Latitude D610 won't boot

I was using my Latitude D610 and it was working when the low battery light started flashing, so I shut down the computer and plugged it into the adapter. The light went on as if it was charging.

Now when I press the power button the power light comes on, three lights near the volume control turn on, then go off and I can hear the Dvd drive and the Hard Drive starting up but then nothing. The screen just stays blank and nothing else happens.

Anyone have any ideas?

Not having any luck with Dell Latitude laptops! My D600 has just stopped working as well, doing the same thing as it did before, which required a motherboard replacement.