Rob, if you have the PVP upgrade, I don't believe there is a way to shut them off and prior to the PVP upgrade there was a place in the menu that allowed you to shut off any of the three (composite, 'S' or component) outs and the manual recommended you do this. When I first got the PMDT, I inadvertently shut off all and had no video and had to get the proper sequence of remote buttons to fix it. Madrigal told me to leave them on and that those instructions should not have been written like that. If you are reading the instructions to the last software upgrade, they tell you to turn on the the video outputs, but as I indicated there is as far as I have been able to tell with the PVP, no way of shutting them off. I would just test them to make sure they all produce a picture before proceeding if you are doing the software upgrade.