Gigabyte motherboard with AMD Athlon 1.2Ghz

Hello,

I have a dekstop that my my friend built for me a few years ago. It has Gigabyte motherboard with AMD Athlon 1.6Ghz CPU. Two weeks ago it stopped booting up. The power lights are on and fan is working ( making a whirring noise) and hard drive light is red and nothing is displayed on the monitor. When I try to turn it off and on several times, some times the the hard drive will turn green and PC will boot up and start working without any problem. Yesterday, it quit working no matter how many times I swtiched it off and on.

The power seems to be Ok. The cooling fan is working. I removed the memory and restarted but I did not hear any beeping noise. I just the whirring fan noise and the hard drive light is still red.

I am wondering if its a motherboard or a hard drive problem. What test can I do to make sure the hard drive is ok. Unfortunately I don't have another PC to connect this hard drive to.
Any help will be appreciated.

Dave