Why Is My Television Screen Looses Brightness Television

Chosen Solution

Toshiba 58L1350UC Hi, I know there are similar posts already open but my case seems different. Because people says the can see an image when using a flashlight on the screen. I can’t see anything even with the flashlight but I still have sound… When I turn my tv on, the screen open but won’t show the thoshiba logo. Then after, 5 seconds the brightness lower at like 50% still no image. 5 second later, the screen goes all black. Thanks for helping me out, the tv is like 4-5 years old but I don’t have the money to get a new one! Francis

@francisg812 since you have sound and you are saying the you have a backlight but it decrease that would lead me to check the main board. Since this is a Toshiba (totally paranoid company and prosecutes DIY’ers) it will be hard to get schematics. We will need you to post some good images of all of your boards with your question. That way we can see what you see. Use this guide Adding images to an existing question for that

This sounds like a faulty LCD or a faulty back light LED/s. I would suggest to look and see how much replacement back light LED strips are for your model and give the replacement a go (given that they are not expensive). If that doesn’t work then you’ve just replaced your LED strips anyway so you’ll have fresh back lights. I would suggest an LCD replacement after that if the problem persists, not sure whereabouts you can get replacements but google is your friend :). Good luck.

With no logo, but brightness, the problem is not the LED strips. These are working and would not dim under normal circumstances. It sound to me like the screen is being told to be dark. Normally, the logo is generated internally and sent to the screen as the first operation. With a completely dark screen, this logo is not making it to the screen. This is controlled by the main board in your set. It is possible that there are a couple of problems here as well. Please update this with a few photos of the boards and verify the model number. The pictures may yield a few clues. Thanks, Dan