John Cunningham 0 Newbie Poster

My G5 running OS X 10.3.9 will not start up. I have tries starting from the superdrive to check and repair the hard dvive but about 80% of the time the HD does not show up. I did the hardware test and disk varification when the HD did register but they both said every thing was ok. I tried reinstalling the system software and all the updates but the result was the same.
Does anyone have some other ideas?

John in Tokyo