No BIOS screen?

Recently i got a computer from my friend, an HP pavilion a350n, all stock. He tested it out at his house and EVERYTHING worked perfectly fine. A week later we brought it to my place, got it set up and went to turn it on to find no picture on the monitor whatsoever. So i tested it with my laptop and the monitor works perfectly. So i checked around and everything was connected right inside the tower but the hard drive made an odd, slow, clicking sound. So i took it out and put in another good one i had, this one is doing the same thing! So i tried changing the video card, with no progress, still a black screen. Power goes to everything, but that doesnt always mean the PSU is working correctly, but even if it wasnt, and the video card was working, shouldnt i still see the BIOS screen, thanks to the mobo's onboard battery? This is really frustrating me and some help would be MUCH appreciated. Thank you