Resolution on a laptop was accidentally set to a really low value. When the laptop was woken up from sleep mode, screen was completely black. I realized it wasn't displaying because it couldn't display when the resolution is set too low. So hooked up an external monitor and there was my desktop screen. The problem is that for some reason it won't let me switch my laptop screen back to its designation as the default monitor. It only outputs the data to the external display. In the Display control panel, the external display is designated as monitor #1, labeled as Generic PnP monitor. the laptop screen is monitor #2, default monitor(which is completely black, receiving no signal). It won't let me increase the resolution on monitor #2 so that the laptop screen can receive a signal again.
try holding down the function key ( usually with the [fn] label )... then press the F4 key (or a key with the screen icon [=] ). This will toggle the display function to cycle from main screen... to external... to both... and back.
I'm trying that. But the laptop screen remains completely black. The laptop screen, which is monitor #2, has its resolution set to 800 x 600. This resolution is way too low but for some reason the slider bar is locked and won't let me move it up, even when I enable monitor #2. I think its trying to output the data to the laptop screen when i press f4, but sees that the resolution is set too low, and so can't do it. But why won't it let me change the resolution?
This is exactly the reason I'm glad to know THIS exists: http://www.displaylink.com/index.html Or, this: http://www.evga.com/articles/409.asp
I remember reading that in Vista restore points are created periodically by default. I have not changed the default settings but I go to see what my nearest restore point is, and I find that none have been created.
OK, let me see if I can help. First, when the resolution was accidentally lowered, did the screen immediately go black? If not, the the lower resolution is not IMO the cause of your problem. In fact, it has been my experience that when you change the resolution of your monitor Windows changes the resolution and a new window pops-up stating: "Your desktop has been reconfigured do you want to save the settings" If you do not click yes within the alloted time the resolution resets to the previous resolution. The mere fact that you could/would see this window obviously means that your monitor is capable of displaying at that resolution. It may not be a great resolution setting, but nevertheless the monitor will display using that setting. I would think that if you attempted to have your laptop display at an impossible resolution (I'm not even certain that situation could exist) it would automatically reset to the prior resolution because you did not confirm your desire to save the new resolution (because the screen was black and you couldn't see the pop-up window). I believe something else is the problem. Is it possible there has been an LCD failure?
Wareco, I had Vista do the exact same thing on my laptop with an external monitor. I had to unplug the external monitor, then play with the settings to get it to do what I wanted, but I finally prevailed.
Have you tried starting your laptop in 'safe mode' - which should load up with default graphic settings. Does Vista have 'safe mode' ?
Nine times out of ten if that's when your display stops, it's simply because your display settings are set to something that your monitor can't handle. Depending on what it's not supporting, some monitors respond by going black ... others just go "crazy" displaying unintelligible gibberish. If that's the problem, it's fairly easy to fix. First things first ... let's get you a bootable system. Boot in safe mode - press F8 when the Windows loader presents you with the 30 second list of choices, and then select "Safe Mode" as your boot option. Right click on the desktop and click Properties, and then on the Settings tab. Now click and drag the Screen Resolution slider to the far left ... you want the smallest settings that your screen will support. Typically that'll be 640x480, or 800x600. Also change the Color Quality dropdown to 256 colors, or whatever is lowest. (You probably don't need to go as low as 16 colors, if that's presented as an option.) Now, click on the Advanced button, and then the Monitor tab of the resulting dialog box. Change the Screen refresh rate to 60 Hertz. OK your way back out, and reboot your machine. If these setting were the source of the problem, it should now be able to boot normally. You may not like the screen settings, but at least you now have a place to start. "Start experimenting with the settings to see what does, and does not, work with your monitor."If the display is still blank or gibberish, the my recommendation is to once again boot into Safe Mode, possibly Safe Mode with networking, and update your video display drivers. It's likely that they are incorrect or otherwise broken. http://ask-leo.com/why_does_my_screen_go_black_after_the_windows_screen_when_i_boot.html