LED Screen Brightness Problem – Helpful Guidance to Solve it!

When we use LED displays, there is sometimes a problem – different LED screen brightness on the same LED screen, which will affect the visual experience, and weaken our promotional effect. Today, we will discuss the reasons for this phenomenon, and methods to tackle it in a quick and effective manner!

1.Trouble-shoot Different LED Screen Brightness

As the picture shows below, we have two obvious brightness problems here – one picture shows that the brightness of the left part is obviously different from the right part, and the other picture reveals that some LED cabinets on the screen show different brightness. 

We may encounter these two situations more often, therefore, discussing how to troubleshoot them is especially important.

led display brightness

Here we list six potential reasons below, which is necessary for you to know them if you want to have the ability to deal with this problem by yourselves quickly and efficiently!

Now, let us begin!

2.1 Different brightness mode:

Here is the brightness adjustment interface of NovaLCT. As you can see, if you want to adjust brightness, there are two points: brightness level, and brightness information including grayscale level and contrast level.

LED brightness adjustment

It is obvious that the meaning of brightness level, but how do the other two elements influence LED screen brightness?

Actually, the software arthrogram decides these two elements will have different impacts on the final brightness, meaning if you choose one of them as a priority, the final effect will also have differences.

Here is a matter that need attention: if you have already adjusted the right brightness information, please remember to click the button “save to HW”, this means the information will be sent to receiving card and stored, so you do not have to adjust the parameters again after you restart the LED display screen.

OK, now we can turn to the next part.

2.2 Different RCFGX file:

Sometimes we can solve the different LED display brightness by reading back the rcfgx file from the cabinet which we want to keep the same, and then send the file to the LED cabinet that we want to change.

Of course, you can send the file to all screens, which will uniform their brightness, too. However, if you lost the file, just ask your LED display supplier to offer you a new one, or you can ask Novastar engineer for help. But normally, the prior way will be more effective.

Why Will RCFGX file Influence Brightness Efficiency?

Now, maybe you have a question: why will rcfgx file influence brightness efficiency? First of all, we have to know the value of brightness efficiency is decided by our driving IC.

If we adjust one of the values of refresh rate, grayscale, or others, the values will affect the values of other elements including brightness efficiency as the ability of a driving IC is limited.

That means if you improve one value, then the potentials for other parameters will be influenced.

In a word, different values will have interaction with other values, that is why different values in rcfgx files will cause different brightness efficiency even the physical factors are the same such as LED module type and pixel pitch.

2.3 Different firmware:

If there are some LED display cabinets with different firmware, we may get different LED screen brightness because different firmware will cause different output methods of receiving cards.

Generally, there are four ways for you to get the right firmware. First, you can find the correct one by yourself.

Second, you can update it directly.

Third, you can turn to Novastar engineers for help.

Fourth, you can ask your supplier for help.

Generally speaking, we recommend the fourth one, because sometimes customers apply customized versions, so only suppliers know the details.

However, please never update it directly if you have had the customized version, just ask for help from your LED screen suppliers.

novalct brightness

2.4 Power supply problem:

How does power supply influence LED display brightness? Sometimes the output is not enough, which will cause a weaker driver current for part of the LED display screen. Thus, this part may show different brightness from others.

Therefore, what are the measurements to solve it? You can go to check the power supply output to see whether it is correct based on the values your suppliers providing to you.

2.5 Multiple LED module batches:

As you know, different LED module batches may be produced by different raw materials, thus, the brightness of masks, the matt effect all may have discrepancies.

As a result, you will find some LED display modules are darker or brighter than others even they are not powered on.

To deal with this, you can turn to NovaLCT , and here we have a button “multiple-batch adjustment” to tackle this problem.

If you encounter some questions during the process, you can turn to the engineers for guidance.

2.6 Out of sync calibration coefficient

When some LED cabinets have turned on calibration coefficients but some are not, there will be inconsistent brightness happens on the same screen.

led screens brightness

The reasons may be that receiving cards lost their calibration coefficients, or the receiving card has been replaced, or the receiving cards don’t turn on calibration.

Now, we have discussed 6 methods for you to locate, and solve different LED display screen brightness. Let us do a summary.

a. Different brightness mode. We have two parts in this sector that will influence the final brightness effect, one is brightness level, and the other is brightness information – contrast and grayscale.

Because contrast and grayscale adjustment will have different impact on the brightness level, so make sure you know the differences.

b. Different RCGFX file. As the capability of driver IC is limited, when you adjust the values of one of the elements such as grayscale and refresh rate, the final brightness brightness efficiency will be different.

That is why even physical factors of LED cabinets are the same, sometimes the brightness will have disparity. Try to replace the wrong rcgfx file with the right one to unify the whole screen brightness! 

Generally speaking, we recommend that you can ask your suppliers for that file.

c. Different firmware. Different firmware will have different output method of receiving card. Please be notified if your screen applies customized one, it is recommended that you can turn to suppliers for the right version, and never update by yourselves directly.

d. Power supply. The insufficient current may cause less brightness than other part, and that is why we should check power supply.

You can ask your suppliers for the right values and then check it by yourselves.

e. Multiple LED module batches. Different raw materials will have different effect on LED display modules. For example, some modules will brighter than other batches even not powered on.

Under this situation, you can turn to find solutions from technicians, and try to solve it by the functions “multi-batches adjustment” on software.

f. Out of sync calibration coefficient. The reasons may be that receiving cards lost its calibration coefficients, or the receiving card has been replaced, or the receiving cards don’t turn on calibration.

To tackle this, you can turn to technicians for guidance.

2. Review

In this sector, I want to bring you to review some knowledge points we have learned in the previous posts. They are all important for you to become an LED display expert and will be helpful if you need to operate LED displays by yourself.

2.1 LED Black Screen

Before we finish the article today, let us review what we have learned in the last article LED black screen. There are two situations here: whole LED screen blackout and part of the screen blackout. For each situation, we have corresponding methods to deal with.

For the full black LED display, please check the red indicator light of receiving card at first to make sure that it is powering on. If yes, go to check other points according to conditions of green indicator lights such as Ethernet cable and receiving card files.

For the part of LED screen black, there are three levels including LED module level, LED cabinet level, and output port level. The problem may come from HUB board, flat cable, power supply, Ethernet cable, and so on. Just check them under guidance.

2.2 Novastar NovaLCT Screen Configuration

In this article NovaLCT Screen Configuration, we talked about how to configure NovaLCT from four aspects: graphics card settings, sending card settings, receiving card settings, and screen connection.

(1) For the graphics card configuration, there are displaying modes and display settings for you to choose from. Please make sure the steps that can enable your LED display boards displayed pixel-by-pixel.

(2) For the sending card setting, fill in the right video resolution, resolution and refresh rate.

(3) For the receiving card configuration, you can load in the parameters from the rcfg file. But if you do not have such file, try to read back the parameters.

(4) For the LED display connection, please fill in the right information such as the quantity of screen, columns, and rows of receiving cards, and so on. Please notify there are two very useful functions – “Enable Mapping” and “Detect Communication Status.”

It is simple if you can follow this sequence to complete the configuration. However, there are still many details for you to notice. So, just read this article again if your memory has some blur.

2.3 Color Distortion

In this essay, we discussed LED display color distortion – why does LED display board go cyan. The main reason are overheat, but why will the screen go cyan, but not other colors?

To explain this, we talked about output efficiency of brightness of different colors under a given temperature, and discovered one truth – the losses of the brightness of the three primaries are different, and the red light will lose the most.

That means, the ratio of red light will be less, thus we get cyan finally.

Then, we give three assumptive aspects to deal with this problem – peak current, output efficiency of brightness, and brightness percentage.

For more details, just click full color LED display screen to read more!

3. Conclusions

Today, we talked about a common problem – different LED screen brightness, and the reasons for it, and how to solve it. We listed six potential reasons and the corresponding methods to deal with. If you can check and do it under the guidance, we believe you can deal with the brightness problem quickly and precisely! For any more useful information about LED display and LED display control systems, please turn to our LED FAQ page!