I bought a Sony BDP-S350 Blu-Ray player a while a go, but recently had to return my Samsung A686 Screen and used an older lower resolution monitor. When first switching back to the older screen I got the error message this screen does not support this resolution aargh!
Any way I found the manual online
And you wait 30 seconds with out doing anything, this means that all the menus will have defaulted back to a known state. Then press and hold stop on the player (not the remote) for 10 seconds, then the player defaults back to the lowest resolution and your ready to go again.