I was running 3.0GM by using the Option+Update method from 2.2.1 and when 3.0 was released I forgot I need to go back to 2.2.1 before updating and I updated it... Anyways got to 3.0 unlocked and unactivated. Then I put it into DFU to downgrade on iTunes 8.2, it gave me a 160x error and from then on it stopped detecting the iPhone... I have tried plugging it in with different iTunes versions on different computer on OS X and XP but nothing seems to work...
I know it is connected and nothing is wrong with the cable or USB port because it charges the phone just doesn't connect... Also on windows when I quit iTunesHelper.exe, XP detects unknown device on USB and tries to install hardware but nothing happens...
Please let me know if someone has a fix for this thanks...

Note: iTunes detects my brothers iPhone 2G on 2.2.1 without a problem and sync's it as well...

Bump...

Does anyone know anything that might help???

i have the same problem, but i have no idea on how to solve this. i also updated to 3.0 and then my pc or mac cant detect my iphone. if you got to solve this, please update in this post, if i find something i will tell you.

I have not found anything yet, but if i do i will definitely let you know and thanks....

still i have this problem. my mac can charge my iphone if i connect my iphone through the dock to my fm transmitter, and then with the usb cable to the mac. but if i connect it directly, my mac doesnt detect it. anyone has solved this? i cant have my new music in my iphone cause of this.

A quite old thread,but might help u

http://www.hackint0sh.org/forum/f136/20012.htm

My problem is very similar but I don't think that thread can help because I can't get DiskAid/iTunes to detect it in any of the modes [I also do know the difference between Recovery and DFU], and my iPhone is unlocked but not activated so I can't really SSH onto it and thus can't use WinSCP/Fetch etc. to replace the lockdowned file... Do you have any other suggestions?

Note: I do get power when plugging it in to USB/AC just doesn't get detected by iTunes/PwnageTool/Redsn0w/iRecovery etc.

Have you tried redsnow to jailbreak and to put it in DFU mode and let it jailbreak and activate?

EDIT: Don't forget, you need the IPSW from the GM not the one iTunes downloads now, when redsnow asks for it.

I'll try that, I just recently deleted my copy of the GM build will download it and let you know what happens, I can't believe I didn't think of it, but I doubt it will work since the computer doesn't detect the iPhone... Anyways will let you know what happens as soon as I can... Thanks...

Thanks a lot for all your help [Gi0 & schalkse]. The information provided the both of you helped me to somehow fix the iPhone. I used redsn0w with the GM version of 3.0 to get iTunes to detect it and I realised that the lockdowned file had got corrupted when I updated from 3.0 GM to 3.0 and that's probably what caused it to give me the above mentioned issues... Anyways Thanks again I really appreciate your help...

Regards,
HomeGrown