I got a phone from eBay that turned on to the emergency call screen that you see after a restore to stock firmware. The strange thing is that it had a wallpaper of a little boy, probably the previous owner's son or something. When connected to iTunes it said that it was locked with a passcode, although there was no passcode input screen. All it had was the emergency call screen. I put it into pwned DFU mode and tried restoring to a custom 4.2.1 ipsw but the phone goes back to DFU mode after the restoration process. I've successfully restored several phones with this custom ipsw before so I'm not sure what the problem could be. It has the old bootrom.