did the restore again, which finally worked.