Hi; I have an iPhone 3G that was unlocked and jailbroken, I now want to restore it to factory settings to give it to a family member who will use it on the carrier that it was originally locked for (O2). I probably boo booed by plugging into iTunes and selecting restore, it now will not restore and is stuck in DFU mode (USB iTunes Logo) and I keep getting the 1015 Error Message. I did not write down the firmware version but I think it was 4.2.1? When I originally had this phone I was running Snow Leopard, I am now on Mavericks. I have searched Google and have put the phone into black screen DFU Mode but I still get the 1015 Error Message. I think I need to re-install a custom baseband / firmware by using an option when opening iTunes however I cannot remember how to do it and need a guide. Can someone help please??