Screen black on wake up

[cduane]

I am having a problem that is driving me nuts! I have an HP Presario x1460CA laptop about three years old. Occasionally it will not wake up from sleep or standby mode. The computer works as I can connect it to an external monitor to see the screen. The screen is black and the back light works as when I press the button that turns off the screen when you close the lid, the screen gets darker. I have upgraded the BIOS and XP is upgraded to SP2.

SP is Home Edition V2002 SP2
Processor is an Intel Pentium(R) M at 1500 MHz
598 MHz, 512 MB RAM

Eventually it will come on after a hard boot. I have had several technicians look at it and they can't seem to find anything amiss.

Any suggestions would be greatly appriciated.

 

[Tmagic650]

Check the Sleep/Hibernate settings... You may have to reset them

 

[cduane]

Thanks for your reply. Sorry about the spelling error, I should have spell checked before submitting.
You may be on to something here. Under Power Options Properties/Power Schemes the setting is "Portable/Laptop" and when Plugged In the settings are "Never" for standby and hibernate. I have been leaving the lid open and not touching it to see if it could be bad connections to the lid. The unit will eventually go into standby or hibernate mode (how do you tell which?) and when I move the mouse nothing happens. When I hit enter on the keyboard, the hard drive runs and the computer wakes up but with a back lit black screen. I have connected it to a monitor and everything seems normal.