Forum Discussion

mattmutch's avatar
mattmutch
Active Contributor
6 years ago

Screen Resolution, Matching, Black Screen, AMD Graphics

Have just built a new workstation which I intended to run headless and use via LogMeIn only. It happens to use an AMD based graphics card. The computer was set up fine with directly connected keyboard, mouse, and monitor. Unplugged all peripherals, logged in from another computer, and got to a black screen. Nothing I did like moving the mouse or sending CTRL-ALT-DEL or changing the resolution yielded an image.

 

The spare monitor I have on hand is a 1600x900 monitor. I plugged this in and then remotely connected again. I can then connect properly, except my remote resolution maxes out at 1600x900 - both Screen Matching and manually selecting 1920x1080 (the resolution of the computer I'm sitting at) do not work with the latter being completely unavailable anyway. 

 

Somewhat anecdotally, the only other computer I've worked with with LogMeIn and an AMD Graphics card can also not remotely set a standard, full HD resolution. That one can set anything like 1600x900, 1600x1200, or 1024x768, but not 1920x1080, and THAT computer IS plugged into a 1920x1080 monitor.

 

So, I've got two AMD based computers which cannot set a standard full HD remote connection resolution for two different reasons, and I can't operate them headless because I get nothing but a black screen. I'd rather not have to waste a monitor plugging it into a remotely accessed machine, and I'd rather not be stuck at the 1600x900 of the only spare display I have. Are there any solutions for any of this?

Problem
  • Mizziness's avatar
    Mizziness
    New Contributor
    6 years ago
    mattmutch wrote:

    ...

    So, I've got two AMD based computers which cannot set a standard full HD remote connection resolution for two different reasons, and I can't operate them headless because I get nothing but a black screen. I'd rather not have to waste a monitor plugging it into a remotely accessed machine, and I'd rather not be stuck at the 1600x900 of the only spare display I have. Are there any solutions for any of this?

    mattmutch I have had this problem for several months and finally found a fix that worked for me.  Maybe it will help you! 

     

    This is the blank (solid black) screen I only ever got after upgrading my tower's graphics card:

     

     

    As you can see, HD color quality is chosen here - this was set by default.  I foundvia misclick that if you select either of the other color options, BAM!  Video returns!

     

     

    It was so simple a fix it almost made me more mad than the issue :P

     

    I hope this helps!

    • mattmutch's avatar
      mattmutch
      Active Contributor
      6 years ago

      This is interesting. I tried the resolution options but I didn't alter any color options. I'll have to try this Monday, when I'm back in the office and can physically unplug the monitor I left plugged in. But I thank you for your suggestion and will report back.

      In the meantime, if you're around, after switching to Thousands of Colors or whatever and getting a display image, can you then switch back to Millions of Colors successfully? And your graphics card, an AMD based model?

      • Mizziness's avatar
        Mizziness
        New Contributor
        6 years ago

        I'm still around!

        I was not able to switch back and have the HD color option work, no. I have an Nvidia 1080 ti card - my previous card was also Nvidia (a 960, to be exact), and all of the color options worked fine with it.

        I've confirmed this fix (at least for myself) both on MacOS Mojave and Windows 10, both completely up to date.

        As a side note, I don't ever have a monitor plugged into this tower unless I'm actively gaming on it - these screenshots were with no monitor connected at all. It's always worked just fine, including now with this fix, with no monitor attached.

  • AshC's avatar
    AshC
    Retired GoTo Contributor
    6 years ago

    Hi Matt,

    I'm afraid when there aren't any displays attached, LMI doesn't have a screen image to capture and transmit -- thus the black screen when connected remotely.  This works the same in most environments, except where a HD is capable of still creating the desktop images without a monitor. 

    • mattmutch's avatar
      mattmutch
      Active Contributor
      6 years ago

      Thanks for your reply. 

       

      What do you mean by HD in your last statement?

       

      Also, I find it curious that four other workstations on our account are connected to a single display via a VGA based KVM switch - only one is visible on the local display at a time. However, I can access any of them without the KVM switch being switched to a specific computer. Is this a product of being connected to a display, even if the display is not active? Or is it merely by virtue of the fact that a display cable is connected? Or is it that a display device is connected, even if it is not active? Will just plugging in a DisplayPort or HDMI cable make my PC accessible headlessly?

      • AshC's avatar
        AshC
        Retired GoTo Contributor
        6 years ago

        Sometimes it is as simple as plugging in the cable, but it depends on the OS behavior itself.  The display does not have to be powered on for the hard drive to create the desktop image.