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Dual monitors occasionally won't display anything after PC is idle

By MetalX
Sep 11, 2013
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  1. Hey everyone, I've been having a recent issue with my monitors and it's really been stumping me lately. I recently acquired a 2nd Yamakasi 2560x1440 monitor from South Korea (I love these things!) and while the monitors themselves are working quite well, I've been having an issue since I connected the 2nd one.

    Occasionally (maybe 25-50% of the time) when the PC has been idle for long enough that the monitors have turned off, when I come back to the PC and move the mouse or press a key on the keyboard, the monitors turn back on and I am promptly greeted with a black screen on both, however it appears that there IS a signal as the monitors turn on and remain on, however that signal is just a blank black screen. I've got both monitors beside each other, and the one on the left side is plugged directly into the dual link DVI port on the back of my master 7950 in my crossfire configuration. The right-side monitor is plugged into an active displayport to dual link DVI adapter, which also requires a USB port for power.

    When I notice this black screen effect, I also notice a small, thin blueish bar spanning the height of the right monitor, at the far right side of the screen; this bar looks about the same thickness as the side edge of an open window in Windows 8, but I've never been able to tell if that's what it is or not.
    UPDATE: Upon closer inspection of the "blue bar", I can now tell that it doesn't look quite the same as the Windows 8 side edges of a window. It does span the entire vertical length of the screen, it's about 6-10 pixels wide, fairly bright blue, and the far left or right (seems to be random as to which it is) column of pixels is a brighter blue than the rest. Also, the line isn't QUITE at the far edge of the screen; it's offset from the edge by about another 6-10 pixels.​

    When I get this black screen effect, the mouse cursor will never appear and no matter what I do, including pressing control-alt-delete, nothing else will ever appear on the screen. If I press the power button, I can see and hear my PC doing the usual process that it does when Windows goes through a normal shut-down (which is the current setting for the functionality of the power button), and then it turns off like normal. Upon restart the issue is gone, 100% of the time, until the PC is left idle again, except that the right-hand, displayport adapter monitor is not recognized by Windows upon reboot until I unplug and replug it. I'm running Windows 8 Professional, and I just freshly reinstalled Windows on a blank solid state drive within the last two weeks.

    It appears to me that Windows is still running just fine since it seems to shut down normally, and it looks almost as though the black screen is a huge window that is stretched almost fully across my monitors, with only the far right edge visible, and without any way to interact with this window. However, I also wonder if it could be an issue with the dual link display port to DVI adapter because every single time upon restart of the PC after this issue occurs, it only recognizes the left side monitor, and won't recognize the right one until I unplug the adapter from the displayport and reinsert it. Obviously I don't want to be unplugging and replugging my monitor on a daily basis so I'm wondering if anyone has heard of a similar problem or what I could possibly do about this.

    Thanks in advance everyone :)
  2. MetalX

    MetalX TechSpot Chancellor Topic Starter Posts: 1,909

    Update: I've discovered that usually the problem can be solved by unplugging and replugging the displayport adapter while the PC is on, but only if the aforementioned "blue line" is present on the right-hand screen when I move the mouse. Yesterday, I had a similar issue except that instead of turning back on and detecting the PC's video signal which is just a black screen for both of them (with blue bar on the right one), the monitors (both of them) refused to even acknowledge that there was a signal coming to them at all and wouldn't even turn their backlights on or wake from sleep mode. Even when I hooked up 2 different monitors using standard DVI-D single link or dual link cables, I still could not get any video signal to output at all, to ANY monitor.

    Turning my speakers on, I found that I could hear the Windows 8 "device connect" and "device disconnect" sounds when I unplugged or replugged either of my 27" monitors, but nothing at all was heard when attempting to switch to other monitors. This tells me that Windows IS detecting and seeing the monitors, but somehow the video signal is just not reinitializing properly after the computer turns the monitors off after idle time.

    The only solutions I've got at the moment are to set Windows to NEVER turn my monitors off, or to shut down the PC every single time I'm done with it; neither of these solutions are particularly pleasing to me. Please let me know if anyone has any advice at all, even if it's just an idea that may or may not work out. :)

    BTW my PC specs are:
    • 2500K currently at stock settings
    • 16 GB Patriot DDR3-1333
    • MSI Z68A-GD55 B3
    • 2x Radeon HD 7950 also currently at stock settings
    • 120 GB Vertex 3 (OS/main apps drive)
    • 1TB WD Blue
    • 1TB WD Black
    • 1000W Cooler Master modular PSU


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