Green Lines on Monitor: What They Mean and How to Do Green Line Test

Green Line Test

Are you seeing green lines on your computer monitor? This can be an annoying and frustrating problem that can affect your ability to use your computer effectively. The good news is that green lines on a monitor are often fixable and there are a variety of solutions available to help. 

In this article, we’ll explore the causes of green lines on a monitor and provide easy-to-follow steps to help you do Green Line Test. Whether you’re a computer expert or a beginner, you’ll find the information and solutions you need to get back to using your computer with ease.

What are Green Lines on Monitor Screen?

Green lines on a monitor are horizontal or vertical lines of green color that appear on the screen. They can appear in a single line or multiple lines, and can range from being thin to thick. Green lines can be a sign of a problem with the computer or monitor, and can affect the display and make it difficult or impossible to use the computer effectively.

The appearance of green lines on a monitor can be caused by a number of different factors. The cause of the green lines will determine the right solution, which could involve checking cable connections, updating drivers, improving ventilation to prevent overheating, or troubleshooting hardware issues.

What Causes Green Lines on a Monitor?

Green lines on a monitor can occur for several reasons, including:

  • Loose or damaged cables: The cable that connects your monitor to your computer can become loose or damaged, causing interference and display problems, such as green lines.
  • Outdated or incorrect drivers: If your monitor and computer drivers aren’t up to date or aren’t compatible, you may see green lines on the screen.
  • Overheating: If your computer or monitor gets too hot, it can cause the display to become unstable and result in green lines.
  • Hardware problems: Sometimes, a malfunctioning graphics card or other hardware component can cause green lines on the screen.

How to Perform Green Line Test and Resolve the Issue

The green line test is a simple and effective way to confirm if the green lines on your monitor are caused by a hardware or software problem. Here are the steps to perform the green line test:

Check for Hardware Problems

Use the following steps to verify if your computer’s hardware is functioning correctly:

  1. Click on the Start button.
  2. Search for Device Manager and click on the top result to launch it.
  3. Locate the device you want to check and expand its branch.
  4. Right-click on the device and select the General option from the menu.
  5. Check the status of the device in the “Device status” section.
  6. If it says “This device is operating correctly”, it means the hardware is connected to Windows 10 without any issues.

If the device is not operating correctly, you will receive an error number along with an explanation of the problem. For example, error code 22 indicates that the device has been disabled and needs to be re-enabled to resolve the issue.

Boot into Safe Mode

Safe Mode is a diagnostic mode in Windows that only loads the necessary drivers and services. To boot into Safe Mode, restart your computer and repeatedly press the F8 key until you see the Advanced Boot Options menu. From there, select Safe Mode and press Enter. If the green lines are not present in Safe Mode, it is likely a software issue.

Check for any physical damage

Inspect the monitor for any physical damage, such as cracks or scratches on the screen. If there is any physical damage, it may be the cause of the green lines.

Check for loose or damaged cables

This is another step of doing Green Line Test. Firstly, make sure the cables connecting the monitor to the computer are securely attached and not damaged. Additionally, if the cables are loose or damaged, replace them.

Update or reinstall the drivers

To fix any suspected issue with your system’s graphics driver uninstall and reinstall the graphics driver, simply follow these steps:

  1. Open the Device Manager using the Control Panel or by pressing the Windows key and the letter R to launch a Run window and then typing “devmgmt.msc”.
  2. Locate the Display Adapters section by searching for it and double-clicking on the icon.
  3. Right-click on the device for which you want to remove the driver and select “Uninstall device” from the context menu.
  4. Confirm the uninstallation by choosing the option to delete the driver software and check the “Delete the driver software” option.
  5. If necessary, also remove the driver package through the driver’s control panel by choosing the “Uninstall” option.

Update Your Motherboard BIOS to Their Latest Version

This is the standard procedure to eliminate green lines on a monitor, regardless of whether the motherboard is set to UEFI or BIOS:

  1. Firstly, update your BIOS (or UEFI) by visiting the manufacturer’s website and downloading the latest version.
  2. Secondly, after unzipping the files, copy them to an extra USB flash drive.
  3. Restart your machine and enter the BIOS / UEFI settings.
  4. You can update the BIOS / UEFI through the menus.
  5. It is advisable to back up all important data on your computer before starting the update. 
  6. Lastly, if you have a backup on a removable disk, you can retrieve your files and continue working on another computer.
  7. Additionally, it is a good idea that you make a copy of your BIOS. This can help you to recover from any problem done during the process.

Make Sure of Your Monitor Refresh Rate

Monitoring the refresh rate of a computer can help diagnose and solve problems with graphics performance. The refresh rate refers to how frequently the screen updates its image, and a slow refresh rate can result in visual anomalies, such as green lines, on the screen.

These lines indicate that the monitor is not keeping up with the latest graphics rendering commands, leading to a degraded user experience.

There are three main reasons to monitor your computer’s refresh rate:

  • First, you need to check if there are any GPU related issue which should need your attention.
  • Second, to enhance graphics performance by making sure the monitor displays updated images at a fast rate; and


You can face green line issue on your monitor due to several reasons. If you are experiencing green lines on your monitor then you can do green line test. Also you can try the solutions outlined in this article to fix the problem. If the green lines persist, it may be a hardware issue and you should seek assistance from a professional or the manufacturer.

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