You can see that with dead motherboard, bad IDE drives, bad RAM, dead CMOS battery and other. Dell may have it's own diagnostics to try. Did you check Dell Docs for this model?
I am a little computer savvy, so I am a little puzzled why my sister's laptop does not load Windows. She has a Dell Inspirion 1440. She needed a new optical drive and a battery, so I went out and got the replacements. I've been busy for a few weeks, and haven't put the new ones in yet. Now, she tells me it is not turning on.
The power button does light up and I can hear the HD working, but that is far as it gets. The screen stays dark and I don't hear windows trying to load. What could be causing this?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic