Monitors sleep and won't wake when user logs off

This a Windows 8 HP Pavillion which has just had a new graphics card fitted. The new card is an Nvidia GEForce GT640. There are 2 monitors connected.

The problem now is that when a user logs off, we see the  screen saying that the user is being logged off. Then the screens fade to black and wont come back on with any command from the keyboard.

The work around is to unplug one monitor and plug it back in again. As soon as one monitor is disconnected, the other one wakes up to show the login screen. Then when the cable is re-connected, that monitor wakes up also.

What is the fix for this?
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Davis McCarnOwnerCommented:
In an elevated CMD window, type POWERCFG -ENERGY to produce a report about power management issues.
Must be the connection of the second monitor,
What make is the Windows 8 HP Pavillion desktop?
How do you have the power settings for the secondary monitor?
If the default monitor has a power saving setting that wouldn't apply to the secondary so when the default is off the 2nd one cant run?
Try and disable Power Savings in the BIOS
Do you have extend my desktop or clone mode or dual mode enabled?
Is one monitor digital and the other analog?
Are both connected to the video card

If it helps
HP Desktop PCs - Computer Starts but Monitor Remains Blank (Windows 8)

HP and Compaq Flat Panel Monitors - Flat Panel Monitor Displays Message about No Signal, Signal out of Range, Sleep, or Power Save
TownTalkAuthor Commented:
I shall check the power settings today.

The Model Number is HP Pavilion p6-2019uk running windows 8 Home Premium

The power settings within windows have both monitors set to sleep after 3 hours of inactivity.  I shall check the BIOS power settings today.

The desktop is set to extended

One monitor is HD with a DVI cable attached to the DVI port on the graphics card, the other is a VGA monitor plugged into the VGA port on the graphics card.  Since i Purchased the machine in January I have been using the same setup but through the inbuilt Intel Graphics card on the motherboard, but the VGA monitor was plugged into a second DVI port using an adaptor with the HD monitor plugged directly into the first DVI port.

There have been no other issues with the monitors loosing signal or sleeping only when the user logs off, all software works fine with no issues, videos and DVD's have been tested and are not a problem.
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TownTalkAuthor Commented:
Bit of an update.  I tried the Powercfg - Energy command and it ran fine and said I had 20 issues but when I tried to open the report it said there was no data present.

I found last night that there appears to be a phantom monitor on the system.  With the new graphics card attached the screen resolution settings in Windows 8 show my HP HD Monitor by name as well as my Viewsonic VGA monitor but it also shows a 3rd Generic Non-PnP monitor attached that isnt there.  The Nvidia control panel for the graphics card only shows the two attached monitors and not the phantom one.

Unplugging one of the monitors does not remove the phantom one from the list, just the one I have unplugged

I have solved the issue with the log in screen going dark by disconnecting this monitor in the Windows settings (It is listed as monitor 1 in the settings with my actual monitors set as 2 and 3 (I can not change this numbering), so when I was logging off the other 2 monitors were going blank even though my HD monitor is set to default primary display and it was trying to display the log in screen on this phantom monitor)

The problem I have now is that if I try and enter the Bios or any out of windows settings then the screens stay blank as I can only assume it is trying to use the phantom monitor to show the boot screens.  Have you come across this before and is there a fix as the one I have seems to be only a minor one.
I think that is normal TownTalk
Those default monitors show how many dvi or vga monitor connections you have.
You may have 4 , as this is just an estimate based on my past experiences with multiple monitors listed in device manager.
It may also depend  where you have connected each monitor, if the primary is at the number one position and the secondary is at the secondary position.
which is primary and which is number two ?
Have you changed the primary to number two?
 Looking at one Windows 8 HP Pavillion 300W Power Supply (internal)
the Nvidia 640 128 uses 75W
There could be some remnants from the previous card.Intel® HD Graphics 2500
TownTalkAuthor Commented:
Sorry for the delay on replying

In the Screen resolution settings my main monitor (Default Desktop) is listed as 2 and my second monitor is listed as position 3.  Position 1 is occupied by the phantom monitor that doesn't actually exist.

I have now tried removing the card, disabling the inbuilt graphics processor and reinstalling the new card, this hasn't solved the problem.
Davis McCarnOwnerCommented:
First, go to the Desktop and do Alt-CTRL-DEL.  Choose Start the Task Manager and then More Details.  Do File -> Run New Task and in the box, type CMD <CTRL-SHIFT-ENTER> to run an elevated command prompt. In it, type:
Next, in the device manager window click View -> Show Hidden Devices
What results is a device manager with everything Windoze ever detected.  Expand the Monitors, right-click and uninstall that phantom display.  Do the same with the on-board video.
Reboot and check the display properties. Your problem should be solved.
Going on my past experiences the only way to fix this was a format/reinstall
You need to get the  primary monitor number 1 again.
Clear the cmos or registry.
Have you tried safemode?
Uninstall the drivers for the video card and restart in VGA mode of course remove the secondary monitor and make sure the primary is in the primary position, then install the original drivers for your video card off the setup disc if you have it.
The newer nvidia cards will remove all traces of the previous drivers and settings so it could be as you say a ghost in the video card.
What I would try and do is to remove all monitors and shutdown the computer
power off literally pull out the plug
take out the video card and boot it blind. then power it off put the  video card back in and plug in the primary again.
What we are trying to do is release the grip.
I'm not fully up to date with how the registry works in W8 yet.

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