Solved Backlight Turn Off After Few Seconds Television

Chosen Solution

Hi, I found a tv (Kunft 395vdlm14, tv led) in a trash can a couple of months ago. The tv does turn on but the backlight goes off after few seconds (10-15 seconds). I can still hear the audio and still see the video if I point the screen with a torchlight. I ordered a power board before finding out that it wasn’t the problem. So I disassembled the tv and turned on the leds, and I found out that the middle strip has one led turned off. Could it be the culprit of the entire set of 5 strips going off after few seconds? Also, if i turn on the tv while still hot it turns off faster (2/4 seconds) This is a picture of the leds turned on.

Thank you for your help.

@jachavik yes it is absolutely possible that this is caused by a failed backlight LED. Replace the strips so that this won’t happen again and then re-evaluate. You could of course also try to replace the single LED or even use a 3V 90mA Zener diode instead of it and see what happens.

The LEDs might be drawing too much current if that LED is shorted. The control circuit might be defective if it is varying the intensity of the LEDs. How did you activate all the LEDs?