You may discover that, upon switching from using an HDMI cable to using a SCART connector, your PlayStation 3 console no longer displays images. This may be due to the fact that your PS3 is unable to automatically recognize the SCART connection, which can be fixed by resetting the display settings of your console.
Switch from HDMI to SCART on PS3
Turn off your PS3, and connect it to your TV using the SCART cable.
Press and hold the Power button for a couple of seconds until you hear a double beep.
When you turn on your console, your display settings should be restored and you should be able to view images on your screen.