Display goes dim when I turn on the wireless card.

I have a Compaq c770us laptop that whenever you press the wireless button, the display powers off/looks very dim. I already formatted and installed a clean installation of Vista with all updated drivers from the hp website and it’s doing the same thing. Sometimes it goes into an unwakable sleep mode. The device manager show everything working properly. And if you shine a light at the display to see what is going on it you can see it connecting to wireless networks!