I bought a new external monitor recently and have had the issue of an intermittent display signal

Disabling the monitor in device manager fixes the issue and the monitor works fine when disabled so it’s highly likely its some weird software issue but I’d like to find a proper fix for it

I am able to get it to have constant display signal by chance sometimes without disabling the display in device manager but turning off the external display brings back the issue when I turn it back on and it reconnects

OS: Windows 11

Display: Lenovo G27QC-30 with Lenovo’s drivers installed *have tried with Microsoft drivers and run into the same issue

Have already tried uninstalling and reinstalling monitor on device manager and reinstalling drivers and that hasn’t fixed the issue

Also have already tried using display driver uninstaller to clean install graphics drivers

Edit:

the events tab in windows device manager for the monitor properties does show this error sometimes:

Device not started (monitor)

Device DISPLAY\LEN66F4\5&3287afbc&1&UID4352 had a problem starting.

Driver Name: oem64.inf Class Guid: {4d36e96e-e325-11ce-bfc1-08002be10318} Service: monitor Lower Filters: Upper Filters: Problem: 0x0 Problem Status: 0xC00000E5

Edit 2:

The monitor will work fine once if i restart my laptop but disabling and re=enabling in device manager causes the problem

  • @x4740NOPEnglish
    1•29 days ago

    Ok so setting it to limited range appears to have been a fluke because my log of further troubleshooting makes it evident.

    Below i am pasting a text log of further troubleshooting tests i did, it does seem to suggest a faulty HDMI cable, Maybe the second HDMI cable i used to test twice also was faulty

    i’m going to try and see if i can find another HDMI cable to test to see if that gives me any more information

    but I’m wondering why disabling the monitor in device manager stops the issue if it is a faulty HDMI cable

    Monitor resolution test:

PC Resolutions:

800x600:

144hz, 8bpc, Full Dynamic Range: Working at current time
*does not scale to full screen size and has black borders
60HZ,  8bpc, Full Dynamic Range: Working at current time
*With this one monitor or windows or gpu scales to the full screen size
60HZ,  10bpc, Full Dynamic Range: Working at current time
*monitor or windows or gpu scales to the full screen size
60HZ,  12bpc, Full Dynamic Range: Working at current timr
*monitor or windows scales to the full screen size

1024x768:

144hz, 8bpc, Full Dynamic Range: Working at current time
*Does not scale to full screen size

60Hz, 12bpc, Full Dynamic Range: Working at current time
* Scales to full screen size

1152x864:

144hz, 8bpc, Full Dyanimc Range: Working at current time
*Does not scale to full screen size

========

Later Steps:

2560x1440 at 12bpc 60hz full dynamic range works, so does 144hz 8bpc but this is after going through various resolutions in increasing length as documented in this text document

turning monitor off and on at this point in time does not reintroduce issue

next step is unplugging and re-plugging hdmi cable

re-plugging hdmi cable after approximatly 30 seconds, this reintroduces issue, changing to limited in nvidia control panel does not fix this

changing to 800x600 pc resolution after unplugging and replugging hdmi cable with nvidia control panel set at 144hz, 8bpc and limited dynamic range does not fix issue

then changing refresh rate to 60hz does not fix issue

setting to 1440x2560 before rebooting to see if rebooting does something

after laptop the nvidia control panel resolution was at 800x600 and the issue wasnt there but changed to 1440x2560 at 144hz 8bpc and issue started

disabling the monitor at this point in time in the device manager still fixes the problem (but breaks windows nightlight from working on external monitor as i have personally noticed when first trying to use windows nightlight after disabling the monitor in the device manager)

setting to 60hz, 8bpc 800x600 resolution

enabled in device manager, monitor blanks once but issue goes away

going to unplug and re-plug cable

re-plugged hdmi cable after 30 seconds, monitor blanks once but is stable and issue is gone

noted that output dynamic range in nvidia control panel is still set to limited

going to set to full dynamic range

at 8bpc, 60hz 800x600 at full dynamic resolution issue does not present itself

going to unplug and re-plug cable while the display resolution settings remain the same in nvidia control panel

plugging in cable after aproximatly 30 seconds, monitor blanks once but issue does not present itself
    • @[email protected]
      1•29 days ago

      Only reason I can think that disabling the monitor in the Device Manager is that it disabled freesync or HDR or stops windows trying to send CEC power saving commands or whatever.
      I have no idea why it’s a fix, but it clearly stopping windows from trying to do something which causes the screen to flash.

      I would be surprised if changing between limited and full-range fixed it. That’s a hangover from old broadcast standards. It doesn’t change the data rates.

      It seems like it’s working at lower data rates?
      So 1440p60 is working but 1440p144 isn’t?
      Which points to an HDMI cable issue, a GPU issue or a GPU driver issue (and I mention GPU/Driver because of freesync)