If you’re noticing horizontal lines appearing on your AOC monitor, you’re not alone. This issue can range from a minor flicker to persistent lines that disrupt your viewing or work experience. Fortunately, there are several troubleshooting steps you can take to attempt to fix the problem before resorting to professional repair or replacement. This guide will explore the most common causes of horizontal lines and how to fix them.
What Causes Horizontal Lines on AOC Monitors?
Horizontal lines can appear on your monitor screen due to a variety of reasons, both hardware and software-related. Below are some of the common culprits:
- Faulty or loose video cables
- Outdated or corrupted graphics drivers
- Monitor hardware failure
- Display settings or resolution mismatch
- Interference from nearby electronic devices

Step-by-Step Troubleshooting Guide
1. Check the Cable Connections
Loose or damaged cables are a common cause of display issues. Make sure your HDMI, DisplayPort, or VGA cable is securely connected.
- Unplug and replug the cable to ensure a firm connection.
- If possible, use a different cable or port to rule out a defective component.
- Inspect the cables for any visible signs of wear or damage.
2. Update Graphics Drivers
An outdated or corrupt graphics driver can cause display issues including horizontal lines.
- Open Device Manager on your computer.
- Expand the Display adapters section.
- Right-click on your graphics card and choose Update driver.
- Follow the prompts to search automatically for updated drivers.
If the problem persists, consider downloading the latest driver directly from the GPU manufacturer’s website such as NVIDIA, AMD, or Intel.
3. Perform a Monitor Self-Test
Many AOC monitors support self-test features which help determine if the issue is with the monitor or your computer.
- Unplug the video cable from your monitor.
- The monitor should display a self-diagnostic screen with floating colored boxes or lines.
- If horizontal lines still appear during the self-test, it’s likely a hardware defect in the monitor.
4. Check Display Settings
Inappropriate screen resolution or refresh rate configurations can cause display anomalies. Make sure your display settings are compatible with your monitor’s specs.
- Right-click on the desktop and go to Display settings.
- Click on Advanced display settings.
- Ensure the refresh rate and resolution match the recommended values for your AOC model.
5. Eliminate Interference
Devices such as routers, speakers, or even power strips can emit electromagnetic interference that affects monitor performance. Try these steps:
- Move the monitor away from other electronic devices.
- Plug the monitor directly into a wall outlet rather than a power strip.

6. Test on Another Computer
To rule out a problem with your PC, try plugging the monitor into a different computer or laptop. If the lines disappear, the problem most likely lies with your original system’s GPU or software. If they persist, it’s probably the monitor itself.
7. Perform a Factory Reset
Resetting your AOC monitor to its factory settings can resolve misconfiguration issues:
- Access the monitor’s on-screen display menu using its physical buttons.
- Find the Factory Reset option and confirm.
Note: This will reset all visual settings including brightness, contrast, and color profiles.
When to Consider Professional Help
If you’ve gone through all these steps and the horizontal lines still persist, the problem may lie with the monitor’s internal components such as the LCD panel or logic board. In such a case:
- Check if your AOC monitor is still under warranty.
- Contact AOC support for an RMA (Return Merchandise Authorization).
- Consider taking it to a certified repair center if out of warranty.
Prevention Tips
To minimize the chances of future issues:
- Keep display drivers up to date.
- Maintain proper ventilation around your monitor.
- Avoid direct sunlight or moisture exposure.
- Handle cables and ports gently to avoid wear and tear.
Horizontal lines can be frustrating, but with a systematic approach, many causes can be identified and resolved. Whether it’s a simple loose cable or a deeper internal fault, understanding the symptoms is the first step toward a clear, crisp display again.