I have been working on this computer for a few days now and have not figured out the problem. I have done research for the answer online and am now here need expert advise.

The original problem was that the onboard video suddenly stopped working. So I placed another pci video card in and nothing. I tried a third video card that I know works, using it right now, and still nothing. So I pulled everything out to see if the MB was damaged, nothing and looks fine.

Hooked everything back up and the onboard video works but now says that there is no detectible OS. I placed this hdd into my computer and booted from it with the same message. Used it as a slave and my computer said that it needed to be formated. I used the HP recovery partition to re-install windows.

Now it will get all the way up to the point of loading the OS, and nothing. The only thing that appears is a blinking cursor in the upper left corner. This will stay there until I restart the computer.

I have looked at everything and still believe that it is either the CPU or the MB. The MB does not have any breaks, burns, scortches, or blown capacitors. I have not removed the fan to look at the CPU and will do that as a last resort.

Thank you in advance for any and all help.

If it's a fresh installation you might consider re-installing the OS.

Also you could run some hardware diagnostics using UBCD or Hiren's Boot Disk.

Try memtest. If you have 2 memory sticks try to use one of them at a time.If you have some memory that you know for sure that it works try with that.
Do a test with a new PSU.
Try to get the dust away from the MB by using compressed air.
If none of these tips work post again.

Do a test with a new PSU..

i like this suggestion ,seen it many time solve problem similar to posters

Altuin, I did not think of the memtest but just did it and found one of the sticks was bad, no video on power up the other with video. The problem still exists. Right before the OS loading it is a blank screen with a dos cursor blinking in the left hand corner. Entering the Bios is the only input that I have along with changing the Bios. I have only changed to boot sequence and nothing else. I have also changed the boot sequence back to what it was, to no avail.

Thank you for the help in advance.