Samsung 4K led model UE50NU7445U no picture

[Davi.p]

Re: Samsung 4K led model UE50NU7445U no picture

" means the panel is already broken so I won't care to find new ESD diodepacks to the bufferboards."
that's nota good idea, the next surge will destroy easier the rest of drivers without diodes..

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Problem is I have no info what diode packs this is and where to get them...

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Pics on buffer boards:
https://www.bildtagg.se/bild/3msuyww1tbu5eqhvqlvvaie
https://www.bildtagg.se/bild/o147wdppblsc0u7xiiaom0e

Diode packs visible on board edges

Anyone able to indentify the diodepacks on the above pictures?

Markings are 4262H and 4267H

[Davi.p]

Re: Samsung 4K led model UE50NU7445U no picture

in a discussion about September or earlier with me i have found it...

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

in a discussion about September or earlier with me i have found it...

With who? Not with me at least
Could you try to find that info ?

[Diah]

Re: Samsung 4K led model UE50NU7445U no picture

Anyone able to indentify the diodepacks on the above pictures?

Markings are 4262H and 4267H

i did find this pack of 10 Pins D at my scarp 1 for hisense and another for Philips. they are 3 in group like the one you showed here. if the DM on Diode mode. (-) on pin 1 will read nothings over all the rest pins from both side. only one D will read 0 (peep tom ) netween pin 1 and 10. this is the same at other TV.

if pin 1 (+) the rest will read some Diode value 965 or doubled , but the one D of the group which i mentioned before will read 0 as above. Notice both TV was just cracked screen with full display before scrap them and took the buffer boards as parts.

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Thanks Diah, the thing is I have already removed the diodepacks since I was suspecting them at fault, before going into the clock lines troubleshooting.
So now I need to find the partnumber of those diodepacks so I can mount them back.
The old ones are gone.

[Davi.p]

Re: Samsung 4K led model UE50NU7445U no picture

ok from my notes file, in Italian:
Per TV Samsung con guasto ai diodi tvs schede pannello provare a cercare rimpiazzo uClamp6514P (UCLAMP6514P.TNT) o forse alternativa uClamp4014P (UCLAMP4014P.TNT) di Semtech
--
these small ants can handle very few current so i think a better replacement would be full size tht tvs diodes, i don't know if there's space for them

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

ok from my notes file, in Italian:
Per TV Samsung con guasto ai diodi tvs schede pannello provare a cercare rimpiazzo uClamp6514P (UCLAMP6514P.TNT) o forse alternativa uClamp4014P (UCLAMP4014P.TNT) di Semtech
--
these small ants can handle very few current so i think a better replacement would be full size tht tvs diodes, i don't know if there's space for them

You can dream, typical italians (I have family in Italy), there is absolutely no place for any THT devices inplace of the small ones...

But do you know what signals the diode packs protect ?
I mean it's only 4 diodes in each package and there are 3 packages per buffer board, so is it TX lines or CLK lines, or VGH VGL lines which is protected?
I could install bigger TVS across the decoupling caps if I knew more about where they are installed.

[Davi.p]

Re: Samsung 4K led model UE50NU7445U no picture

them protects clock signals

[lotas]

Re: Samsung 4K led model UE50NU7445U no picture

Here's about TVS Diode

[alfatv]

Re: Samsung 4K led model UE50NU7445U no picture

Those ESD protectors are mostly useful for external connectors like HDMI, USB.
I would just leave it alone.
Better invest in surge protector for mains and antenna (if used).

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Thanks all for your ESD advice.

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Hello. I mounted new ESD diode packs, but then the same symptom came back.
I used the IP4283CZ10.
When remove again set is working.
From what I can see, the pinout is the same on original and the new ones.
I wonder, what required voltage is required to drive the clock lines, perhaps the new ESD diode clamp to early?

Datasheet to new ESD diodes:
https://cdn.badcaps-static.com/pdfs/...8f794f7f84.pdf

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Today I measured the clocksignals that the ESD diodes protect. The amplitude is about 27V peak so the suggested ESD diodes clamp way too early.
That's the reason for not showing a picture and reboot.
There must be ESD clamp diodes with higher voltage rating.

[lotas]

Re: Samsung 4K led model UE50NU7445U no picture

Marking 4262H and 4267H is most likely 42*** - SP5003-04TTG.