Windows 10: Emulate monitor cable disconnect via powershell/cmd

Hello,

is there a way to make my windows think my monitor was unplugged/plugged again software side?


A little bit of background to explain why i'd want to do such a ridiculous thing:

My problem is my monitor loses signal upon windows boot.

All works fine until just before windows takes over hp startup, then my monitor goes "no video signal".

I can still wait, hear windows login, put in acc and pass by memory and have it log in...i can do pretty much everything, except i have to go by memory because i cannot see anything.

The video signal does not come back even if i wait for hours.

Nothing changes if i turn the monitor off.

Nothing changes if i power the monitor off.

But when i unplug the DVI cable, i hear the "pnp disconnect" sound.

When i plug the cable back in, i hear the "pnp connect" sound and screen starts working again.


I've tried solving the root issue, because "replug the video cable whenever i reboot my system" is not an acceptable solution for me.

Updating graphic drivers did nothing already up to date.

Uninstalling and reinstalling graphics drivers did not help.

Reimaging my windows did not help well, worked for first boot, then back to "normal".

Getting new monitor did not help.

Getting new DVI cable did not help.

Getting another extremely old monitor and using VGA to plug it in did not help worked exactly the same - signal lost upon boot.

I'm not going to buy new motherboard got integrated graphics nor willing to buy graphics card just for this.


So, is there a way i could make my system think the cable got unplugged/plugged again? Maybe some service handling the connection that could be restarted? Or some device that could be disabled/enabled? By the "pnp disconnect" sound i'm 100% positive my system immediately knows i've unplugged the cable - but how does it know?

:)

 

CMD and PowerShell

Hi Andre,

I did all items you listed.

After reboot, running CMD and powershell (admin) had the same result ("no app associated"). So I turned the feature off in taskbar settings.

Regards,

Danker

 

PowerShell instead of Commandline in Creators Update

For what I use cmd (ipconfig, ping, diskpart...) PowerShell works just fine

 

Settings using powershell/cmd?

Yes, you could use PowerShell, a BAT/CMD file or other method (I use AutoHotkey 'cos I find the syntax easier than PowerShell plus I can create GUIs with toggles/options/buttons, etc.)

As @dalchina mentions, the secret is finding the registry locations where the settings are amended. There are tools like Active Registry Monitor that will help but probably the simplest (and cheapest... it's free) is to use Sysinternals/TechNet's Process Monitor (ProcMon).

Rather than reinvent the wheel, have a look at these tutorials/videos about using Process Monitor:

• Defrag Tools: #3 - Process Monitor
• Defrag Tools: #4 - Process Monitor - Examples
• Using Process Monitor to Troubleshoot and Find Registry Hacks
  

Using your example of Win 10's Power light, the process (using ProcMon) would be:

1. Start ProcMon.
(Tip: Create a shortcut to Procmon.exe, set it to 'Run as administrator' and append -NoConnect to the target. This will start ProcMon as elevated and, more importantly, NOT monitoring.)




2. Turn off monitoring for everything except the registry, i.e. on the toolbar leave just Show Registry Activity enabled:




3. Add RegSetValue as a filter. (Perhaps easiest is to just download, unzip and import this filter: RegSetValue.zip.)

4. Open Settings and navigate to System > Display.

5. Amend window sizes so both the Settings and Procmon windows are visible/not overlapping:




6. In ProcMon, click on the Capture button (or use CTRL+E).

7. In Settings, click on the Night light toggle switch.

8. Wait a second or two then, in ProcMon, click on the Capture button (or use CTRL+E) to stop capturing.

9. Right-click on the captured RegSetValue results and choose Jump To... . This will open the Registry Editor at the keys you need to examine.

(My test showed that the process invoked a change in two registry keys:




This is because toggling the Night light switch in Settings > System > Display also toggles a setting in Settings > System > Display > Night light settings.)

Using this process you can build PowerShell, BAT/CMD, AHK scripts to implement the changes you want without even opening the Settings app.

Hope this helps...