Not booting Not beeping

[nanncy]

My computer although a bit older was running fine till it was shaken a lot by a blow on the case.It restarted by itself, worked for a short time and frozen. Thereafter rebooting efforts went up to frozen screens only.Ultimately the machine refuses to boot-up.There is black screen only.There are no beeps at startup!-No that is not exact-Rarely there are 3 short beeps.Yes very rarely that 3 beeps only.The HDD is trying to start and ends with a clicking sound.Led in MOBO is lighting.CPU fan is working.I tried with a number of RAM sticks but no better results.On checking the PSU output voltage it is seen that there is a +/- variation upto 8% .Could this be a culprit in this case?The Monitor also was checked and found OK.Applied thermal grease afresh.Is it of so much importance to apply a good quality thermal grease? (I suspect the quality of the thermal grease already applied)
What could be the problem?
Anybody could help me please?

The specs are:
Intel D845GVSR MOBO (on board graphics)
Intel P IV 2.8 Ghz
Ram 512 MB PC 333
USB mouse
PS2 keyboard

[xavier]

check all the connections first.Dis connect everything except leave 1 stick of ram,video,cpu with fan hooked up,monitor hooked to video.Turn on pc and see if you get a display?If you get no display you have a hardware PBLM. Do the fans spin when you turn on?

[nanncy]

yes ,the fan spins, HDD is trying to read and makes a clicking sound, CD Drive lED flashes for a while but nothing to the monitor.Each time I have to turn off the machine by pressing the power switch for a while.

[patio]

If that click is coming from the hard drive that drive is getting ready to fail...
DLoad and run the FREE diagnostics from the drive manuf. site...

This will tell you the health of the drive.

[nanncy]

But even with the   HDD disconnected,   monitor does't display anything.Is it  necessary to have the HDD to enter the BIOS? I cant just view the BIOS either. How can I test if the on-board graphic chip is failed? Any suggestions?

[Aegis]

Yes, you should get BIOS first.

Actually, depending upon the system, you'll get a short display for the video card and video RAM, and then the system will go through the Power On Self Test (POST) procedure before it attempts to boot an operating system.

[patio]

Try another monitor...
Is this onboard graphics or an add-on card ? ?

Sorry i just noticed you stated this was onboard...
Borrow a known working vid card from a friend and post the results...