Hello neryslemon,
Thanks for reaching Microsoft Community. We're sorry to hear about this issue on your device. We totally how frustrating it is that your device won't connect to your monitor.
If I may ask, were you using a dock to connect to the external monitor? Were there any changes made on the system settings prior this issue happened?
This might be due to display driver issue, software conflict or corrupted system files. In the meantime, please give these methods a try and observe if issue persists or not:
Force a shut down and restart your Surface
- Press and hold down the power button until your Surface shuts down and restarts and you see the Windows logo screen (about 20 seconds), then release the power button.
Run the Surface Diagnostic Toolkit
- In the search box on the taskbar, type Surface Diagnostic Toolkit, then select it in the list of results.
If it's not already installed, you can download it from the Microsoft Store. - Follow the on-screen instructions in the Surface Diagnostic Toolkit.
Update Windows. Ensure all pending updates are installed.
- Select Check for Windows updates. Or select Start > Settings > Windows Update.
Manually install drivers and firmware for Surface
- Check what is the current OS Build of your Windows version by typing winveron the search barnear the Windows logo.
- Go to Download driver and firmware for Surface**,**choose (your Surface model) then click Download.
Choose the .msi file closest to your current OS Build and click Next.
After downloading, run and install the .msi then Restart.
Run the System File Checker in Windows
- In the search box on the taskbar, type Command Prompt, and right-click or press and hold Command Prompt (Desktop app) from the list of results. Select Run as administrator, and then selectYes.
- Type DISM.exe /Online /Cleanup-image /Restorehealth (note the space before each "/"), and then press Enter. (**Note:**This step may take a few minutes to start and up to 30 minutes to complete.)
- After you see a message that says "The operation completed successfully," type sfc /scannow (note the space between "sfc" and "/") and press Enter.
- After you see a message that says, "Verification 100% complete," type exit.
Also, see and follow the troubleshooting guide on Troubleshoot connecting Surface to a second screen.
I hope this helps. Otherwise, don't hesitate to respond to this thread if there’s anything else that needs to be addressed.
Kind regards,
StevenK