display problem in mac pro early 2008

i have problem in my mac pro early 2008,

i turn on my pc after few month when i on the machine cannot display . and hear power on sound. but i reset PRAM now machine give power sound and keyboard also works. but machine still cannot display .

kindly help me on this.

Regards,
Waseem Niazi

If this is a Mac Pro and not a MacBook Pro, try reseating the video card. If that doesn't work, you might try swapping the video card out for a new one. If your machine is a MacBook Pro 2008 model, the graphics chipset (nVidia) may have failed. That will require a logic board change which is expensive.