My screen would not wake up when my laptop gets out of standby or hibernate (Windows XP pro.)
I have tried to play with the Power Options, changing the value of “turn off monitor”, but no solutions so far.
Any ideas?
I’ve occasionally had that problem. Try hitting alt-F5 - on my machine, it seems to refresh the screen or something.
Disclaimer: IANA tech person, have no technical expertise, etc.
Check your MB BIOS power down settings. Turn them all off and see if the problem persists.
My solution: Hold down the power button until the computer turns off 
I seem to remember that XP Pro has a known issue with the sleep function.
Ahhh, google is good.
http://forums.whirlpool.net.au/forum-replies.cfm?t=142446&p=56
Slee