Stuck at POST screen and other odd symptoms

My friend's Alienware desktop started showing a blank display, no imagery at all. The power light on the monitor would turn blue when first booted, then in a few seconds go to orange and the display would say "no signal". The monitor works fine when connected to another computer.

The monitor is an HDMI monitor, but the computer has both HDMI and DVI. He has been using HDMI. So my friend bought another cable, an HDMI to DVI cable, and connected the monitor to the DVI output.

Now when he turns it on, it goes to the screen that shows the Alienware logo and says "press F2 for Setup, press F12 for Boot options". But neither F2 or F12 work, the screen remains. We tried a different keyboard, a wired keyboard this time, still the same result, pressing F2 and F12 do nothing . Also checked the keyboard by connecting it to another computer and it works fine. And switching back to the HDMI cable still gives a blank screen.

Any ideas? It seems like a bad motherboard since F2 and F12 have no effect, but I am not sure.

Thanks

What kind of video card does this system have? Is it a discreet video card or is it an onboard card?

My suggestion first would be if you have a discreet graphics card, such as in a pci express slot, either remove the card, and swap it out with another video card "if you have one" or if there is onboard video, hook up to your onboard and try to duplicate the issue.

A faulty video card will make a failed post.

Also, if you haven't, try to clear the cmos on the board. Sometimes restoring to default will fix issues.

If neither of these fix the issue, while computer is powered off, remove the RAM sticks, and reseat them.

If doesn't work, then it may be the motherboard going faulty.

Today my friend turned the computer on it worked.

Thanks for the tips, if it fails again I will try those. It is a discrete video card, btw.