Experiencing a backlight issue on the display of your MacBook Pro M1 (14-inch) 2021 model can be frustrating, as it affects visibility and usability. Here’s a comprehensive guide to troubleshooting and potentially resolving the backlight issue:

1. **Check Brightness Settings**: Ensure that the brightness settings on your MacBook Pro are adjusted appropriately. Press the brightness keys on the keyboard (F1 and F2) to increase or decrease the brightness level. Sometimes, the backlight may appear dim due to low brightness settings.

2. **Restart Your MacBook**: A simple restart can sometimes resolve temporary software glitches that may be affecting the backlight. Restart your MacBook Pro and observe if the backlight issue persists after rebooting.

3. **Reset NVRAM/PRAM**: Resetting the Non-Volatile Random-Access Memory (NVRAM) or Parameter RAM (PRAM) can help reset display settings and potentially resolve backlight issues. Restart your MacBook Pro and immediately press and hold the Option, Command, P, and R keys simultaneously until you hear the startup chime for the second time.

4. **Check System Preferences**: Navigate to System Preferences > Displays and verify that the “Automatically adjust brightness” option is enabled. This setting allows your MacBook Pro to adjust the display brightness based on ambient light conditions. Disabling or enabling this option may help resolve backlight issues.

5. **Update macOS**: Ensure that your MacBook Pro is running the latest version of macOS by checking for updates in System Preferences > Software Update. Apple frequently releases updates to address bugs and improve system stability, which could potentially resolve backlight issues.

6. **Perform Apple Diagnostics**: Use Apple Diagnostics to check for hardware issues related to the display backlight. Restart your MacBook Pro and immediately press and hold the D key until the diagnostics screen appears. Follow the on-screen instructions to run the diagnostic tests and identify any hardware issues.

7. **Seek Professional Assistance**: If the backlight issue persists despite trying the above steps, it’s advisable to contact Apple Support or visit an authorized service provider for further assistance. The problem may be indicative of a hardware malfunction that requires professional diagnosis and repair.

By following these steps, you can systematically troubleshoot and potentially resolve backlight issues on your MacBook Pro M1 (14-inch) 2021 model, ensuring optimal visibility and usability of the display.