Thanks for your help.
I performed the following steps:
1. I put the iPhone in DFU mode.
2. Started TinyUmbrella.
3. Clicked on "Start TSS server."
4. Started iTunes. It popped a window saying that it found a device in restore mode.
5. I clicked shift+restore and selected the iPhone1,2_4.1_8B117_Restore file.
6. iTunes said that it's preparing the iPhone, iPhone restarted and booted normally back to 4.2.1.
7. iTunes threw error 1646.
Please see the iTunes updater log at the following link:
#1479772 - Pastie
Please let me know what you think.
As I said, I've never seen this particular error before. It's very strange that you can't bootstrap from DFU.
Originally Posted by pannenko
Do you have access to a different machine? Preferably NOT x64 or Vista (actually preferably a Mac)
I agree with Olethros. Not sure why you can't bootstrap it.
Are you sure you are in DFU mode ?
In DFU mode, the screen is dark/black.
If you see the picture of the usb cable & CD on the screen, then you are in recovery mode
The screen is indeed black -- no image and it does not respond to buttons.
I'll ask one of my friends to use her mac and I'll see what happens. I'll keep you updated, but it might take me a couple of weeks before I have a chance to play with the mac.