Why Are There Green Lines On My Monitor?

Seeing strange green lines on your computer monitor can be worrying.

However, in most cases, these lines are caused by simple issues that you can troubleshoot and fix yourself.

This article will explain the common causes of green lines and how to resolve them.

Why Are There Green Lines On My Monitor?

What Causes Green Lines on a Monitor?

There are a few main culprits that can cause green vertical or horizontal lines to show up on a monitor:

1. Loose Video Cable Connection

A loose video cable connection is one of the most common reasons green lines appear on a monitor.

The video cable connects your monitor to your computer. If the cable is not fully plugged in or becomes loose, it can disrupt the signal and cause visual artefacts like green lines.

Reconnecting the video cable properly will often fix the issue. Ensure both ends of the cable are securely inserted into the monitor and computer video output ports.

A faulty or damaged video cable can also cause this problem, so you may need to replace the cable if reseating it does not help.

2. Outdated or Incompatible Video Drivers

Your computer’s video card and drivers process and deliver the signal that produces the image on your monitor.

Outdated, corrupt, or incompatible video drivers can disrupt this signal, resulting in green lines or other display issues.

Updating to the latest video drivers from the manufacturer’s website will often resolve green line problems caused by driver conflicts.

Make sure the monitor and video card drivers match up – using mismatched drivers is a common cause of monitor display issues.

3. GPU/Video Card Malfunction

If the monitor displays green lines even when connected to another computer, the issue likely lies with your computer’s graphics card or GPU (graphics processing unit).

The GPU generates the video signal, so a glitch, manufacturing defect, or component failure can introduce visual artefacts on the monitor.

Unfortunately, fixing GPU issues often requires replacing the graphics card altogether.

However, you can try some troubleshooting first:

  • Update GPU drivers – new drivers may help
  • Try a different GPU video output port
  • Test the GPU in another PC if possible

If the green lines persist, a computer repair shop likely needs to replace the GPU.

4. Monitor Malfunction

Though less common, a green line is sometimes caused by a technical malfunction within the monitor.

The LCD panel, display connectors, or power supply issues can manifest as green line artefacts. Monitor malfunctions often get worse over time.

Hooking up a different monitor to your PC is the best way to test whether the problem lies with the monitor.

If the new monitor displays correctly, you likely have a faulty one that needs to be repaired or replaced.

Check for monitor warranty coverage in case of a defective LCD panel or internal component failure.

How to Fix Green Lines on a Computer Monitor

Here is a step-by-step guide to troubleshooting and fixing a monitor with green lines:

  1. Check video cable connections: Ensure the video cable between the monitor and PC is securely plugged at both ends. Reseat connections or swap in a new cable if needed.
  2. Update display drivers: Download and install the latest video drivers for your GPU/graphics card from the manufacturer’s website.
  3. Try different GPU ports: Plug the monitor video cable into other video output ports on your PC if possible.
  4. Test with another monitor: Connect a different external monitor or TV to your computer. If it displays correctly, the issue is with your original monitor.
  5. Update monitor firmware: Check the manufacturer’s website for any available firmware updates that can fix glitches.
  6. Check GPU/video card: If the green lines persist on different monitors/TVs, the graphics card or GPU may need to be replaced.
  7. Repair/replace monitor: If a different monitor works fine when connected to your PC, your original monitor likely needs professional repair or replacement.

Frequently Asked Questions

Ques 1: Why do green lines appear on my monitor?

Ans: The most common causes of green lines on a monitor are a loose video cable connection, outdated video drivers, GPU/graphics card issues, and monitor malfunctions.

The green lines indicate a disruption in the video signal.

Ques 2: How can I eliminate green lines on my monitor?

Ans: Check video cable connections, update display drivers, test your monitor with a separate device, and inspect your GPU and monitor hardware.

Reseating cables, updating drivers, or replacing faulty components like a GPU or monitor can eliminate green lines.

Ques 3: Are vertical green lines bad for a monitor?

Ans: Green lines are not inherently harmful to a monitor but indicate a problem with video signal transmission.

Vertical green line artifacts, in particular, point to a hardware issue that likely requires the replacement of a video cable, graphics card, or monitor.

Ques 4: Can a dying monitor cause green lines?

Ans: Yes, green lines can indicate a monitor is failing and may need to be repaired or replaced.

Monitor malfunctions from issues like a defective LCD panel or failing power supply can produce vertical or horizontal green lines as the display defects worsen over time.

Ques 5: Do green lines on a monitor mean GPU failure?

Ans: Not necessarily, but a GPU (graphics processing unit) failure is a common culprit for green line artifacts on both external and internal computer monitors.

If the lines persist across different monitors and video cables, then the GPU is likely the root cause.

Replacing the GPU may be required to fix the green lines permanently.


Green lines on your monitor are annoying, but simply fixable issues like loose connections or software conflicts usually cause them.

With some systematic troubleshooting of your video cable, GPU, driver software, and monitor hardware, you should be able to eliminate those frustrating green lines and get your display back to normal.

Don’t hesitate to enlist professional computer repair help if needed.


How to Fix Green Lines on Monitor – MakeUseOf

How to fix vertical lines on your computer monitor – CNET

How to Fix Vertical Green Lines on a Computer Monitor – It Still Works

What Causes Vertical Lines on Monitor and How to Fix It? – Driver Easy

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Manvendra Singh
Manvendra Singh

Hi, I am John Williams. Editor-in-chief of the website PCSynced.com. Here I write about PC technology & Guides.