Samsung UN70NU6900FXZA - Red Light Blinks 2 Times Then Screen Flickers

[Samunggg]

I've happened upon this TV, it came with no power cord or remote and it seems to be experiencing a common issue where the red indicator light blinks 2 times then the screen flickers as if it's trying to turn on. No picture, no sound. I suspect the functions of the TV are in good order and that the underlying issue is with the power button which is missing. It's just a white tab where the button should be which means I can't cycle it.

I wanted to know if there is anything I can do or if I should just get a replacement module with the hopes it will fix the system. Alternatively if I can tape the pins to get it to function that would also be acceptable. It just seems like removing the back cover will be a bit of pain so I don't want to start without getting feedback so I hopefully don't do it twice.

[EazyBone]

Re: Samsung UN70NU6900FXZA - Red Light Blinks 2 Times Then Screen Flickers

This is a common thing for Samsungs and the 2 blink means a panel short. TV is probably garbage. Take the back off and disconnect one lvds cable from main to tcon ( if there is one) assuming there is more then one lvds cable. Then plug power in and try again. If error code stops, there is a short on that side of panel. Sometimes you can fix it with tape. Google Samsung TV fix with tape. This has never fixed my Samsung though. I mean it worked but the picture was half purple or something. Good luck

[Samunggg]

Re: Samsung UN70NU6900FXZA - Red Light Blinks 2 Times Then Screen Flickers

I finally took it apart and disconnecting either of the ribbon cables does nothing to the image. There is a start-up sound, the backlight comes on but neither half displays an image. Granted I don't know the start up behavior when not connected to a input source for this TV and the power button is broken so I only have it's on-power behavior to go off.

I did pull the power board and I'm not getting OL across the fuse, although I was having a hard time getting a consistent reading for resistance at 20k, I tried checking some transistors following another video and cannot get a reading at the pins but it could also be some residual epoxy messing up my measurements.

Edit: When both ribbons are plugged in it does the 2 blinks and cycles the backlight, but I disconnect either ribbon cable it doesn't do 2 blinks, the backlight stays on, and there is a start sound.

[lotas]

Re: Samsung UN70NU6900FXZA - Red Light Blinks 2 Times Then Screen Flickers

To check the behavior when removing each cable, you need to place a jumper on the motherboard between the FB_TRDY_1 and FB_TRDY_3 test points.

[Samunggg]

Re: Samsung UN70NU6900FXZA - Red Light Blinks 2 Times Then Screen Flickers

So using youtube videos I tracked the problem to the panel, there are three smaller boards that connect the ribbon cables to the panel. I started by pulling the ribbons bridging the smaller boards, but no dice. Then I started taping pins moving across one of the ribbons until I got an image.

After taking a break I'll start searching for the bad pins that gets me the best image with least pins covered.

[Samunggg]

Re: Samsung UN70NU6900FXZA - Red Light Blinks 2 Times Then Screen Flickers

I don't know if there is a way to a flag or flair a thread as "fixed" although there is possibly room for improvement. I managed to get functionality by taping one pin. However the screen has a dark bar on the far right, some horizontal lines, and a bit of flickering. Haven't figured out if I can tolerate it. I'll also update with a more detailed solution and process by which I determined the underlying fault.

My understanding is when you get to the ribbons that go from the TV panel to the rest of the boards there is nothing more that can be done to improve image quality.

[EazyBone]

Re: Samsung UN70NU6900FXZA - Red Light Blinks 2 Times Then Screen Flickers

Sometimes it's better quality if you do more pins. It may be a short on one but that flickering may go away if you cover say 6. There will still probably be a defect but it may improve to a more tolerable state. But yes I haven't ever used the tape method with a Samsung and made it to my liking. I usually donate the TV after I find the most tolerable state and let the person know it could go tomorrow or last another year.