When you connect an external monitor to your desktop or laptop, the monitor keeps flickering. There are several possible causes to this problem. To fix the problem, you can try the possible solutions in this post.
Try the following methods one by one until you find the one that fixes the dual monitor flickering problem.
Method 1: Check the hardware
Method 2: Check if it’s caused by ground loop issues
Method 3: Change monitor’s screen resolution
Method 4: Change monitor’s refresh rate
Method 5: Update graphics card drivers
Method 6: Roll back graphics card drivers
Method 1: Check the hardware
A bad cable or monitor can cause monitor flickering issues. It’s recommended you check the cable and the monitor first. Ensure they’re working properly so you can proceed to further troubleshooting steps.
Firstly, check the connecting cable.
Unplug the cable from both the monitor end and the computer end, and then replug it. Ensure the cable is inserted into the ports firmly. After that, check if the flickering issue is gone.
If possible, test with a different cable. If your second monitor stops flickering with a different cable, your current cable is the culprit, then you should replace the cable with a new one.
Secondly, check the monitor.
To verify if the current monitor is the cause, you can try a different monitor, or you can test your current monitor on a computer that you know works fine.
If you ensure both the cable and the monitor are working properly, you can proceed to other methods.
Method 2: Check if it’s caused by ground loop issues
Second monitor flickering issues can be caused by ground loop issues, particularly if you connect the monitor to a laptop. And ground loop issues can be caused by these devices:
- External devices connected to your computer.
- Using multiple power outlets.
- A low quality power supply unit.
- Electrical devices nearby such as fridges, electrical heaters, etc.
To fix the second monitor flickering issue, you can follow the troubleshooting steps below:
Disconnect devices
Disconnect all devices from your computer (e.g. external harddrives, mobile phones, etc.), and leave only the monitor connected. Then check to see if this resolves the issue.
Use the same power outlet
Connect your computer and monitor to the same power outlet (e.g. with multi-outlet power strip). Then check to see if this resolves the issue.
Unplug the power supply
If you’re using a laptop, unplug the power supply so that it runs on the battery power. Then check to see if this resolves the issue.
Disconnect nearby electrical devices
Disconnect nearby electrical devices one by one to verify if the issue is caused by electrical devices.
If Method 2 doesn’t work for you, try Method 3.
Method 3: Change monitor’s screen resolution
If the monitor’s screen resolution is not set properly, the monitor flickering issue can occur. You can check and change the monitor’s screen resolution and see if it helps. To do so:
1) Right-click on the Start menu button and select Settings.
2) Select System.
3) Select Display and then select your second monitor.
3) Scroll down to the Display resolution section. Try the resolutions one by one and see if you can find one that fixes the flickering issue.
If Method 3 doesn’t work for you, try Method 4.
Method 4: Change monitor’s refresh rate
Screen refresh rate means how many times the display updates with new images per second. Too high or too low refresh rate can cause screen flickering issues. So check your second monitor’s refresh rate and ensure it’s set properly.
Here’s how to check and change the screen refresh rate:
1) Right-click on the Start menu button and select Settings.
2) Select System.
3) Select Display and then click on the Advanced display settings link.
4) Choose Display 2, and then click on the Display adapter properties for Display 2 link.
5) Click the Monitor tab. In the Monitor Settings section, select a refresh rate that’s higher or lower than the current refresh rate you’re using.
Tip: Try the listed refresh rates one by one and see if you can find the one that resolves the issue.
6) Click Apply –> OK to save the changes.
7) Restart your computer and check to see if the problem persists.
If Method 4 doesn’t work for you, try Method 5.
Method 5: Update graphics card drivers
Outdated and faulty graphics card drivers can cause second monitor flickering issues. To fix the problem, you can try updating your graphics card driver.
Go to your graphics card manufacturer’s website, then you can download the graphics card driver easily.
After updating the driver, restart your computer and check to see if the second monitor screen flickering issue persists.
Method 6: Roll back graphics card drivers
An updated graphics card driver can cause second monitor flickering issues. To fix the problem, you can try rolling back the graphics card driver to the older version.
To do so:
1) Open Device Manager (learn how to access Device Manager).
2) Double-click on “Display adapters” to expand it, and double-click on the graphics card device.
3) Click on the Driver tab, and then click on the Roll Back Driver button to roll back the driver.
4) Once rolling back the driver, click OK to save the changes.
5) Restart your computer and check to see if the second monitor flickering issue persists.
Hopefully you find the article helpful. If you have any questions, feel free to drop a comment below. I’ll get back to you ASAP.