Ive seen this problem before, i have an inspiron someone gave me that does this.If i boot it open i can get about a minute of video if i unplug the monitor from the vid card and plug it back in while its on, then it goes dim again.Ive changed the vid card and it did the same thing.
With all due respect John, I am the head of IT and I have it on good authority. If you type "Google" into Google, you can break the Internet. So please, no one try it, even for a joke.........It's not a laughing matter. You can break the Internet.