Samsung 50" Plasma PS50A556S2FXXU

[AJ11R83]

Hi Guys

I have a problem with my Samsung PS50A556S2FXXU

I have two horizontal 1.5" black lines runing through the top half of the screen.

They are not ghost black lines but solid lines.

Im quite competent in electronics repair, id just like to know if im wasting my time with a faulty display panel before I start fault finding the electronics.

Hopefully some one can help start me off.

Cheers
Alan

[AJ11R83]

Re: Samsung 50" Plasma PS50A556S2FXXU

Cant seem to edit message, on closer inspection the two lines are half solid half ghosted. Il try to include a picture in a min.

[AJ11R83]

Re: Samsung 50" Plasma PS50A556S2FXXU



Both lines are solid to a point (see tape marking end of solid line, left to right), the picture isnt too clear, you can see the top line, basically the bottom is the same.

Any help much appreciated.

[AJ11R83]

Re: Samsung 50" Plasma PS50A556S2FXXU

Ok so I noticed this too... Ghostly white shape..

[PlainBill]

Re: Samsung 50" Plasma PS50A556S2FXXU

If the black line does not run the full length of the panel, it's a defective panel, If it runs the full length of the panel it could be either a defective panel or a bad (open) Y buffer.

PlainBill

[cadiman]

Re: Samsung 50" Plasma PS50A556S2FXXU

That bar is a whole buffer dropped out. The upper buffers see alot of heat and so does the y board. I would ohm the buffers then go after the y board. I haven`t seen this on samsung. The one( my first) I just worked on were all caps on all the boards. They had picture issues after warm up or about one Harry Potter movie. Some of the samsungs had heat sinks on the buffer chips and some didn`t. This should be a two part buffer board. The top shouldn`t cost that much. There should be a way to check each input to the buffers to see if you are getting signal to dead buffer.

Wizard or Plainbill will know.
v is very high so be careful.

[AJ11R83]

Re: Samsung 50" Plasma PS50A556S2FXXU

If the black line does not run the full length of the panel, it's a defective panel, If it runs the full length of the panel it could be either a defective panel or a bad (open) Y buffer.

PlainBill

The black line is pure black to a certain point, then its faded-ghosted like the rest of the way across the screen

[AJ11R83]

Re: Samsung 50" Plasma PS50A556S2FXXU

That bar is a whole buffer dropped out. The upper buffers see alot of heat and so does the y board. I would ohm the buffers then go after the y board. I haven`t seen this on samsung. The one( my first) I just worked on were all caps on all the boards. They had picture issues after warm up or about one Harry Potter movie. Some of the samsungs had heat sinks on the buffer chips and some didn`t. This should be a two part buffer board. The top shouldn`t cost that much. There should be a way to check each input to the buffers to see if you are getting signal to dead buffer.

Wizard or Plainbill will know.
v is very high so be careful.

What do you mean "ohm the buffers" and go after the y board?

I can get a y board for £36 to try it i guess http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWNX:IT

Thanks for the help so far guys

[AJ11R83]

Re: Samsung 50" Plasma PS50A556S2FXXU

Think i may understand the "ohm the buffers"
found this when googling - http://blog.coppelltvrepair.com/2010...er-boards.html

[Wizard]

Re: Samsung 50" Plasma PS50A556S2FXXU

Upper Y-buffer board, replace. If the bars are above the "mid-line", that's upper. If below that, lower buffer.

Some panel use one long Y-buffer board.

Cheers, Wizard

[AJ11R83]

Re: Samsung 50" Plasma PS50A556S2FXXU

Thanks Wizard
I take it thats the top left pcb in this picture?

[AJ11R83]

Re: Samsung 50" Plasma PS50A556S2FXXU

Well my new pcb arrived quick, and thats made no difference :-(

On the Xmain I found this on one of the ribbon cables (in line with my two faulty horizontal lines, looks like a small burn? :


Thats on this PCB the other side of the tv, when I pull the top one I lose a small part of the top of the screen, the second one down fills the 2 black lines together. So that sounded normal, untill I pulled the 3rd and nothing, 4th nothing, 5th nothing but 6th I lost the whole bottom half of the screen...

Any idea

[Dgtech]

Re: Samsung 50" Plasma PS50A556S2FXXU

In that last picture, my eye catches the poor soldering on the capacitor above the ribbon cable. May not be important but... what quality.

[Wizard]

Re: Samsung 50" Plasma PS50A556S2FXXU

Now see why I do not like working on plasma TVs on contract and out of warranty since sometimes I must do board swapping to fix the problem. I do not have used parts on hand. I want component level troubleshooting back NOW.

Back to yours, either logic board (behind the mainboard, mounted on the panel itself, roughly in center and bit lower). Or mainboard.

Cheers, Wizard

[AJ11R83]

Re: Samsung 50" Plasma PS50A556S2FXXU

I see, I got loads of service manuals but not one for this tv, It gives me an idea though.
All they do is replace y-x-z. So a service engineer has these full set of pcbs(in an ideal world!) and just swaps them out.... job done in 15mins then.

I prefer the component level fault finding too, il try with these pcbs doing ohm test comparisons.

Wizard what do you think of what looks like a burn on a ribbon cable going into the Xmain pcb?

Also I have 6 going into this xmain - what do they actually do?

Whats the best way of testing the logic board?

[AJ11R83]

Re: Samsung 50" Plasma PS50A556S2FXXU

So New logic board arrived this morning, fitted.... No change :-(

Think im going to just stick it on ebay.
Thanks for all the help though guys

[smason]

Re: Samsung 50" Plasma PS50A556S2FXXU

No-one commented on the ribbon cable. Looks like very possibly a problem there.
What does the other side of that cable look like?

[PowerAmpFreak]

Re: Samsung 50" Plasma PS50A556S2FXXU

But these flatcables has only one pole, right? In the contact there are several pins, don't know why, just to split currents possibly.
I recently changed a Z-SUS on a Hyundai HY4210 (see another thred) and I noticed that both flatcables were solid through, one pole.
So a small damage somewhere would not affect, right?
Any of the experts here has to verify this.

[Dgtech]

Re: Samsung 50" Plasma PS50A556S2FXXU

it would be nice to see what the other side of this cable looks like. That would tell you how many conductors are in it.

[PowerAmpFreak]

Re: Samsung 50" Plasma PS50A556S2FXXU

it would be nice to see what the other side of this cable looks like. That would tell you how many conductors are in it.

In mine, backside was only one pole aswell.