Check in the BIOS to see if you can have the video go straight to TV out.
I have an old dell n5415 that I am using for my carputer. It has the trident cyberblade video card. I can get it to go to my tv, but I have to have it on the laptop LCD first. Is there anyway to boot up directly to the TV?? I am using a pioneer AVH-p5700 headunit that has video in. As of right now everything works great, I just can get it to boot directly into the Video out mode. Thanks for any advise.