How to Fix an External Monitor That Flickers or Shows Distorted Lines After Waking from Sleep on Windows 11

Summary

This guide helps you troubleshoot and resolve: How to Fix an External Monitor That Flickers or Shows Distorted Lines After Waking from Sleep on Windows 11. Follow the steps below to fix the issue.

Common Causes

External monitors connected to Windows 11 laptops sometimes flicker or display distorted lines after the computer wakes from sleep mode. This is typically caused by a mismatch in refresh rate settings, an outdated graphics driver, or Windows failing to correctly re-establish the video signal after a low-power state. Follow the steps below to resolve this issue.

Quick Fix Steps

1. Unplug the video cable from both the laptop and the monitor, then plug them back in firmly.
2. Press Windows key + P and select Duplicate or Extend to reset the display mode.
3. Restart your laptop to clear any temporary graphics glitches.

Detailed Instructions

1. Adjust the Screen Refresh Rate

An incorrect refresh rate is a common cause of flickering after waking from sleep.

1. Right-click on the desktop and select Display settings.
2. Scroll down and click Advanced display.
3. Select your external monitor from the Choose a display dropdown menu.
4. Click the dropdown next to Choose a refresh rate and select a different value (for example, switch from 60Hz to 59Hz or vice versa).
5. Check if the flickering or distorted lines have stopped.

2. Update Your Graphics Driver

Outdated or corrupted display drivers often cause signal issues when waking from sleep.

1. Right-click the Start button and select Device Manager.
2. Expand the Display adapters category.
3. Right-click your graphics adapter (e.g., Intel, NVIDIA, or AMD) and select Update driver.
4. Choose Search automatically for drivers and follow the prompts.
5. Restart your computer once the update is complete.

3. Disable Hardware Acceleration (If flickering occurs in specific apps)

If the distortion only happens in a web browser or a specific application, hardware acceleration may be the cause.

1. Open the application where the flickering occurs.
2. Go to Settings > System (or Appearance).
3. Locate the option for Use hardware acceleration when available and toggle it Off.
4. Restart the application.

Troubleshooting

Check Your Cable and Port

• Inspect the HDMI, DisplayPort, or USB-C cable for visible damage.
• Try a different cable to rule out a faulty connection.
• Plug the monitor into a different port on your laptop if one is available.
• Ensure the monitor is set to the correct input source using its physical buttons.

Adjust Power Settings

Windows may be turning off the external display to save power, causing a delay or glitch upon waking.

1. Open Settings and go to System > Power & battery.
2. Click Screen and sleep.
3. Ensure the settings for when the device is plugged in are not set to turn off the screen too quickly.

If you have tried all the steps above and the monitor still flickers or shows distorted lines, there may be a hardware fault with the laptop port or the monitor itself. You can Open a Ticket for further assistance from our Brisbane support team.

For other Windows issues, you may find these guides helpful:

• Computer running slow
• Browser not loading pages
• Applications freezing or crashing
• Blue screen of death (BSOD) - restart steps

Still Having Issues?