Hi,

I have here (2) brand new 3GS iPhones. One I was able to jailbreak and unlock quickly with no problems at all.

The 2nd one seemed to be going ok but after jailbreaking it and updating cydia it began rebooting on it's own.

Now I have tried restoring in itunes many times and the problem persists.

The phone turns on but after 10-20 sec. it reboots to the apple logo and so on.

I posted a short video on youtube to show what I mean here:

YouTube - Movie on 2009-11-26 at 01.27 #2.mov

I'm figuring this phone will need to be returned to Apple for an exchange.

Any help would be appreciated.

Thanks in advance!

Put your iPhone in DFU mode, this is explained in the genius bar section of the iPhone forum here.

Once in DFU mode, restore your iPhone and jailbreak again

Next time be careful to install and mobilesubstrate by itself as this is Likely what caused your problem.

Thank you for your reply.

Unfortunately I have tried restoring from DFU mode and recovery mode multiple times from mac and pc.

I believe this is a hardware issue sense doing a normal iTunes restore from DFU mode does not solve the issue.

Planning to go to the apple store and request an exchange.

Hi, have you tried DFU restore with original ipsw, and then normal restore with original ipsw ... after that set it in itunes like "new iPhone" ... jailbreak it ... load cydia ... load black sn0w ... it should work !

When u use update / upgrade or restore and then restore programs, accounts, contacts etc .. u will encounter bunch of wierd problems :-)

Just delete phone complete and then jailbreak with unlock ( if u use blackrain/blacksn0w .. u must fix usb service, youtube and few other stuff. All programs can be found on cydia if u add few more "unofficial repos".

And at the end ... CHANGE YOUR ROOT PASSWORD from alpine to something else !!!