If the display on your VingCard 2800 machine is very dark and difficult to read even after adjusting the lighting and contrast settings and changing the batteries, it could indicate a hardware issue with the display screen. Here are some steps you can take to diagnose further and potentially resolve the issue:

1. Check for Physical Damage: Inspect the screen for any signs of physical damage or wear that might affect its visibility.
2. Adjust Display Settings (Again): Try adjusting the display settings again to ensure they are set correctly. Sometimes, cycling through settings can unexpectedly resolve display issues.
3. Power Cycle the Machine: Turn off the VingCard 2800, wait a few minutes, and then turn it back on. This can sometimes resolve minor software glitches that might affect the display.
4. Inspect Internal Connections: If you’re comfortable with it and it’s safe to do so, check the internal connections to the display. Loose or corroded connections can cause display issues. However, be cautious, as this might void any warranty.
5. Consult the User Manual or Technical Support: Refer to the user manual for troubleshooting tips related to display issues. If the problem persists, contact VingCard’s technical support. They can provide more specific guidance based on your model and may be able to diagnose the issue remotely.
6. Seek Professional Repair: If VingCard technical support suggests the issue is with the hardware, you may need to send the unit in for repair or have a professional technician look at it.
7. Consider Environmental Factors: External factors like ambient lighting or viewing angles can sometimes affect screen visibility. Adjust these if possible.
8. Replacement: If the machine is old and repairs are not feasible or cost-effective, consider replacing the unit. Technology in access control systems evolves, and newer models might offer better functionality and reliability.

Display issues in critical systems like the VingCard 2800 should be addressed promptly to ensure the system remains functional and effective for your security needs.

For more Vingcard lock problems and troubleshooting, please check this article: Vingcard Door Lock Manual Troubleshooting: Step by Step Guide!