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My Samsung un55tu7000 TV has an issue where sometimes when the TV turns on the image doesn't appear or is very faded (see image attached). Otherwise other times the image comes on and I can watch without any problems. Any idea what could be the issue?
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Hi, I had the exact same problem. The version I have is un55tu7000fxza. When switching on from cold, a picture would either be dark, dim, or full brightness. Never knew what I was going to get. The lcd panel was fine, ie, I could see a picture if shining a flashlight into it. What I discovered is that by applying some gentle flexing to the tv, mainly towards the bottom, I could alter the brightness. Sometimes it took a fair bit of time to get the picture stable in terms of brightness. An obvious bad connection somewhere. Took the back off and gently flexed the main board with an insulated tool in various places. Wiggled the connections, especially the one that powers the backlight. All was good. Some gentle tapping on the metal backplate showed that the backlight was sensitive to this tapping. Time to take the lcd panel off. With the backlight led strips exposed, I wiggled each one of them, especially in the middle connection where two strips butts into each other. The strip closest to the bottom felt very loose. Took that set out and tried to make the pin/socket sit more snug. Couldn’t get that to work. So, I decided like any respectable hacker would do, I soldered a small wire bridge across each set of pins. Reassembled everything. All good! Yes, you would have got the same results with a new set of led strips.
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@kissprinciple I would assume electric tape around the pin/socket connection would have the same effect as soldering, right? My soldering skills are poor at best lol
Actually, no. It’s like plugging in a lamp into a wall power socket. Let’s say that instead of the plug being a snug fit, it moves around easily. The lamp will start to flicker, go off, stay on etc as the plug moves around. Ie, the electrical connection will be intermittent as you move the plug around. In my case, that’s similar to what was happening on the led strip. The electrical connection needs to be fixed somehow. Tape won’t do that. So, there are three basic choices; 1) replace the led backlight strip, 2) fix the mechanical issue on the socket/pin so that a better, more reliable connection is made, or 3) solder a couple of jumper wires so that a permanent electrical connection is made. I couldn’t get #2 to work reliably. I didn’t want to order and wait for parts, so #1 was out for the moment. That left #3 :-)
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Hi @godfather17
Try the following to check if the screen LED backlights are working OK.
Disconnect the power to the TV and then remove the back cover from the TV.
Disconnect the mainboard-power board cable at the power board end only.
Reconnect the power to the TV.
The screen LED backlights should turn on full and stay on.
There will be no images because the mainboard has been disconnected.
If the screen seems faded or intermittently turns black then there's a problem with the TV LED backlights or the power board.
Be safety aware: There is exposed lethal AC voltage on the power board. Disconnect the power to the TV before working in the back of the TV.
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Thank you for your response. The TV appears to have only one board (motherboard and power board in one). After taking off the back cover and trying to turn on the TV the image came on fine. Turned it off and on several times and it still came on fine. The issue happens randomly. This is a picture of the back of the TV with cover off https://imgur.com/a/KMDsP3I
My mistake
I looked online and found the power board for a UN55TU7000BXZA and I assume that you have a UN55TU7000FXZA - you didn't post the full model number ;-(
Removing the back cover and it works OK might be due to either a loose connection that moved when you removed the cover and now is OK until you handle the TV again or perhaps a heat problem.
Intermittent problems are hard because unless you can make it happen you have to wait and then when it does try some things to see if you can make it work or make it fail again.
Try using the TV with the back cover removed for a while and check its performance.
If it doesn't happen it may be heat related and there's enough cooling now so that it won't
If it does then it's something else. Disconnect the power and check the cable connections on the board etc are OK also disconnect the power and check the ribbon cable ends for corrosion etc.
Yes, you are correct it is the UN55TU7000FXZA. Yesterday I had the TV on for hours with the back cover on and the issue did not happen. This morning when the issue happened again I was moving the TV around and out of no where it started working again. So it makes me think it is a loose connection, right? I will leave the cover off and the TV on as recommended but I don't think it has to do with a heat issue based on the TV being on for hours yesterday with the cover on. When I moved the TV around today and the picture come on fine it did go back to having the same problem. Do you think it is likely a loose connection on the ribbon cable?
Hopefully it is on the cable where you can get to it and not on the cable to the screen where you have to disassemble it to gain access.
When (and if) the screen goes black, try shining a flashlight at an angle close to the screen and check if you can see images.
They will be very faint if they're there so trying in a darkened room may help to see them.
If they are visible then it's a backlight problem.
Can't see it too well but in your image there's a cable with a red plug on the right side of the board which I think goes to the backlights (does it disappear into the back of the screen?).
Check the board end connection and if it is OK and the TV does fail again then you have to trace where the cable goes i.e. disassemble.
Thanks I will update if it happens again. Regarding the flashing the screen, when the issue happens I can still see the picture and images clearly but it it is dim (see original picture). And yes the red cable disappears into the screen.
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