Uh, Remember that once you play on a Specific HDtv the PS3 Saves it's setting's so when you go on another T.V you might hear that little sound when the ps3 boot's up, yet the screen will be black. what i do is i just hold on the power button for a couple of second's and let it reboot itself.
If you've done this before or already knew this, sorry for applying this useless info on you then. XD