My dell 1721 comes on for 2 seconds after pressing the power button then turns off with no display? The screen stay's black. I got a blue power light. fan runs for 1 to 2 seconds then goes off. I took it totally apart but found nothing. I have tried the battery in and out with ac power. I have held down all the F key's and still nothing. Took ram and HD out. Reseated CPU. I am at my Witt's end here. I would be grateful for any help here guy's. I have read so many threads on this problem but still no luck. I fear it's gonna cost more than I can afford to spend. Any tip's?