thinkpad 390x

I havea thinlpad 390x and the screen has gone blank! I can still see a gray glow but nothing more. I have hooked up another moniter and it works fine with the laptop. My question is, does it sound like the video card went bad or the screen is bad. I will be replacing the part myself so I would

thinkpad 390x

I havea thinlpad 390x and the screen has gone blank! I can still see a gray glow but nothing more. I have hooked up another moniter and it works fine with the laptop. My question is, does it sound like the video card went bad or the screen is bad. I will be replacing the part myself so I woul