An LED backlight fails when the LEDs have damaged the screen’s pixels. The affected LEDs will still conduct electricity, but they won’t produce light and will result in dark spots on the screen. In some cases, the backlight may be a result of a power supply failure, the driver circuit or the LED itself. Occasionally, the power supply will fail, which prevents the LEDs from turning on. In other cases, the power supply may be insufficient or the LEDs are burned out.
LED backlight circuitry damage can cause the LED strips to move out of place. A power surge can also damage the electronic components of the regulator circuit. If power gets to the LCD panel, the LEDs won’t get enough voltage. A single LED strip that has a defect can lead to an open circuit, resulting in a dim screen. Fortunately, these issues are often fixable, and can be easily repaired.
In addition to electrical traces on the circuit board, backlight circuit failure can also be caused by water damage. Water can break the electrical path to the connector, which can lead to a short. A defective LED will block the connection between the LCD panel and the LEDs. Another reason for LED backlight failure is damaged electrical traces on the circuit board. When these conductive traces are damaged, the LEDs will not receive power.
If your TV is not producing any light, then the problem is most likely with the backlight inverter. To determine the exact fault, use a bright flashlight and hold it one to two inches away from the TV screen. If you can’t see the image, try changing the HDMI input and seeing if you can get a signal. If you still cannot see anything on the screen, replace the power supply board.
The most common problem with a TV backlight is a burning out LED. It should look very dark to indicate a burning issue. If the LED is burned out, it should be replaced with a new strip. If the backlight is still working but the image is too dim, there may be another cause. An issue with the main processor board of the television can also result in a dead backlight. Depending on the model, a new panel or processor board could be necessary. If you are not confident with your repair skills, you can take it to an authorized service center.
To determine if your TV backlight is broken, you can use a flashlight to look into the backlight. A TV backlight can look incredibly dim if the screen is overly dark. The first thing to do is turn off all of the lights in the room. If you see a light beam coming through the backlight, then the backlight is burned out and should be replaced. Luckily, the backlight can be easily replaced.
Whether you're addicted to great movies, spend all day playing console games, or want stunning visualizations for the music you listen to, the action never leaves the TV. Everything you see is limited by the bezel holding the 45-inch (or more) screen in place.