Have you ever wondered why your LED screen sometimes exhibits different brightness levels across various sections?
When you notice some areas appearing brighter or dimmer than others, it indicates an imbalance that can affect the overall viewing experience.
These inconsistencies in brightness not only affect the aesthetic appeal of the display but can also lead to suboptimal performance and viewer dissatisfaction.
In this guide, we will walk you through the essential steps to diagnose and fix the issue of different brightness levels on your LED display using NovaLCT. You can use the same rule for other similar LED software.
In This Article
What is Different Brightness in LED Displays?
Different brightness in an LED display refers to the inconsistency in the luminance levels across different sections of the screen, whether it is an indoor small-pixel LED screen or an outdoor advertising LED video wall.
As shown in the following image, both displays have different degrees of brightness difference.
Why Do You Need to Fix the Issue of Different Brightness?
Fixing discrepancies in LED screen brightness is crucial for maintaining a high-quality visual presentation.
- Visual Appeal: Uniform brightness ensures that the display looks aesthetically pleasing and professional.
- Readability: Inconsistent brightness can make it difficult to read text or view images clearly.
- Lifespan: Consistent brightness helps in prolonging the lifespan of the LED modules.
- User Experience: A consistent display enhances the viewer’s experience, making content more engaging and impactful.
Possible Reasons for Different Brightness
There are several potential causes for different brightness in LED displays, including:
- Different Brightness Modes: Some cabinets may use grayscale mode while others use contrast mode.
- Different RCFGX Files: Cabinets might not have the same configuration files (RCFGX files), leading to discrepancies.
- Different Firmware: The LED receiving cards might have different firmware versions.
- Calibration Coefficient: Some cabinets may have calibration coefficients enabled while others do not.
- Different Power Supply: Variations in power supply output can cause brightness inconsistencies.
- Multiple Batches of Modules: Using LED modules from different manufacturing batches can result in brightness differences.
How to Resolve the Issue?
Let’s delve deeper into each of the potential causes:
1. Different Brightness Modes
LED displays can operate in various brightness modes. We need to ensure that all receiving cards are set to the same brightness value. First, log in to NovaLCT as an advanced user using the password “admin”, then click “Brightness” to pop up the interface of brightness adjustment. Here we need to adjust the brightness settings manually.
Then select a consistent working mode (Grayscale or Contrast) and ensure all cards share the same gamma value. After that, click “Save to HW” to save these settings to the hardware to maintain uniformity. For detailed guidance, you can check this guide: LED Screen Brightness Adjustment with NovaLCT.
2. Different RCFGX Files
Different RCFGX files can cause significant brightness discrepancies due to varying parameters. Each cabinet may be using different RCFGX configuration files.
In this situation, we can use NovaLCT to check the parameters of the cabinets to ensure they match.
For example, as in the following image, when we check the receiver card parameter of the two cabinets, they have different parameter values of the RCFGX file. The refresh rate of cabinet 2 is 3840hz, and cabinet 1 is 1920Hz, also they have different shift clock frequencies, cabinet 1 has 15.6 frequencies and cabinet 2 has 20.8 shift clock frequency, so it will cause different brightness efficiency, which you can see at the bottom of the interface, cabinet 1 is 71.99%, and cabinet 2 is 52.38%.
If discrepancies are found, the first method is just to read back the correct parameter from a normal receiving card and then send the parameter to the abnormal receiver cards. The second method is that we can load the original RCFGX file and then send it to all receiver cards.
In addition, you can download our preset Novastar RCFGX files too if you dont have one.
After syncing the files, save the settings and restart the power of the screen to verify uniform brightness across all sections.
3. Different Firmware
Different firmware versions can cause receiving cards to output varying brightness levels. So we need to ensure all receiving cards are running the same firmware.
You can click the “Setting” in the main interface of NovaLCT, then click “Hardware Information” from the drop list to navigate to the window to check the firmware version of all receiver cards. Here is an example that shows there are 3 firmware versions, you can see that one version is 4.4.4.0, one is 4.4.3.0, and another is 4.4.4.6.
To fix this:
- Download Correct Firmware: Obtain the correct firmware from the Novastar official website or the LED display manufacturer.
- Upgrade Firmware: Upgrade the firmware on the receiving cards with brightness issues.
For a comprehensive upgrade process, reference the Novastar Firmware Upgrade Step-by-Step Guide.
4: Calibration Coefficient Issues
Calibration coefficients stored in the receiving cards can greatly influence brightness uniformity across cabinets. If some cabinets have calibration enabled while others do not.
If we check the following pictures we will find that the cabinet with the red circle marked, its uniformity is worse than others, and the other cabinet’s uniformity is better. This suggests that the calibration coefficient needs to be checked.
For this situation, we can click “Tools” in the main interface of NovaLCT, then select “Calibration” from the dropdown menu to open the “Screen Calibration” window. Here you can enable or disable calibration.
If a cabinet still lacks calibration after enabling it, the receiving card might not have the calibration coefficient. In this case, you’ll need to upload or reload the calibration database using NovaLCT.
If you don’t have the database, you may need to recapture it or contact the LED manufacturer for the correct calibration coefficients. Alternatively, you can manually adjust the cabinet’s calibration settings. Initially, manually turn on the calibration for the cabinets, check for any without the calibration coefficient, and reload it.
5: Different Power Supply
Inconsistent power supply output can lead to brightness differences. To address this:
- Test Voltage Output: Use a multimeter to test the voltage output of the power supplies.
- Ensure Consistency: Ensure all power supplies have the same current and voltage output. It is advisable to use power supplies of the same brand and model.
Please note: Avoid mixing power supplies with different specifications. For example, don’t use 300W 5V 60A power supplies work together with 200W 5V 40A power supplies.
6: Multiple Batches of Modules
Using LED display modules from different manufacturing batches can cause brightness inconsistencies
What is “multiple batches”? It means the lamp or the modules are manufactured at different times, and the LED lamp has a different wavelength and brightness, which will cause the screen to look different.
Let’s examine the two LED modules in the images below. The left module appears bright, while the right one looks dimmer. If we attempt to install them together as a single screen, it will result in noticeable brightness differences.
To mitigate this, we can Click the drop item “Multi-batch Adjustment” from the “Tools” in the main interface of NovaLCT. In the new pop-up interface, we process using Manual Adjustment or Apply Adjustment File.
it is worth noting that, for the issue of multiple batches, we can enhance the brightness to make the LED modules appear as similar as possible, but it may not be completely resolved.
To Sum up
If you encounter irregular brightness, remember to follow the outlined troubleshooting steps carefully. In this post, we have learned the basic concept, the cause, and the corresponding solution to the different brightness issues. For any problems, you can contact us at any time for tech support. For more LED display tutorials, check here.
Userful Resource
NovaLCT Software
In addition, You can click the following link to get the latest NovaLCT version if required for further brightness settings.
Firmware Download