Samsung QLED QN70Q6DTAF Dead 2 blinks Flashing Backlight

[cheebster]

Hello, got a nice 70'' Samsung here that has this symptom, it's (it was) dead with flashing red light, backlight going on and off, looping trying to start up.

So i digged here and youtube, and found the tape method. Got the tv to fire up, however i'm trying to understand what's wrong with it.

At the bottom of the tv, on the panel's PCB there are 3 sections, each of them has 4 connecting tabs to the panel.

So with convering a few pins the tv works, and i messed the flex cable doing so, waiting for a new one to come in to continue troubleshooting.

In the meantime, just poking around, i found these markings as attached in the photo.

STV, CLR CK1 CK2 CK3 CK4 CK5 CK6 CK7 CK8 VSS VGH LC1 LC2
T10 T8 T14 T13 T1 T2 T3 T4 T5 T6 T7 T9 T11 T12

Anyone knows the references to these markings ?

When we are using the tape method, what pins are we covering to have the display fire up ? And also, what is wrong at the end, is it something on the green tab flex on the panel, or really ON the panel itself ?

I'd like to understand what's really wrong with it and how to maybe, find the bad line using a multimeter if possible in any way ?

So many questions

Are the parts on each of these lines after the markings, diodes ?

[itelite]

Re: Samsung QLED QN70Q6DTAF Dead 2 blinks Flashing Backlight

Working on the same tv with the same problem presently in my shop.

Ive isolated the issue to the left most panel board. With that disconnected it will boot up, with it connected it will not.

I have check all components on the panel PCB for shorts to ground and so far all looks normal.

Do you know what pins you covered so far? It could be helpful to know what signal you are covering.

If i figure anything else out of this end i will post.

[cheebster]

Re: Samsung QLED QN70Q6DTAF Dead 2 blinks Flashing Backlight

Hi there, well here it starts at about 7th pin covering 4 or 5 pins on the right panel pcb. Do you mean left most looking at the back, or the front ?

[itelite]

Re: Samsung QLED QN70Q6DTAF Dead 2 blinks Flashing Backlight

left hand most if you are standing at the bottom of the tv by the panel bonded board.

[dskall]

Re: Samsung QLED QN70Q6DTAF Dead 2 blinks Flashing Backlight

Basically, you have a bad panel. It is not repairable in that you cannot repair it back to full glory. You can only disconnect the short. But you will have a degraded picture.

[cheebster]

Re: Samsung QLED QN70Q6DTAF Dead 2 blinks Flashing Backlight

Working on the same tv with the same problem presently in my shop.

Ive isolated the issue to the left most panel board. With that disconnected it will boot up, with it connected it will not.

I have check all components on the panel PCB for shorts to ground and so far all looks normal.

Do you know what pins you covered so far? It could be helpful to know what signal you are covering.

If i figure anything else out of this end i will post.

Hi there, well ive covered 8 pins at the end to get the most decent picture.

What im wondering is: Will this tv fail again, is it because there are so many manufacturing defaults in the panel that it will be unstable and fail in not so much time ?

Im wondering about the long time reliability of the set once 'taped', i got a vizio 65 but i'd rather replace it with that one, i would not feel so confortable selling it.

I bought a second of these samsung qleds, a 58'' this time, with the same symptom.

However, ive just noticed if you leave the tv trying a lot doing it's boot loop thing, it will eventually power on (and then show you lines on the screen where the issue is)

[Ihandyrepair]

Re: Samsung QLED QN70Q6DTAF Dead 2 blinks Flashing Backlight

I am working with this tv too.
have you tired to just cover the clock signal or you had to cover others too?
measure voltage too.
VGH should be 24v

I use the C shape bottom ribbon cable to separate the left or right side panel.
use the test point on the bottom boards to find the Clock signal on the C shape ribbon cables and I tape it there instead of the single ribbon from the main board.

I know the more pin you covered the worst the image.
I was able to cover just CK7 on my tv it works now but there is a single horizontal line across the tv. I am guessing that is the panel issue on mine.