My friend gave me her old iPhone 3G, which doesn't work.I kept getting error 21 in iTunes when I tried to restore (tried DFU). I saw that the USB connector on the phone was messed up so I took apart the phone and fixed it, and found some corrosion on the connection from the screen to the phone, and I attempted to clean that. Now I try to restore it with iTunes, I keep getting error message 21. And the screen doesn't work. The home button is responsive, as I can put it in DFU and iTunes will recognize it. Help please? Thank you. EDIT: iTunes says it has restored the iPhone to 4.0 after I did work with iRecovery. The issue now is that the phone isn't recognized on my computer unless I put it into DFU mode. I've tried multiple computers and 3 other restores lead to this same thing. The screen still doesn't work, I'm going to be getting a working one soon. All I would like is for iTunes to be able to recognize the phone so I know I only have the screen left to fix. If anyone has any solutions, I would greatly appreciate the help. Thanks!!