- Test alternative connection methods, such as an HDMI or VGA cable, to see whether the display is functioning correctly.
- Check the power connection to the external monitor.
- Check whether the cable is correctly and securely connected to the monitor.
- Perform a system restore to restore the computer to a prior, stable configuration in which it functioned correctly.
- Check whether the monitor is still supported by the operating system. If not, the driver must be updated.
- Check the Windows display settings.
- Check if the update is conflicting with the graphics card driver.
- Disable Fast Start to see if the external monitor will start to display correctly.
- Inspect the external monitor to ensure that it is functioning correctly.