Can't Restore

Hi all,

I've run into an issue. In normal recovery mode I was getting error 21, so I followed Big Boss's instructions and got the phone into DFU (solid black screen) and for the life of me I can't get around error 1600.

I've searched this forum and googles it with no luck. Any other options?

I am coming off 5.0.1 JB on my 4S.

 

Thanks, downloading IPSW now. How do I navigate to it from iTunes? I can probably google it but since you replied I thought I might start by asking you. Thanks

edit: Held down alt, selected it, no dice. Still have 1600 error code.