her into the diagnostics.

Are you saying that at NO point, does anything show on the display?

Can you tell if your display backlight is turning on? Turning on very briefly, then going out, etc? Look particularly around the very edge of the display screen. You may see some level of backlighting even if the entire display remains dark.

On some laptops you still can just barely make out that something is actually shown on the display screen when the backlight doesn't turn on. It can help to have a source of bright light to move about and shine off the screen as you look for any images/text.

Also, while you're doing this, try pressing the key combination that cycles through the display choices (LCD/external/LCD+external) For example, on my Presario I think it's the F3 key. Yours may be something different. Check your manual. As was mentioned earlier, attaching an external display (including a TV to the sVHS port if you have one) could help diagnose this as well.

Something else one can try is to boot a bootable diagnostic/repair diskette or CD/DVD. With and without the HDD installed in the laptop.

You can try booting any one of the many diagnostic/repair/benchmark downloads. A download that provides repair/recovery tools is freeware Knoppix. It comes in CD or DVD flavors. The DVD contains more tools than the CD version. Knoppix boots your system in Linux, and the user-interface is graphical...like Windows. and helps bypass any problems caused by your HDD or a corrupted OS.

You can also try any bootable 'rescue' CD that came with the system.