How to Run the LCD Built-in Self-Test on a Dell Laptop

If the LCD screen on a Dell laptop is experiencing any of the following symptoms, running a diagnostic test can help identify if the display issue is inherent to the LCD screen.

• Flickering
• Blurry, fuzzy, or distorted image
• Horizontal or vertical lines
• Geometric distortion or skewed image
• Distorted or fading colors
• Bright or dead pixels
• Light leak
• Image burn, bright, or black patch
• Bubbles or air pockets

If the display issue is with a Dell monitor, see the Dell knowledge base article How to Run a Diagnostic Test on a Dell Monitor.

Display or video issues can be caused due to outdated graphics drivers, hardware failure (LCD screen), or incorrect video settings on the computer.

Running a diagnostic test on the LCD screen helps identify if the issue is an inherent hardware problem with the LCD screen.

LCD Built-in Self-Test (BIST)

Dell laptops have a built-in diagnostic tool that helps determine if the screen abnormality is an inherent problem with the LCD screen of the Dell laptop, the video card (GPU), or the display settings on the computer. If you notice screen abnormalities like flickering, distortion, clarity issues, fuzzy or blurry images, horizontal or vertical lines, color fade, bubbles, it is a good practice to isolate the LCD screen by running a diagnostic test. The LCD built-in self-test can be initiated in two ways:

Method 1

1. Turn off the computer.
2. Disconnect any devices that are connected to the computer.
3. Connect the AC adapter (charger) to the computer.
4. Ensure that the LCD screen is clean (no dust particles on the surface of the screen).
5. Press and hold the D key and turn on the computer to enter LCD built-in self-test (BIST) mode. Continue to hold the D key, until you see color bars on the LCD screen.
6. The screen displays multiple color bars and changes colors to black, white, red, green, and blue.
7. Carefully inspect the screen for abnormalities.
8. Press the Esc key to exit.
9. If the screen abnormality is not present in the built-in self-test mode, see the Dell knowledge base article How to Troubleshoot Display or Video Issues on a Dell Laptop.
10. If the screen abnormality is present in the built-in self-test mode, contact Dell Technical Support for repair options available at your location.

Method 2

1. Turn off the computer.
2. Disconnect any devices that are connected to the computer.
3. Connect the AC adapter (charger) to the computer.
4. Ensure that the LCD screen is clean (no dust particles on the surface of the screen).
5. Press and hold the Fn key and turn on the computer to enter the preboot diagnostics mode. Continue to hold the Fn key, until you see the preboot diagnostic screen.
   NOTE: SupportAssist Pre-boot System Assessment or Enhanced Pre-Boot System Assessment (ePSA) diagnostic test checks the hardware and reports any hardware errors. Make a note of the error code or error message, validation code, and contact Dell Technical Support for repair options available in your location.
6. When you see the message "Do you see the color bars? Yes/No", press the N key to enter LCD built-in self-test mode.
   NOTE: If you do not respond for 30 seconds, the diagnostic test assumes your response as No and enters the LCD built-in self-test (BIST).
7. The screen displays multiple color bars and changes colors to black, white, red, green, and blue.
8. Carefully inspect the screen for abnormalities.
9. The computer restarts after the remaining tests are completed.
10. If the screen abnormality is not present in the built-in self-test mode, see the Dell knowledge base article How to Troubleshoot Display or Video Issues on a Dell Laptop.
11. If the screen abnormality is present in the built-in self-test mode, contact Dell Technical Support for repair options available at your location.

Back to top

Display Maintenance Guidelines

To learn more about best practices on handling and using a Dell laptop, see the Dell knowledge base article Best Practices for Product Use and Handling for Dell Laptops.

To learn more about general maintenance guidelines, see the Dell knowledge base article General Maintenance Guidelines For a Dell Computer.

Back to top

Safety Instructions

For displays with glossy bezels, consider the placement of the display as the bezel may cause disturbing reflections from surrounding light and bright surfaces.

To learn more about safety instructions, see the Dell knowledge base article Safety Precautions When Working with Electronic and Electrical Equipment.

For FCC notices (U.S. only) and other regulatory information, see the regulatory compliance website www.dell.com/regulatory_compliance.

Back to top

Frequently Asked Questions

Click to expand a section for more information. Alternatively, click Show all or Hide all, to expand or close all the sections simultaneously.

Back to top

Recommended Articles

Here are some recommended articles related to this topic that might be of interest to you.

• How to Run a Diagnostic Test on a Dell Monitor
• How to Troubleshoot Display or Video Issues on a Dell Laptop
• Troubleshooting Light Leakage or Light Bleeding on a Dell Monitor or Laptop LCD Screen
• How to Troubleshoot Display or Video Issues on a Dell Monitor
• Dell Display Pixel Guidelines
• How to Run a Dell Online Diagnostic Test
• How to Run a Diagnostic Test Using SupportAssist