Black screen of doom windows 7

Hi all,

I have an HP G62 laptop with windows 7 x64 and got The Black Screen.
here are the symptoms:
-black screen,
-no cursor,
-no beeps,
-no sound, except fan, and hard disk
-The hard drive spins trying to boot then stops after a couple of minutes tries again.
-the fan runs constantly
-the caps lock led is on and off
-no CD in tray
-At power up I do not see the ( underscore on top left corner) , F8 does nothing it is totally black.

I have so far tried to
-power then F8 before normal boot
-plugged external monitor (in case of display failure)
-changed the Ram sticks (in case of display failure)
-hard or forced reset : Performing a Hard Reset or Forced Reset HP Pavilion dv5000 Notebook PC series | HP® Support

nothing seems to work
any suggestions? other than obvious toss?
Cheers

Unplug A/C and battery, hold power button to release residual power, plug back in A/C to see what happens. Then plug in battery to see if it can power PC after reset.

Next take the RAM sticks out to see if you get beep codes indicating life in the mobo.

If so replace them one at a time to see if you can get any display.

If not remove hard drive to see if it is blocking boot, although you should get some image on your external monitor if there is still a display adapter or mobo life.

If by slim chance the HD is blocking boot, try booting into a disk to see if it comes alive. You'd then need to slave the HD to another PC to rescue files, wipe it and replace to reinstall.

Report back results on these and one of the hardware guys will probably recognize the condition.

Sometimes the wire harness on the laptop monitor needs reconnecting, for which there may be a video for you model if you google it.