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Samsung tv UE50AU8000: screen turns on black and goes off repeatedly

Hi everyone

Somebody threw away this TV and I had to pick it up

As I plugged it to the socket the screen turns on black, and after a few seconds turns off in loops.

After watching a few videos I tried a few things with no success:

  1. Disconnecting the big semi white cable from the main board -the result is the screen turns on constantly on black, and there is a start sound. Then nothing happens, the screen stays on black.
  2. If I cover half of the cable with a tape, connect it and turn the screen on I get the same result.
  3. I tried using the "tape method" on the right side of the screen couple of times while slightly changing its location. Sometimes I got restarts in loops, and sometimes the start sound with black screen. Unfortunately no picture.
  4. During the screen is on, I disconnected the cable connecting the power board (brown) to the main board (green)- the result is the screen's backlight stays on.

What can cause the problem, and how do I solve it?

I'm a biologist, so please be gentle with me 😊

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Update (03/24/24)

I looked on the ribbon cable, and found out its model SFPCX495G-005 (see attached photo).

When I was looking for a replacement online, I found the exact model, yet the latter 5 digits are not the same.

Is it important?

Should I look for the exact numbers on the replacement cable?

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Have you tried a new ribbon cable? Or even found one for sale as in the same boat as you and after a good day of researching online and taking the back panel off and having a play 😅 believe it to be that which is at fault.

Please let me know the outcome as would really like to have a tv again.

crwdns2934271:0crwdnd2934271:0crwdne2934271:0

@stillfixingit I'm still looking for a cable online, unfortunately didn't get it yet. I will update if it works when I have one

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@wildchild38602 let's get organized :-) First we all want to use the same terminology. Obviously you have the back cover already removed. Now take a couple of well focused, large images of your boards and the interconnect cables. Post those with your Question. That way we can see what you see and we will not all just be in the same book but also on the same page. You will need to have a multimeter so we can do some basic checks.

Since you already disconnected the main board and found out that the backlights do come on, that is a pretty good indication (no, not 100% but pretty close to it) that your power board is okay. Let us know what your definition of this "a few seconds turns off in loops" is.

Nothing wrong with being a Biologist. You are still a scientist and you got this. Thank you for picking up the TV and trying to keep it out of the landfill. Gestures like that means a lot to some of us.

Adding images to an existing question

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Hi,

Thank you for your answer, I've added photos of the cables and boards.

I've seen in other issues in the forum that I should use a multi meter, yet I didn't know where and what pins to probe.

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@wildchild38602 remove that flex cable (brown plastic like cable)that connects the long skinny boards (driver boards shown in picture #1) and see what happens.

Everytime you disconnect or connect a cable etc. make sure you turn the power off by removing the power cord. That way we can avoid short-circuiting stuff.

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You mean the one at the bottom of the screen, that has a 'U' shape?

crwdns2934271:0crwdnd2934271:0crwdne2934271:0

@wildchild38602 yes that’s the one :-)

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@oldturkey03 after completely removing this cable and connecting to power, there is a start sound, then the backlight gets on, and a black screen appears, yet no picture

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