1. If you're getting power, suggest tapping the 'F2' key as soon as you turn on the unit just to confirm you are not even getting into the bios since some people report that same problem when they are only having a problem getting into the Windows desktop.
2. Try connecting an external monitor too as already mentioned just to confirm it isn't a problem with just the notebook screen.
Otherwise, if the system is not 'posting' or getting into the bios, the problem could really be several things from memory, motherboard, and/or GPU as well as other things.
Unfortunately, not sure what is the most common reason for this problem, but if you can do them safely, try some of the easier things like removing the battery, removing additional memory, or even removing the hard drive, just to make sure they aren't related.
A bad vga card and/or motherboard are definitely 2 things that could be causing the problem though if it's still not working though, but unfortunately, you cannot be sure until you have some good hardware to try.
