mrtek
Senior Member
Last Activity: 07-21-2025, 08:22 PM
Joined: 10-28-2010
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...and still working... -
Samsung UN43NU6950FXZA No power
Hi
Picked up another TV. Samsung UN43NU6950FXZA. No power and no standBy led on. Removed back cover and:
Main fuse = OK
Back light LED = OK. Power them with aux power source
LED output = OK 156V
I do get 12 V DC out of the power supply going to the digital section but no 5V or 3.3V. PS_on voltage is only 1.8V. I have looked everywhere on the PCB , I could not find i reference for 5V output.
Also removed connections to panel, speakers and remote but no luck. One strange thing is that even with the LED power supply working, backlight LED do not turn on... -
Thank you for the info....Leave a comment:
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TV has been working every single day. Every day turn it on and at night I shut it off....Leave a comment:
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I would apply the tape method on the right side and see what happens. I did the same thing on my 50 inch Samsung.
https://www.badcaps.net/filedata/fet...3&d=1752628126...Leave a comment:
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After further inspection I have noticed that maybe some components are missing from this device on the bottom side of the board close to the connector that carries signal to the power supply.
can anybody help me confirm if those locations are filled? what about the value ?
Thank you
Massimo...Leave a comment:
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Can you please show how the buffer boards are connected? I am assuming there is only one flex cable. You can apply the tape method on either end of the flex cable. I had similar situation with a 65 inch Samsung TV....Leave a comment:
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New update.
I was ready to read the voltages / signals at the testpoints listed before. So I removed the end of the flex cable going to the faulty buffer board. Turned TV on and at the VGH test point I was reading 24.6V to -6.95V. It was fluctuating between these 2 voltages. Then I remembered that some Samsung have a feedback signal coming from the left and right buffer boards feeding into the T-CON circuit....it is a closed loop. Plugged the flex cable back with no tape applied expecting the TV to fail / not turning on. To my surprise the TV turned on and the screen showed the QLED...Leave a comment:
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You are probably correct. One of the test points is VGH...I can't imagine that signal is dead , otherwise the whole TV would not work. I would have to check the signals with and without the tape applied on the flex cable....Leave a comment:
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Sorry this is the image of the wrong buffer board....Leave a comment:
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Did you remove the cable connecting the buffer boards instead of the cables marked in the image?...Leave a comment:
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Lotas, after a second look , I did find some components that look like protection diodes.
The circled components are the one that are connected to the pins that I have masked with kapton tape.
The test points in question ( LC2, LC1 and VGH) are not shorted to ground. Should I try to remove one of them tomorrow and see if the TV will turn on with only 2 pins covered with tape? I just do not want to make it worse BTW the marking on one of them seems to be S06 or SC8...under the microscope they look like diodes, very tiny..could not find a datasheet for them....Leave a comment:
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I know, I have researched these main boards and they go for $150 Some companies offer BGA reflow services but it looks like to me that my board has been worked on.
How hot these heat sink get? I have seen a guy placing a fan on top of the bga heat sink thru a cutout in the rear panel. He claimed it worked. I am sure it would help but for how long , is the question....Leave a comment:
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Vizio M65-C1
Hi.
picked up another TV. This time is a Vizio M65-C1. TV does not turn on. I had repaired another 60 inch vizio , Bad main board.
When power button is pressed, the Power led indicator on the bottom right, turns for a few seconds and then it fades away. No backlight or Vizio logo on screen. Removed back cover and repeated test.
This is the TV This TV is a little different from the Samsung I have worked on. Power supply is on the Left side, Main Bd is on the right side, T-CON , not in the picture is on the bottom. I am assuming that the boards in the middle are the LED... -
Hi Lotas
I removed the TV back cover and I did not see any protective diodes on either side of the buffer strips. The image is from the end of the buffer strip where the tape solution was applied.
...Leave a comment:
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it is very hard to see them..but right now I am waiting to see if the TV will fail like the first time....Leave a comment:
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did not have time to check. TV has been running for 2 days now with no problem....Leave a comment:
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I did not see any. I will look again....Leave a comment:
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Thank you for the info.
Yes the picture quality is not perfect but unnoticeable when viewing a TV show. More noticeable when using the TV as a PC monitor.
Unfortunately the Main to T-con is one cable only. The T-con is embedded into the main. I should have taken pictures before putting the cover back. Also I could not find a match for my TV type. The TV has been running all day with no failure. We will see what happens. ...Leave a comment:
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Hi Davi.P, I am originally from Alessandria but moved to the US in 1982
Massimo...Leave a comment:
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