my guess is you need to find the encrypted RUU from somewhere. You may be able to find the decrypted RUU then you can use a tool to make it encrypted (ruuveal?) That should let it run when you are locked and s-on
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?