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My HD75 - UN75F7100 top half of my screen has begun to darken.. I have uploaded/updated software and did a complete reset… but still the upper half of the screen has this darkened area completely across the top and approximately 1/3 to 1/2 of the screen… serial number is Z7MS3CADA01667D Update (07/18/2017) This is what screen looks like
I had this problem too… and fixed it in about 10 min. I searched the internet for this problem and found many forums with pretty much the same resolution… REPLACE TV. I find it interesting that in almost every single case I read over the last 24 hours… no one… absolutely no one recommended a simple Problem Determination (PD) procedure to quickly determine if the issue was in the TV or outside the TV. Supposedly people spoke to techs on the phone, which in most cases are reading from a tech manual… or try to dial in and update TV firmware remotely… what I didn’t see or read is where someone actually had a repairman look at it.. or did actual PD to eliminate issues with cables or devices connected to the TV. My Curved Samsung UN55JU6700 among several other devices… is connected to an Xfinity HDR and through HDMI cables. So…. the first thing I wanted to do was to see if the problem went away if I changed channels… it did not. Then, would the issue move when using another HDMI source… I turned on my APPLE TV and switched to that as the source. I immediately noticed that the issue appeared to go away… so for grins, I tried my DVD player… and still the problem did not return… Now I know its either the HDMI cable feeding the signal or the xFinity box itself… so I tried a different cable and the problem did NOT go away this time… Now I’m highly suspecting the Xfinity DVR device. I powered off the HDR but the problem still remained … No I’m thinking Im going to have to spend an hour on the phone with a tech that knows less then I do… or spend an hour or two at the Comcast store waiting for a replacement DVR. SO BEFORE I did that, I tried one last PD step … I decided to UNPLUG the DVR and let it do a complete POWER ON RESET … in case something got hosed during the last firmware update…. 10 minutes later… my SAMSUNG is working flawlessly once again. DONE, FIXED (at least in my case). So … if your having this issue… BEFORE panicking from all these doomsayers on the net… that in many cases sell or repair TV … try some simple PD … hopefully you’ll be lucky like I was.
For my TV it turned out to be the cablebox . I ran a picture test with the tech. , and the picture was fine. I rebooted the cable box and it went away!
Be sure to scroll down this string. If you have Xfinity boxes through Comcast, there’s a good chance all you have to do is push the reset button on your cable box. After running through all the reset options for the TV and its various display settings, I read Ray Negron’s post. He suggeste a VERY simple fix that worked great for me. Just hold the reset button on your Xfinity box until the blue power light goes off. Wait 20 seconds and repower the device by pressing the reset button again. Shadow across top of set disappears.
I unplugged everything…. cable box, HDMI cable, TV & even my modem/router…. waited 10 minutes then powered back on & haven’t had the trouble since.
Tony Sinclair that looks more like a bad LED backlight strip. For that you will have to disassemble your TV and the LCD panel. Not a fun thing to do but possible. Of curse you do want to check all the wiring specifically the wiring on the power board. Post some images of your boards and the data label on your LCD panel. Post those with your question. Here is the guide for that Adding images to an existing question It will let us see what you see.
Unplug everything associated with your tv. Wait a minute, then reconnect things. Problem solved with my Samsung 4K.
I had a problem with a single, slim, and kind of blurred looking darker line 1/4 to 1/3 of the way down my screen. I would describe it looking almost like the screen had an indentation or fold more than anything else since the picture underneath seemed fine. I do have xfinity so I tried many of the solutions here. None of them worked and I was starting to get concerned. Being a bit of an extreme troubleshooter I dug into TV settings. I noticed that when I changed various brightness levels the line would move up and down depending on the brightness, with brighter settings pushing it higher but never eliminating. If your Samsung TV has an eco friendly setting to adjust brightness based on ambient light, try disabling that setting. It removed the line I was seeing. Seems like a bug and not a feature in this case. That faint line was driving me crazy! I can’t understand why that was the cause. It was almost as if it was applying a darkening gradient over the entire picture to cause it to emit less light.
SOLVED (for me). I had this problem all of a sudden and i realized it had to do with my TV’s display of my home phone’s Caller ID. To remove the banding, i simply called my home phone number to reactive the gradient and it went away! Yay. here’s the deal…my Cox Contour TV displays a caller ID whenever I receive a call to my home phone number. When this happens the top edge of the screen darkens into a blueish gradient. After the call is answered or ignored the caller ID and gradient (should) automatically go away. At some point i noticed a call come in and I ignored the call, but the gradient did not go away. At first i didn’t realize to consider this, I was trying to find some setting somewhere. Then i remembered seeing that Call ID notification and thought it must have just stuck in the mode. I was right. I just called my home number, saw the Call ID displayed on the TV. Canceled the call. The gradient went away. I hope this helps!
Just had the same problem! Rebooted the box. Grey strip across top of TV gone!!! Thank you! thank you! Thank you!
I had a 2 year old smart TV with the faster chip by Samsung. Same issue. Tried everything including swapping out the cable box, chasing my modem, changing all of the cable connections and it was still there. So, I bought a new 75" for one room, moved the other large screen to our family room and gave the faulty TV to my son who lives in his own apartment. He connected it to his cable box and guess what….no grey line! I don’t think the issue is with the receiver. It is most likely the cable feed into the TV or some kind of radio interference. Try changing the HDMI and coax cables first. Power off your modem, TV and cable box. Change the cables and power everything back on. If that doesn’t work, give the TV away. Good luck.
I have a Vizio D55-F2 with a darkened top half that appears exactly like the picture in the original posting. I disassembled the panel and replaced all defective LEDs, some of which fail open causing an entire strip to go out while others fail shorted allowing other LEDs in the strip to continue working. I tested all the strips before reassembling only to find the problem remained. I then began looking at the signals from the backlight PWM controller and saw that the darkened top strips were actually being PWM’d while the bottom half was full on. By luck, I disconnected the bottom strip’s 58V supply as a test and all other strips came on and, even at 50% duty cycle, it appeared to have a nearly uniform brightness. The darkened state also appears to stem from a possible power up test because the bottom LED row did not light when reconnecting the 58V supply while powered on and it appeared to be no PWM signal for that row as if it had been disabled. The 58V supply is from a very noisy switching circuit and I wonder if the fact that the mosfet for the bottom row is located right beside it could be affecting possibly the current sense going back to the backlight IC. It could also just be the backlight IC is bad, but it is a Novatek NT50511S for which I cannot find a data sheet. For now, I’ll live with it since the missing bottom row is hardly noticeable.
Simply unplug the tv, and unplug the cable box. Wait 30 seconds and plug cable box back in. Wait a few minutes then plug tv back in. Power on tv and after cable box completely resets, the dark portion at the top of the screen is gone.
