Pc turns on but not the hard drive.

[Burntuptoast]

I have an hp 505b microtower pc and it recieves power when I turn it on but the hard drive light does not. It will ocassionally flicker allowing me to use the pc for 20 minutes before it crashes. What is the problem and how can I fix it?

 

[CountMike]

Check HDD as a prime suspect.