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Electronics => Repair => Topic started by: Droogkloot on April 18, 2020, 11:48:46 pm

Title: Samsung ue55ks8000 uhd tv won't start up
Post by: Droogkloot on April 18, 2020, 11:48:46 pm

Hi, i'm new on this forum but i'm here to get some help with a samsung tv.
What it does is when powered on the backlight flashes on and then goes out. With the t-con board and all other connectors disconnected from the mainboard the problem is still there.
When i disconnect the mainboard the backlight stays on.


I have checked the caps on the output side of the power board, these tested ok.

I have swapped out the power supply board, this didn't solve it.

Does anyone here have experience with this kind of stuff?

I have made a short recording of this problem..

https://www.youtube.com/watch?v=T5gpyB7ZBkc (https://www.youtube.com/watch?v=T5gpyB7ZBkc)

Title: Re: Samsung ue55ks8000 uhd tv won't start up
Post by: JKKDev on April 20, 2020, 06:01:13 am

Can you determine if the issue is with the backlight or something else? Is picture present when the backlight is off (to check use a flashlight at an angle almost parallel to the screen and you should see some resemblance of an image/letters/whatever should be displayed)?

You could find the backlight enable pin and see if it corresponds to the backlight turning on and off.

Just a few questions to start on :)

Title: Re: Samsung ue55ks8000 uhd tv won't start up
Post by: Droogkloot on May 11, 2020, 11:16:45 am

Hi.  I have looked at it.  No picture or letters on the screen. Only the backlight going on and off. Could it be a voltage regulator issue on the mainboard? If so what is the best way to test it?