Old(ish) full tower in need of some TLC. Help please.
Okay so I have been in the market for a new PC and I got my dad to give me his old one that he never uses anymore. It's a full tower with an Intel extreme 915p pf4 motherboard, I'm not sure about the graphics card but I know when he bought it, it was one of the nicest, so he says. 4 sticks of 4gb ram I believe, A 500w power supply and a Intel i7 processor.
Now the problem is that it has about a year or so worth of dust on it, I plan on getting an aerosol can and cleaning it all off. I don't know if dust would be a factor but I'm not getting anything to the monitor(s) he gave me with it through HDMI or DVI. It turns on and it sounds like everything is running but for the life of me I can't get it to display anything. He thinks that a while ago the HD crapped out and I need a new one but I'm suspicious of the motherboard itself. Is there anyway I can figure out just what exactly is wrong with it before I go spending hundreds of dollars on hardware I might not need? I can supply pictures if needed. Thanks for any help.