4 yr old HP laptop I think it's dead, Jim...

Ok. Not completely dead. I have a 4 yr old HP laptop which was working fine yesterday morning, then I pit it to sleep (as I usually do - I only "shut-down/ restart" once or twice each week. This time, when I wiggled the mouse to restart it, the screen came on, but the touchpad would not move the cursor. Nothing would (enter key, arrows, PgUp, etc). So I used the power button to shut it down.

When I try to power it up again, the initial lights on the keyboard come on (so it has power), and it checks the DVD Drive, but then nothing... the screen stays dark. The internet light never moves from Red to White, so the boot up is not getting that far.

I've removed the battery... no change
Repeatedly hit F8 as it's starting.. no change
I then, eventually have to use the power button to shut it off.
it has been on the off position for hours between the last test, so it's not in an overheated state.

I'm at a loss as to what else to try!
Any suggestion welcome.