[MikeBoJangles]

I recently received a replacement iphone from apple due to pixel problems. I have t-mobile and i need to activate so i tried using ZiPhone and pwnage tool/quickpwn/winpwn i have always got the (21),(1604),(1600),(20),(9),(6), and (4) errors. I have recieved all those errors. i have tried alot of methods and nothing seems to work but now i have reacher a major milestone. My iPhone seems to be completely stuck on the recovery screen i have tried to restore by using the upgrade and restore option ad i even get an error by doing that please help me

[iSirena610]

Im having the same problem..
What i heard is that you have to get the phone into
DFU mode before having iTunes restore it..
My only problem is that my phone is STUCK in restore mode
and wont go to DFU mode.. and when i try to restore
from the mode its in.. i get the 1604 error

So try getting it into DFU mode

[Broomhead]

^^ correct
Try restart your computer and changing the usb port the one your iPhone is plugged into.
These are just the first things to try. there are many others. search around a little.