Although the PS3 usually detects the video connection type automatically, the video output setting can be changed manually from the PS3 settings sub-menu. Changing the video display setting manually allows you to keep the HDMI and composite AV cables connected simultaneously. Composite AV, also referred to simply as AV, is the standard definition video setting used mostly by older televisions or any TV that does not support progressive scan or other HD video formats.
Instructions
1
Scroll to the "Settings" icon on the PS3 main menu.