If everything else works well, it's likely the game console. There have been some instances where HDMI outputs would cause the screen to blank out due to HDCP, but those protections aren't applicable to the component cables.
While using my xbox 360 the LED in the corner flashes all the time, every couple of seconds the screen will go blank then the picture reapears, but it only happens when using the xbox 360 Via Component
My Sky Digital Box Via Scart is fine and my PC Via HDMI is fine
It is a Samsung LE37A558P3F