Samsung UN82MU800DFXZA - Black screen+Sound works

[Island_Stylin]

Hey Everyone!

I am a newb when it comes to fixing televisions. Please forgive me if I don't include all the details necessary.

I have a Samsung UN82MU800DFXZA television. I have taken off the back of the tv and can see that the lights are in fact on producing a white light, but front of the tv shows a solid black/bluish color. Did a flashlight test and see nothing. The sound is crystal clear when I put on a station.

After watching a few videos I figured I would order and replace the TCON board. This didn't fix the issue. At the same time, the board I bought maybe bad. I am very new to testing and diagnosing a tv and not entire sure on how to use a multimeter (when to switch it to which icon), but I'm attempting to learn as this TV was costly. Plus the more you know! Right?

Any diagnosing help would be greatly appreciated. I want to rule out the 3 components, but I am not sure how to tell if the T-Conn unit I bought is even functioning properly.

Thank you

[budm]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

1) Please attach good clear pictures of the whole back side of the TV showing all the boards using 'GO ADVANCED'.
2) Did you verify that you do have 12V DC at both ends of the T-CON fuse with ref. to chassis ground?

[Island_Stylin]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

1) Please attach good clear pictures of the whole back side of the TV showing all the boards using 'GO ADVANCED'.

Attaching photos of board. Let me know if these are clear enough. Including the old tconn board (2nd to last photo) as well.

2) Did you verify that you do have 12V DC at both ends of the T-CON fuse with ref. to chassis ground?

I am not sure. I am assuming I need to use the multimeter to check this?

[budm]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

What is your experience in troubleshooting electronics and tools usage knowledge?

[nomoresonys]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

Look at the long white stickers on both tcons, what are the top numbers on both?

[Island_Stylin]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

What is your experience in troubleshooting electronics and tools usage knowledge?

Very little unfortunately. I understand very basic knowledge when it comes to electronics. I understand using the black for ground and the red to check the board on a multimeter.
I have built my own computer from the ground up. Tinkered with small jobs (installing ceiling fans, re-soldering remote controls when its discernible there is an issue.

Look at the long white stickers on both tcons, what are the top numbers on both?

Old Unit : BN96-44749H RoHS 82F
New Unit :BN96-44749H RoHS 82F
Old Unit sku : MX37BN9644749HUL1DJ810167
New Unit sku :MX37BN9644749HUL1DJBSO466

[nomoresonys]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

Ok, that's surely a match, should test the fuse on tcon as suggested, I looked but couldn't find the fuse, do you see anything with label starting with F on the tcon?

[Island_Stylin]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

Ok, that's surely a match, should test the fuse on tcon as suggested, I looked but couldn't find the fuse, do you see anything with label starting with F on the tcon?

How would I test the fuse? What are the settings I should put on the multimeter?

[nomoresonys]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

Set it to 20 vdc, black negative probe on tv metal chassis, red positive prob on each side of fuse.

[budwich]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

try unplugging the cabling from the tcon to the panel... one cable at a time (of course, doing the cable manipulations with the power off) and see if it changes the response / display. go from the results.

[Island_Stylin]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

Apologies for the delay.

Set it to 20 vdc, black negative probe on tv metal chassis, red positive prob on each side of fuse.

I tested the fuse in the image below. I couldn't find another area with an F on it. Should there be more than 1 fuse on this board?

Measured at 12.77V


I also acquired another main board to swap out with the board I have. Same issue persists. Front of screen is a blueish solid color throughout.

[Island_Stylin]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

try unplugging the cabling from the tcon to the panel... one cable at a time (of course, doing the cable manipulations with the power off) and see if it changes the response / display. go from the results.

I tried to unplug one side of the TCONN (2 cables) and turned the tv back on. Nothing changed. Same with the other side. No change. Same solid bluish color throughout the front.

[nomoresonys]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

Could try the "cut tape" method, just for fun, see what happens, sometimes you have to play with the size of the tape to get it just right: https://www.youtube.com/watch?v=7TT8QYeN1s8

[nomoresonys]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

Maybe take a good look at the cable from powerboard to mainboard, see if anything looks burnt or brown around the terminals and such.

[Nick's Tvs]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

We recently fixed 2 of these and had very similar failures as you did.
Both were T-con board failures. 1 we were able to heat up the BGA chip with hot air to confirm the failure and were able to get it to temporarily work.
Replacing the T-con fixed it.
The second one heating it didn't do anything but freezing it with freeze spray did the trick. We also replaced the T-con and it also fixed it.

Both customers did however tell us that the issue was not sudden, it was progressive meaning that the TV would work fine for a few hours and then the picture cut out but audio was good.
Backlight and audio would always stay on but picture would go away.
Then the issue would get progressively worst to the point where the TV would only show picture for 1 minute before it went completely out.

[nomoresonys]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

Well then, maybe they sold you a bad tcon or it got borked in shipping.

[budwich]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

I tried to unplug one side of the TCONN (2 cables) and turned the tv back on. Nothing changed. Same with the other side. No change. Same solid bluish color throughout the front.

that would appear to indicate that some of the voltages moving from the tcon to the panel are not there. It is likely the tcon has issues. It might be confirmed with some measuring of voltages at the board (look for the labels / points). It sounds like you should be heading towards a replacement card.

[Island_Stylin]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

We recently fixed 2 of these and had very similar failures as you did.
Both were T-con board failures. 1 we were able to heat up the BGA chip with hot air to confirm the failure and were able to get it to temporarily work.
Replacing the T-con fixed it.
The second one heating it didn't do anything but freezing it with freeze spray did the trick. We also replaced the T-con and it also fixed it.

Both customers did however tell us that the issue was not sudden, it was progressive meaning that the TV would work fine for a few hours and then the picture cut out but audio was good.
Backlight and audio would always stay on but picture would go away.
Then the issue would get progressively worst to the point where the TV would only show picture for 1 minute before it went completely out.

The issue we are having was very sudden. Out of nowhere the TV stopped working. Went to black. Now when we turn it on it just has a solid bluish tint to it. There is no signal of anything else (tried the flashlight test)
We have tried the old and the new T-con board and neither have changed the results we are seeing. Can you pinpoint where I would have to heat or freeze to figure out if the boards are both bad?
Other ways to discern if the board is bad? What are the multimeter settings to test the power going into the board? Set it to what exactly?

[Island_Stylin]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

that would appear to indicate that some of the voltages moving from the tcon to the panel are not there. It is likely the tcon has issues. It might be confirmed with some measuring of voltages at the board (look for the labels / points). It sounds like you should be heading towards a replacement card.

Could you help me explain how I would test the voltage going to the board and leaving the board? What settings I should set my multimeter to? I understand you don't test at the power, but at the points next the power as they match up to the total connections. Where the arrow is pointing is where I would test, right?

[Island_Stylin]

Re: Samsung UN82MU800DFXZA - Black screen+Sound works

Could the Screen be the issue here? Perhaps the new parts we were sent actually work?

I am unsure how to completely rule them out