Monitor has a message input signal out of range

Go into HP screen menu and turn off the display notification

Have you tried uninstalling the graphics driver entirely and then rebooting? Could be a corrupted driver.

Try resetting your graphic to default and reset the monitor to factory default.

You will need to adjust the refresh rate.
See my tip here: http://www.fixya.com/support/r9352855-adjust_or_change_monitors_refresh_rate

If you are getting the no input or out of range message on your screen then you will need to do one of the following:

No input
If you aren't getting signal then it means that your graphics card has failed. Make sure the video connectors are secure. If all connectors are in place and you still don't get a signal then you will need to:
Connect the video cable to onboard graphics if you were using a graphics card. If you're not using a graphics card then it means that your motherboard vgraphics has become faulty. You will need to consult a repair technition.

Out of range message
If you are getting this message then you will ned to change the refresh rate on your monitor. To do this boot your computer into safe mode by pressing F5 during boot up. Then right click on your desktop and click on properties. Then click on the Settings tab and click Advanced. Once in the Advanced settings click on the Monitor tab. Then all you will need to do is set the refresh rate down to a lower setting like 60 Hertz.

Can you please get me the make and model of the monitor? Also did you check to see if the refresh rate of the monitor matches with that of the mac mini?

I did not see anything regarding to the Power locked out function, may be it's time to call HP. Please post back what you find out from HP.
I look at HP WEBSITE: http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01632269&tmp_track_link=ot_recdoc/c01643091/en_us/c01632269/loc:1&lc=en&dlc=en&cc=us&product=3770762


Locking OSD settings
When the OSD is locked, settings cannot be changed in the OSD menu. The OSD functionality is enabled or disabled by pressing the Menu button and holding it for 10 seconds. Upon disabling the OSD, an OSD Lock-out message is displayed for 10 seconds. When the OSD is locked and an OSD menu button is pressed, the OSD Lock-out message is displayed for an additional 10 seconds. When the OSD is locked, pressing the OSD menu button for 10 seconds unlocks the OSD and displays the main menu. Identifying monitor conditions
Special messages display on the monitor screen for the following monitor conditions:

• Input Signal Out of Range : Indicates the monitor does not support the input signal because the resolution and/or refresh rate are set higher than the monitor supports. Recommended refresh rates are as follows:
• For the w1858 monitor: 1366 x 768 @ 60 Hz.
• For the w2338h monitor: 1920 x 1080 @ 60 Hz.
• Monitor Going to Sleep : Indicates the screen display is entering a sleep mode.
• Check Video Cable : Indicates a video input cable is not properly connected to the computer or monitor.
• OSD Lock-out : When the OSD is locked, the warning message OSD Lock displays for 10 seconds.
• No Input Signal : Indicates the monitor is not receiving a video signal from the computer on the monitor video input connector. Check whether the computer or input signal source is off or in the power-save mode.
• Auto Adjustment in Progress : Indicates the auto-adjustment function is active and in process.

When does the screen go blank? Also what do you have plugged into it this most likely just because your input signal may be set at to high a resolution or frequency. Once I have more information I can assist you further.
Thanks,
Lee

update ur driver

I have been having the same problem with my hpvs17 monitor when i start to use my web browser on linux distros. Now, for the next few days i am going to try my system on a regular crt monitor. if the monitor does not crash, than i will have to say that the hpvs17 monitor has a defect.It seems that when i go online, while i am in the middle of searching something, the monitor just shuts off and i get "input signal out of range".