Samsung 4K led model UE50NU7445U no picture

[Diah]

Re: Samsung 4K led model UE50NU7445U no picture

yours Panel Taiwanese AUO. the driver board and the response to firmware (main boards action)are the one on the left side (if you look on the tv from the back with out cover) check if you have the 8 pin chips. write down its label and upload focused photo to the area around it over here in this forum .. please don't use external server for upload.

[Davi.p]

Re: Samsung 4K led model UE50NU7445U no picture

I would assume there would be a unbalance if one of the led strips were bad, right ?

it seems so.. this if the lamps are lit...

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Here is a photo of the chip.
It's placed on the left side of the panel (looking at it from backside)

Tried to insert in post, but no joy...

https://www.bildtagg.se/bild/dxykrfx8xd8ikr8ztxhqgf7r

[Diah]

Re: Samsung 4K led model UE50NU7445U no picture

Here is a photo of the chip.
It's placed on the left side of the panel (looking at it from backside)

Tried to insert in post, but no joy...

25Q32JVSIQ take it out.. dump it and flash new chip with yours dump and put it on the board.

at future use GO Advanced so you will be able to upload photos as jPG format

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Thanks Diah, could you direct me to a flash programmer that is compatible with this chip?

[Diah]

Re: Samsung 4K led model UE50NU7445U no picture

Thanks Diah, could you direct me to a flash programmer that is compatible with this chip?

the cheap one CH341A with clip can do the job..
you can test the chip on the tv as it had beside as SPI contain I/O function.. firsts read the voltage on VCC PIN ( PIN 8 ).. then try freez it or heat it then turn on... hope yours screen will come on

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

the cheap one CH341A with clip can do the job..
you can test the chip on the tv as it had beside as SPI contain I/O function.. firsts read the voltage on VCC PIN ( PIN 8 ).. then try freez it or heat it then turn on... hope yours screen will come on

VCC is ok (3V4) also SPI, CLK, CS, MISO, MOSI has "activity" and no abnormal waveforms.
Thermal cycling of the chip does not change behaviour...

NOTE! When boot fails -> Standby led blinks TWO times. Then it all repeat...

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Followed this vid:

https://www.youtube.com/watch?v=E6gkuTP7Lt0&t=900s

Screen is OK!!!

Now I need to find new ESD diode packs to remount.

[kevinallein]

Re: Samsung 4K led model UE50NU7445U no picture

Can you please explain, which pins exactly you blocked with tape ?

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Can you please explain, which pins exactly you blocked with tape ?

https://www.bildtagg.se/bild/0m64i6ybovlhznm0xg54mh01

This is the ribbon to the right buffer board if looking at the tv from backside.



I have no clue what signals this is, or what effect it will have.

[kevinallein]

Re: Samsung 4K led model UE50NU7445U no picture

I am trying to count, but it looks like you are blocking 13 lines starting from PIN 16 ? Is that correct ?
That totally confuses me. I thought you would only block the CKVx and CKVBx lines, which should be 8 in total ?
Where did you get the info, what to block ? Could you please explain ?

I found a Samsung KS Service Manual, slightly different from the one I have, but here is the pinning info I found in there.

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

I am just a surprised as you how this could actually work.
The tape is blocking 12 lines from start pin 16.

I was looking at the youtube vid and decided to give it a go.
Did not look very carefully how much pins to block and from where actually.
The first try I made resulted in a properly working tv, with no picture side effects.

I will try, by your pinout information, to see what signals I actually blocked.
Could you upload the complete service manual ?

And what does the CKV lines do ?

[Davi.p]

Re: Samsung 4K led model UE50NU7445U no picture

you probably blocked clk signals due to the fact that your gate driver circuits connected to the clocks are s/c..

[lotas]

Re: Samsung 4K led model UE50NU7445U no picture

And what does the CKV lines do ?

The CKV signals control the on / off frequency of each line. (CKV line switching signal in line drivers)

[kevinallein]

Re: Samsung 4K led model UE50NU7445U no picture

I am just a surprised as you how this could actually work.
The tape is blocking 12 lines from start pin 16.

I was looking at the youtube vid and decided to give it a go.
Did not look very carefully how much pins to block and from where actually.
The first try I made resulted in a properly working tv, with no picture side effects.

I will try, by your pinout information, to see what signals I actually blocked.
Could you upload the complete service manual ?

And what does the CKV lines do ?

I did actually find a NU Service Manual, that is probably more appropriate for you. Am I allowed to upload here ?

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

you probably blocked clk signals due to the fact that your gate driver circuits connected to the clocks are s/c..

Could you expand your reasoning please.
From looking at the pinout for connector CN1802 (right side) and assume this also applies to my set I can tell those below signals are blocked:

I will now try to narrow the blocking down to the smallest amount of signals needed for picture

[diif]

Re: Samsung 4K led model UE50NU7445U no picture

Click go Advanced, click on the paperclip and add the image not the url.

[Diah]

Re: Samsung 4K led model UE50NU7445U no picture

the supject become more interset.. i think if you block only ASG_MON_R_MB4 with its respose STV_MP4 would enough... but let see these pins where are going.. as there no diagram i think they are return signal to MB.

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Click go Advanced, click on the paperclip and add the image not the url.

Thanks... I was trying to "insert image"...now it makes sense

[PowerAmpFreak]

Re: Samsung 4K led model UE50NU7445U no picture

Going for Diah's advice blocking only 3 pins made the bootloop come back.
Explanation:
Blocking all blue markings - set is OK
Blocking only the red markings - Set goes into bootloop
Now extend blocking to cover a few of the CKV lines aswell. Stay tuned.