samsung un50tu8000 and un70yu7000 displays shorted

[sputnikoff]

I have two of these units un50tu8000 and un70tu7000 that have displays shorted.The unit cycle on and off with lamps coming on and going off.When i remove the lvds cable to screen i get the intro sound on both and sets remain on with lamps on.Both have identical boards and little over a year old.Anyone have this issue?

[nomoresonys]

Re: samsung un50tu8000 and un70yu7000 displays shorted

maybe test the little components, ceramic caps etc. on the panel driver board there where your ribbon cable connects to.

[sputnikoff]

Re: samsung un50tu8000 and un70yu7000 displays shorted

So i get a lot around 4-500 ohms or im looking for shorted ones.

[nomoresonys]

Re: samsung un50tu8000 and un70yu7000 displays shorted

yep, looks like the ohms are ok, are any shorted?

[sputnikoff]

Re: samsung un50tu8000 and un70yu7000 displays shorted

No but i will look further.I assume i'm looking for low ohms like 4-5 ohms or close?

[nomoresonys]

Re: samsung un50tu8000 and un70yu7000 displays shorted

yeah, they should probably be over 100 ohms.

[Diah]

Re: samsung un50tu8000 and un70yu7000 displays shorted

ESD diode same to any other NU serie... it will located at the end of the right side bufferboards ( when you look from the back side )... you can check if you have U ribbon on the right bufferboards ... disconected and see if you have 3/4 SCREEN DISPLAY

you can also masking the pins on MB side if you can located them which goes to the end of the mentioned bufferboards.

[nomoresonys]

Re: samsung un50tu8000 and un70yu7000 displays shorted

lots of times it can be cleared up with the tape cut-off method, one of many examples on youtube there: https://www.youtube.com/watch?v=E6gkuTP7Lt0&t=900s

[nomoresonys]

Re: samsung un50tu8000 and un70yu7000 displays shorted

yep, was just about to mention the diode packs, good thread there about them: https://www.badcaps.net/forum/showth...d+diode&page=3

[sputnikoff]

Re: samsung un50tu8000 and un70yu7000 displays shorted

Diah yes i disconnected the U ribbion on both sets and no 3/4 picture,looks like shorted caps on left side.I did find a couple of caps shorted.There is tape method but why not remove the caps?Also my models have one large ribbon cable vs others show two ribbons from main board.

[nomoresonys]

Re: samsung un50tu8000 and un70yu7000 displays shorted

for sure better to replace shorted caps if you find them, the taping isn't for that, you may only have one cap short, can remove one at a time to find out.

[Diah]

Re: samsung un50tu8000 and un70yu7000 displays shorted

can you show us the Panel bufferboards of both side ?

[Fridaycider]

Re: samsung un50tu8000 and un70yu7000 displays shorted

I have the same problem on my Samsung qled tv. Sorry to hijack the thread but can you please tell me how to test diodes ?

[sputnikoff]

Re: samsung un50tu8000 and un70yu7000 displays shorted

Here are pics of bufferboards Diah.I remove a cap that was reading 59 ohms but 59 ohms still remains.

[Diah]

Re: samsung un50tu8000 and un70yu7000 displays shorted

can you tell if these i marked are ESD diode !!!

its strange as you said when remove the U ribbon on each side at time no 3/4 picture...

[nomoresonys]

Re: samsung un50tu8000 and un70yu7000 displays shorted

so does the removed cap read or still read short off the board and are any of the others still reading short on the board? are the pads it came off of reading short?

[sputnikoff]

Re: samsung un50tu8000 and un70yu7000 displays shorted

cap is reading ok pads reading short.I will post pic with microscope tomorrow.Thanks guys for all great help this is awesome forum for sure.

[jason123]

Re: samsung un50tu8000 and un70yu7000 displays shorted

Any update on this? I am having the same problem. Few people are selling LCD Tab BIOS chip. Is this a known failure on these boards? has anyone tried replacing the main board?
Thank you

[nomoresonys]

Re: samsung un50tu8000 and un70yu7000 displays shorted

looks like he gave up on it??

[jason123]

Re: samsung un50tu8000 and un70yu7000 displays shorted

Just got a replacement main board and the system acts exactly the same.