Monitor doesn't sleep on power off

Question

The monitor that came with my computer doesn't sleep on shutdown or computer standby. This is particularly annoying since it's an LCD, so the monitor is black but the backlight is still on. I know the monitor can sleep, which it does when I unplug the monitor cable (the DVI cable, not the power cable), use a tool, or when it reaches the inactive time set in my power plan. Specs:

HP Pavilion Elite e9262f

Memory: 6 GB

Video Card: ATI Radeon™ HD 4650

Monitor: HP L2445m

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01916917&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&lang=en&product=4057515

If it's not possible to have the monitor power off with a setting of some sort, is it possible to set Windows to run a task that turns off the monitor when it goes in standby or shuts down?

Edit: I think this is something wrong with the motherboard or video card; it's not sending a DPMS power off signal to the monitor, it's only sending a black screen.

Edit: There is also no option to change this in the (bad) HP BIOS.

Edit: Unplugging the DVI cable does not work, apparently.

Answer 1

Check if your BIOS has an entry similar to "Video Off Method".
If it doesn't, maybe a BIOS update if available can help (but to be done with extreme precaution, as failed BIOS update can brick the computer).

Quoted from Power Management Settings :

Video Off Method : The DPMS (Display Power Management System) option allows the BIOS to control the video display card if it supports the DPMS feature. The Blank Screen option simply blanks the screen - use this for monitors without either power-management or "green" features. The V/H SYNC Blank option blanks the screen and turns off vertical and horizontal scanning. If your computer and monitor were built within the last four years, I recommend setting this to DPMS.

Answer 2

You can change that in the settings: right click on desktop > Personal settings > Screensaver > Edit energy settings > Change when my monitor should be turned off. There you can just change the settings.

Note that the actual menu items might be different, I have a Dutch version of Windows, so I don't know what it's actually called. Should be something like this, though.

Answer 3

You may have done this, but:

Check the OSD menu for power save options on the monitor itself. Link to directions is here.

Check under the section "Energy Saver Feature".

Answer 4

I think I know what's going on. The HP L2455m only responds to a DPMS power off, or a disconnected cable. Windows tells the video card to send a DPMS power off signal to the monitor when the time specified for turning off the monitor in the current power profile is reached. When I put the computer in standby, Windows does not tell the video card to send a DPMS power off signal, so it's up to the motherboard. The motherboard doesn't do anything, so the video card defaults to a blank screen. My question now is how to either:

• Set the BIOS to tell the video card to send a DPMS power off signal to the screen instead of defaulting to a black screen, which seems to be impossible without writing a custom BIOS, or

• Configure Windows to run a script when the computer is turned off or put into standby (in this case, turning off the monitor).

I'm thinking that this should be posted as a separate question. (Or is that for meta?)

Answer 5

I don't know if it will be useful, but i use an free external program named "sleeper" to turn off my Monitor with a simple windows shorcut on the desktop. (i link F9 from my keyboard to the shorcut on the desktop, and so it is easy to use!)

i use this mainly to avoid to clik on the physical button of the monitor several times a day (will not work in the future because these buttons are often very fragile)

You can try it, you will see in 30s if it is compatible with your monitor.