The exact same thing just happened to me tonight, I successfully done my friends phone, and then tried to do his dads, and it died on me gave 1600 error, and could do anything with iphone switch off nothing. so I tried shift restore agian, nothing. Itunes recognised it but just said in recovery mode.

So I tried ibrickr, to boot out of recovery, nothing, so I thought i'll delete the custom file from pwnage file on desktop, and started pwn againon expert mode and when I got near the putting phone in dfu mode it kicked the phone into life.

I then restored it back to original firmware which was 112, and was left with emergency screen, cable to itunes picture. then I got the phone in dfu, (white screen)and shift restored the custom file I had created whilst getting phone to work.

So try that locate original firmware file download it, and see if pwnage can release your phone. Then retore to original firmaware, then no need to activate or anything like that, just follow winpwn agin to build file, and put phone in dfu, then restore to new firmware.