Television and Home Theater

I have a sony pcg 8j1l laptop and a Sanyo DP42746 Plasma TV.  I had to buy a cable that converted the VGA cable to the component cable .  I'm trying to view my computer screen on the televesion but no picture is showing up on the television.  I have the lines running into the tv on video one and the tv on video one.  Is there something I need to do on my laptop to view the computer screen on the television?

I had a problem with the headphone socket so I removed the PCB and soldered in a new component and it works fine now.  However, in the meantime I have lost red from my screen.  I have removed and replaced the PCB at the end of the gun but that has not made any difference.  HAs anybody any suggestions.  I did not damage anything (to my knowledge) when I removed the back.

Paul 

Got a Sanyo tv that is stuck on video can anyone help me