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Jack, Technician
Category: TV
Satisfied Customers: 9915
Experience:  40 years experience as audio,video repair and installation tech
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My 50 Samsung Plasma TV has sound but the screen is black,

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My 50 Samsung Plasma TV has sound but the screen is black, there is audio and the blue ring around the on and off button is not blinking. Is this the power cord gone bad?

Jack :

Hi and thank you for using justanswer.

Jack :

From your description it sounds like you may have a defective Xsustain board.


What is a Xsustain board? And would we have smelled something that smelled like burnt food before it went out?

Jack :

The smell is a definite possibility

Jack :

The Xmain is one of the board connected directly to your plasma panel that drives the picture


Are theses boards expensive to replace or should we just get a new TV?

Jack :

If that board is defective , you can buy it for around $90

Jack :

So if you were to do the work yourself that would be about it + shipping


Is it something that we might be able to replace ourselves or do we need a repair person to do it?

Jack :

This is not hard work to do if you are handy with a screwdriver

Jack :

It would require taking off the back cover first and make some test to confirm the problem


How we would do the test?

Jack :

Do you happen to have a meter ?

Jack :



Yes, my husband uses it a lot.



Jack :

That would be perfect, i could upload a picture of that board and show you were is the fuse located, that would be the first thing


That would be great. We are getting the meter now.

Jack :

what i can do is switch this chat to standard Q&A mode and you will get an email with a link to get back to me once you are ready.

Jack :

You will need to take the back cover off and there is quite a few screws


Okay, I will open up my email and look for the link.

Jack :

o.k and i will also upload that picture


Thanks for all this great help.

Jack :

Look for 2 emails after i close this chat



Jack :

Talk to you soon


Looking forward to it.

Jack :


Jack :

can i close it now ?

We are now in Q&A mode.

Here is that picture and you will see the fuse i pointed.


If that fuse is blown, DO NOT REPLACE IT as it means that board is gone and replacing the fuse might just cause further damage to the rest of the tv.

Customer: replied 6 years ago.

We have just tested the fuse and the fuse is good. Is there another test that we should do?


Customer: replied 6 years ago.


We ran a continuity test on the fuse and it was okay. Is there another test we should do?

On the other side of the tv there is the Ysustain that should have a fuse or two as well.

Also, since you did smell some burning, try to see if there is anything that looks burned or discolored by heat.


As it is getting pretty late in eastern time(near midnight) can i get back to you tomorrow on this ?

I will have a few more pictures and voltages test for you by then.

Customer: replied 6 years ago.
We don't see any more fuses, so I think waiting until tomorrow is a good idea. How should we get back in touch?
The same way we are communicating tonight, i will message you or you can and i will get back to you as soon as i can.
Customer: replied 6 years ago.
What time do you start working?
Whenever i am ready since i do this from home but i could be online at around 11 AM EST
Customer: replied 6 years ago.
That is good as we live on the West Coast PST. We did find the fuses, but we will talk to you tomorrow around 11 your time. Good night.
O.k then talk to you tomorrow at around that time even though it might be a bit early for you ??
Customer: replied 6 years ago.
We are back on line as soon as you are ready.

Good morning


Found anything new like burnt component or blown fuses ?

Customer: replied 6 years ago.
No nothing burnt and we found and tested six more fuses. They were all good.

o.k then, it is not always apparent but the bad smell is a definite give away that something is burned.

i`m just getting started here today so could you give me an hour or so to gather some info,pictures, voltages etc ?

Customer: replied 6 years ago.
That's fine. Look forward to hearing from you later.

Hello, i have here a picture of your Ysustain AKA Ymain.

Fuse is indicated with the arrow.

We`ll do some voltage tests today and unless specified otherwise, all measurement will be done with the DC scale of your meter and the metal chassis will be used as ground for the black probe of your meter.

If you look at the back of your plasma panel there will be a sticker with voltages indicated by letters like VA,VS,VSC,VE etc.

Those are the voltage specific to your plasma panel.

The first voltage we`ll measure is the VS, it will be written on that sticker and should be around 200 volts.

This voltage can be found on either fuses i pointed to , when the situation is normal.

So if you start with that , then we`ll take it from there.

Here is that circuit;


Customer: replied 6 years ago.

With the TV turned on the fuse that we tested yesterday was 3.4 and the one from the drawing up above is 80.0. The sticker is showing the VS should be 200.

O.k not good in either case.

So what i`d like you to do next is to pull out (one at a time) the connectors i indicated on your boards and measure the voltage again but on the board that is still connected.

In other words pull one off and measure the other board then vice versa.






Customer: replied 6 years ago.
With the connector from the bottom picture unplugged the top picture fuse reads 60. With the connector from the top picture unplugged the bottom picture fuse reads 3.8.

o.k then can you see where those 2 cables connect in the power supply circuit ?

Both of them should meet in the power supply.

And should indicate The VS voltage on some of the connectors pin/wires


Once you found it i`d like you to disconnect first the Xsustain(bottom board) and measure the VS in the power supply, then same thing with the other board(Ysustain)


The idea is to see if the voltage will rise in the power supply with either board disconnected.


Or there could be a simple test with the Xsustain(bottom board) , unplug the tv and the connector and measure for continuity between ground and that fuse.

By the way; the 60 volts you are reading must be the VA voltage indicated on that sticker.

If so then it is normal.

All that`s left to do is find out what is happening with the VS

Customer: replied 6 years ago.
With the Xsustain board unplugged the voltage was still 3.0. With the Ysustain board unplugged the volage is 3.7. We will do the simple test now. Our sticker for the VA voltage is 70.
O.k but i have a good feeling that there won`t be any short to ground and that the power supply circuit is defective.

This is your power supply circuit and you can see that i circled some capacitors.

Can you tell me if some of them seem to have a rounded top compared to others or even fluid leaking through the top.

Normal capacitors should havea perfectly flat top


Customer: replied 6 years ago.
Did you received my last replay that said all of the capicators are flat and there doesn't seem to be any leakage?

o.k no problem.

How about the continuity/short test to ground ?

That is the fuse on the Xsustain to ground.


In any case at this time ,from the test you made i`m almost positive about the power supply circuit being defective.

Just need to confirm again that there is no VS voltage in the power supply while both the X and Y sustain are unplugged.

The short test will be to find out if the Xsustain might not be gone as well.

Customer: replied 6 years ago.

With electrical service unplugged there is no continuity between ground and the fuse on the Xsustain board.


We redid the tests with the X and Y sustain plugs unplugged. With both unplugged we got a 5.0 with both tests. With the X unplugged we got a 3.7 on the Y and with the Y unplugged we go a 3.0 on the X

O.k then that confirms it.

The power supply circuit alone is defective.


From what you told me about the capacitors for example, there is no point at this time to try to repair that board.

The separate part that produce the VS voltage is defective .


Which means the best way to go about it is to replace that board.

I have here an address(below) where you can buy it;


That store is probably the best i could recommend.

Also since they had some website problems recently they are offering a 15% discount, you will see it on that web page, if you`re going to order from them make sure to take advantage of it.

If you decide to do your own shopping then you can use this part number : BN96-01801A


Finally, after the test that you/we made, i am confident that replacing that board will restore your tv to its normal operation.


Hope this help and let me know if you have any questions.
Thanks again.

Customer: replied 6 years ago.
Thanks for all of your help. I will get that board ordered today. It has been a pleasure working with you.

Same here and if you have any questions at any time you can reach me here.

Thanks again.

Jack and other TV Specialists are ready to help you