Looking for some help please. Samsung UN75RU800DFXZA rebooting, no picture, clicks

[joel warren]

TV was working fine and then just shutdown one day. It will not turn back on. I get a backlight for a little while, then it just clicks and won't fully boot.

I took off the back panel and did the basic troubleshooting and it seems like it's a panel issue.

The backlight will stay on if I disconnect either of the ribbon cables going to the panel. I've watched this video (https://www.youtube.com/watch?v=77tymvTJDxo) and am wondering if this could be the issue, just a bad cap on the panel.

Any assistance is appreciated.

[thetonywarren]

We could try to test caps on the panel, but Im not sure how we can determine what their values should be. Im guessing we would need a different type of meter or tool to test those very small SMD caps.

[EazyBone]

Solder the 2 pts in the picture and then remove the speakers and metal guards protecting the buffer boards on the bottom of the TV. There will be a yellowish U ribbon on the left and right side. Unplug one at a time (don't short it so disc it from the closest to the middle). And plug in the tv. If you get 3/4 a pic you know that buffer boards is where it's disconnected is where the short is. If not, reconnect the cable and do it to opposite side and see if 3/4 picture. This will isolate the short on the screen. But

In the end your screen

[joel warren]

I will try this soon and report back. Thx

[EazyBone]

Also make sure to unplug in-between switches

[thetonywarren]

Solder the 2 pts in the picture and then remove the speakers and metal guards protecting the buffer boards on the bottom of the TV. There will be a yellowish U ribbon on the left and right side. Unplug one at a time (don't short it so disc it from the closest to the middle). And plug in the tv. If you get 3/4 a pic you know that buffer boards is where it's disconnected is where the short is. If not, reconnect the cable and do it to opposite side and see if 3/4 picture. This will isolate the short on the screen. But

In the end your screen

What were you going to say after "in the end your screen"?

[joel warren]

I think he meant , in the end the issue is my screen…. Going to do the suggested testing tomorrow.

[joel warren]

I unplugged the U shaped gold cable on the far left when looking at the back of the tv and got 3/4 of a picture.. so it's the left buffer board that has the short..

any advice on how I can locate the component with the short??

[EazyBone]

Make sure you test right side also (just to make sure I'm sure you did)

Basically you can compare caps from each side of buffer boards, check them using beep beep mode and maybe you will get lucky. If you can't find a short.. well probably internal issue.

Don't forget to unsolder that bridge you made.

And yes in the end, your screen is dead correct.. small chance something else tho! I've never been lucky on it.

[joel warren]

Yes, when I reconnected the left side and unplugged the right side, I didn't get a picture and had the same clicking/rebooting issue. I will test the caps next.

[joel warren]

I'm guessing that it might be the cap at location c211. I used 1 probe on my multimeter on the left side of a cap and get continuity if I touch the left side of any other cap besides c211

[nomoresonys]

The question is do you have continuity to ground on one side of the cap, the other side should not.

[joel warren]

yes I do, I just thought it was odd that I got continuity on the opposite side of c211 from the rest of the caps.

I did not find any shorted caps.

Is there anything else that I can check?

[Diah]

i remember RU series Panel they have at the far end of the panel buffer boards 3 ESD diode... show us .. if there are ESD then one shorted

[EazyBone]

I knew I recalled something like that, I was unsure to say something. Pics of buffer boards!

[joel warren]

[Storyteller12]

Don't see any on that side. Need close up pics of the other side of buffer board.

[joel warren]

[Diah]

is this site when you disconnect the U ribbon you got 3/4 screen ? if yes close up clear photo on these 3 sets

[joel warren]