Daniel Technology Group

I'm replacing the LCD panel on a Compaq Presario F700. The original screen was cracked but you could still make out parts of the screen and it was still backlit. I ordered a replacement and when i installed it there was nothing on the screen at all. I sent it back to get yet an other replacement and it still won't work. The old panel still shows parts of the screen and backlight and i can also hook up to an external monitor and it works fine. Why won't it take a replacement screen? is it possible to get two dead screens from the part supplier? I don't think it is the LCD inverter because then the old screen wouldn't work either. Is there some type of setting i have to make for the computer to recognize the new screen?

Also, when i use the external monitor and go to display settings in windows, it recognizes the default monitor but it won't switch to it or power it on.