Display problem

Dear,

Recently i am having a strange problem. computer starts but there is no display in the monitor. after few hours later when i power on the pc it starts with display. but when i restart there is no display again. first i have thought the problem might be in the monitor. then i have boutht a lcd monitor(benq). but few days later the problem reappears & still continuing. while starting the computer i do not hear any kind of beep code. i have also plugged vga cable to my built in graphics card, but the problem remains. my pc configuration is------

processor: intel pentium D 3.2GHz

hard disk: 320GB

RAM: 2 GB

Graphics card:nvidia pci express 256 MB
i am using vista ultimate final

You have onboard video, so try completely removing the graphics card and living off the onboard video - does the problem still persist?

Also, is the RAM in two sticks? If it is, try removing one of them (put it on something non-staticy, like a lino or wood tabletop) and see if the other stick works. Try swapping the stick used if the problem still persists.

There could be something touching the motherboard or graphics card which is causing this issue - I have a PC that exhibits this problem because it's in a case it isn't designed to be in, I have a piece of cardboard under the mobo so it doesn't touch the case (and short out), and therefore the mobo is higher than it should be so I have washers under all the cards to get them to the right height so they can be bolted down. The result? It'll mostly turn on, but sometimes a vital pin on the graphics card won't touch the socket on the mobo so the PC won't POST

-dav7