Monitor won't sleep

[Omail710]

I am running Vista Ultimate 64 bit, SP2 on an HPd5000t with an HPw2338h monitor with GeForce GTS 250 video card, driver 8.15.11.8627.  Until 2 days ago, when the computer went to sleep so did the monitor with the power button turning from green to yellow.  Now when the computer sleeps, I get a black screen with a moving white box saying "no input signal" with a red, green and blue band at the bottom.  If I try to use the power button, I get the same box with the message "power button lockout".  Other than adding speakers, and Windows updates (since the problem began), there have been no other changes.

How can I get back to a sleeping monitor when appropriate?

[Omail710 · Accepted solution]

With email help from Bibin, I was able to solve my own problem.Bibin suggested the following site:

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01632269&cc=us&lc=en&dlc=en#N1486

which led me to the answer.  Using the monitor controls, I went from Menu to OSD to Management and found Power Saver was off.  After setting it to ON, the monitor now sleeps properly.

I hope this may help someone else with the problem.