Sir,
My PC set is:
 a.. CPU - AMD K62, 450Mhz , 100Mhz FSB
 b.. MB - ASUS P5A-B, Super 7
 c.. MEMORY - 128 + 32 Mb SD Ram
 d.. Graphic card - Trident 3D AGP 9750
 e.. Sound  Card - Sound Blaster Pci 512
 f.. HDD( Primary)- 4.3 GB Fujstu, (slave) 2.1GB Fujstu
 g.. PS - AT 250 watt
 h.. OS - Windows 2000 Pro + service pack 4.

It was in perfact working condition, until I removed its HDDS for a short time. Now it fails to boot. It is behaving erratic. Most of the time, I don't see any display and some time I see color patterns on the monitor after switching on the computer. The bios display does not reach till detection of IDE devices and freezes before this stage. Sometimes, I hear one long and followed by THREE short beeps. Several times, the beep is normal and display shows the testing of the memory etc before freezing.

I have checked all the devices for correct connections. Power supply voltages are correct. CMOS battery is good as system time is retained. Something wrong with BIOS...??

Please advise...  

jawanda56   Make sure you have the hard drives connected properly. If you are using one ribbon for both drives the main drive needs to be at the end. Try switching how you have them connected. Since the freeze-up happens while reading the hard drives I think that the problem is with the hard drives.For Tribert:

Hard disk drives are connected correctly. It seems the problem is not the HDDs. The computer starting sequence does not reach that stage, and if at all it reaches the detection of drive, it tries to boot correctly. I still feel, the problem has something to do with the Bios. Is it possible to reinstall the BIOS?

Any other suggestions...

jawanda56 SO you get VIdeo?  or is it wacky?   AGP can be tricky,  have you got a pci vid card laying around to try?Yes some times it does START off with good video, I have also noticed on boot up when it displays the bois and detects the processor, it used to show AMD K62-450Mhz, but now there appears AMD K62-495Mhz. Sorry no pci video card lying around to try.

Yes some times it does start off with good video, I have also noticed on boot up when it displays the bois and detects the processor, it used to show AMD K62-450Mhz, but now there appears AMD K62-495Mhz. Sorry no pci video card lying around to try.
I waited several days for some good tips to come. Finally, dismentled the complete CPU. removed all components and reassembled. Cleaned all parts (although they were already CLEAN). Rearranged the IDE devices as per Primery/Secondary/Master/Slave order. The computer started well and revived. I'm using it since over a week. No problems, except, it looses display when some demanding application is being used.

Thanks u all for the help...  

jawanda56