You may someimes turn on your Samsung TV and find that the screen is dark or dim, even though the sound works fine. This could indicate that your TV has a broken backlight, a common problem for LED TVs.
A backlight is a set of LED strips illuminating the screen from behind, creating the bright and colorful images you see. When one or more of these LEDs fail, the screen can become dark or uneven, affecting the picture quality and viewing experience.
Fixing a Samsung TV with a broken backlight is not as complicated as it sounds. You can do it yourself with some essential tools and patience. So today, we will see how to fix a Samsung TV with a broken backlight.
I will explain the underlying factors and symptoms of backlight problems and how to prevent them from happening again. Just make sure you are following this guide in order to restore your Samsung TV to its original glory and enjoy your favorite shows and movies in high definition.
What causes backlight problems on Samsung TVs?
There are several possible causes of backlight problems on Samsung TVs, which may vary depending on the fault.
Faulty LED strips
The most common cause of backlight problems is when one or more LED strips fail or burn out. This can happen due to age, power surges, overheating, moisture, or physical damage.
When this happens, the LED strip will stop emitting light, creating a dark spot or band on the screen. The screen can become partially or entirely opaque depending on how many LEDs are affected.
Faulty power supply board
The power supply board is the component that provides the voltage and current to the LED strips. If the power supply board is defective or damaged, it can cause the LED strips to receive insufficient or excessive power, resulting in flickering, dimming, or burning of the LEDs. The power supply board can also fail to turn on the LED strips, resulting in a black screen with no backlight.
Faulty main board
The main board is the component that controls the signal and data processing of the TV. It also communicates with the power supply board and the LED strips.
If the main board is faulty or damaged, the LED strips can malfunction or not receive the correct commands, resulting in backlight problems. The main board can also prevent the TV from turning on or displaying any image, resulting in a black screen with no backlight.
Faulty T-con board
The T-con board is the component that transfers the image data from the main board to the LCD panel.
It also controls the timing and synchronization of the LED strips. If the T-con board is faulty or damaged, it can cause the LED strips to display the wrong colors, brightness, or contrast, resulting in backlight problems. The T-con board can also cause the TV to display a distorted or scrambled image or no image at all, resulting in a black screen with no backlight.
How do you diagnose backlight problems on Samsung TVs?
Before fixing a Samsung TV with a broken backlight, you must diagnose the problem and identify the faulty component. You will need a multimeter, a screwdriver, and a flashlight to do this. Here are the steps to diagnose backlight problems on Samsung TV:
Step 1: Turn off and unplug your Samsung TV from the power outlet. Wait a few minutes to let the TV cool down and discharge residual power.
Step 2: Take off the back cover from your Samsung TV by unscrewing the screws around the edges. Be careful not to damage any wires or connectors inside the TV. You may need a flathead screwdriver to pry open the cover gently.
Step 3: Locate the power supply board, the main board, the T-con board, and the LED strips inside the TV. The power supply board is usually the most prominent, with several capacitors and transformers.
The main board typically has several inputs and outputs, such as HDMI, USB, and antenna. The T-con board is usually connected to the LCD panel via a ribbon cable. The LED strips are typically attached to the metal frame behind the LCD panel and have wires connecting to the power supply board or the main board.
Step 4: Set your multimeter to DC voltage mode and click the black probe to a metal ground point on the TV chassis. Use the red probe to test the voltage output of the power supply board.
You should see a label on the board that indicates each connector’s voltage and current ratings. For example, you may see a label that says “LED+,” “LED-,” and “12V”.
This means that the connector provides 12 volts to the LED strips. Test the voltage of each connector and compare it to the label. If the voltage is too low or too high, or if there is no voltage, the power supply board is faulty and needs to be replaced.
Step 5: If the power supply board is working fine, test the voltage output of the main board. You should see a label on the board that indicates each connector’s voltage and current ratings. For example, you may see a label that says “BL_ON,” BL_PWM,” and “3.3V”.
This means that the connector provides 3.3 volts to the LED strips and controls the brightness of the backlight on and off. Test the voltage of each connector and compare it to the label. If the voltage is too low or too high, or if there is no voltage, the main board is faulty and needs to be replaced.
Step 6: If the main board is working fine, test the signal output of the T-con board. You should see a label on the board that indicates each connector’s signal and data ratings. For example, you may see a label that says “LVDS,” VCOM,” and “VGH.”
This means that the connector provides the image data, the standard voltage, and the gate high voltage to the LCD panel. Test the signal of each connector using an oscilloscope or a logic analyzer. If the signal is distorted, corrupted, or missing, the T-con board is faulty and needs to be replaced.
Step 7: Test the LED strips to see if the T-con board works fine. You must remove the LCD panel from the metal frame to access the LED strips. I advise you to be very careful to avoid causing any harm to the LCD panel or the cable made of ribbon that provides connectivity to the T-con board.
You may need a suction cup or a plastic card to lift the LCD panel gently. Once you have removed the LCD panel, you will see the LED strips behind it. Each LED strip has positive and negative wires connecting to the power supply board or the main board. Disconnect the cables from the board and test the voltage of each LED strip using your multimeter.
You should see a label on the LED strip that indicates each LED’s voltage and current ratings. For example, you may see a label that says “6V” and “0.5A”. This means the LED strip requires 6 volts and 0.5 amps to light up. Test the voltage of each LED strip and compare it to the label. If the voltage is too low or too high, or if there is no voltage, the LED strip is faulty and needs to be replaced.
How do you fix a Samsung TV with a broken backlight?
Once you have diagnosed the problem and identified the faulty component, you can fix the Samsung TV with the broken backlight. Depending on availability and price, you must order a replacement part online or from a local store.
You will also need a soldering iron, a soldering wire, a desoldering pump, and a heat gun if you need to solder or desolder any cables or connectors.
Step 1: Turn off and unplug your Samsung TV from the power outlet. Wait a few minutes to let the TV cool down and discharge residual power.
Step 2: Take off the rear cover of your Samsung TV by unscrewing the screws around the edges. Be careful not to damage any wires or connectors inside the TV. You may need a flathead screwdriver to pry open the cover gently.
Step 3: Locate the faulty component inside the TV. Depending on your diagnosis, it could be the power supply board, the main board, the T-con board, or the LED strip. Disconnect any wires or connectors that attach the component to the TV.
You may need a soldering iron and a desoldering pump to remove any solder joints. Be careful not to damage any other components or wires nearby.
Step 4: Replace the faulty component with the new one. Ensure that the new component matches the specifications and dimensions of the old one. Connect any wires or connectors that attach the element to the TV.
You may need a soldering iron and a soldering wire to create any solder joints. Be careful not to make any short circuits or cold solder joints.
Step 5: Reassemble the TV by putting the back cover back on and screwing the screws around the edges. Plug the TV back into the power outlet and turn it on. Check if the backlight problem is fixed and the picture quality is restored. If not, you may need to
Step 6: Reassemble the TV by putting the back cover back on and screwing the screws around the edges. Plug the TV back into the power outlet and turn it on. Check whether the backlight problem is fixed and the picture quality is restored.
If not, you may need to repeat the diagnosis and repair process with another component or consult a professional technician for help.
Step 7: Enjoy your Samsung TV with a working backlight. You have successfully fixed the Samsung TV with a broken backlight by yourself.
You can also take some preventive measures to avoid backlight problems in the future, such as using a surge protector, adjusting the backlight settings, cleaning the dust, and preventing physical impacts.
Conclusion
So you have learned and understand how to fix a Samsung TV with a broken backlight in very simple and direct steps. Also, I have explained the causes and symptoms of backlight problems and how to diagnose them with a multimeter and a flashlight.
Make sure you follow this guide so that you can save money and time by repairing your Samsung TV with a broken backlight at home. If you are not confident or comfortable opening your TV and replacing components, you should seek professional assistance.