Help with motherboard

I am trying to fix a compaq pres- .The caompute has built in video(intergrated) My problem is I cant seem to get any picture on the monitor at all.I have checked the hard drive,memory,power supply,ribons(cables)and even changed out the monitor.I have came to the conclution that my motherboard has went bad.Do you have any idea what I can do.Please let me know,,Thank you