Samsung UE49MU6120K works then off/lines/flickers

[Fixing222]

This is strange it worked almost everytime the last 6 times for around 4 hours then it fades slightly and powered off and then quite quickly powers on and off while there is flickering and horizontal or vertical lines.

Today I went to watch it and it didn't even give me the 4 hours then I take a break for 30 min and it works it went straight to dim backlight then lines on TV then off and on etc.

Any ideas main board or powerboard or possibly something else?
I took voltages on powerboard to the main board that were meant to be 13v I think we're 12.7

To add I did feel heat and smell something I can't remember what it smelled like while it was on. Now I opened it the heat I'm sure was from the powerboard area. Maybe normal but don't feel that in my Sony set.

[nomoresonys]

Re: Samsung UE49MU6120K works then off/lines/flickers

First guess would be mainboard fault, here's how you test those voltages at the connector going from powerboard to mainboard: Test connector from mainboard to powerboard on powerboard side with all boards hooked up, test with tv plugged in but off then hit power, report both conditions here, give pin number, pin description/name and condition both off and when you hit power on. So we can see all the voltages and what they are doing. Try to do test just as instructed, example in second link below if needed.

[Fixing222]

Re: Samsung UE49MU6120K works then off/lines/flickers

First guess would be mainboard fault, here's how you test those voltages at the connector going from powerboard to mainboard: Test connector from mainboard to powerboard on powerboard side with all boards hooked up, test with tv plugged in but off then hit power, report both conditions here, give pin number, pin description/name and condition both off and when you hit power on. So we can see all the voltages and what they are doing. Try to do test just as instructed, example in second link below if needed.

I get 12.7v on them and the ground are -0.002 but could a bad main-board cause it to turn on and off repeatedly?

[nomoresonys]

Re: Samsung UE49MU6120K works then off/lines/flickers

It could, you need to test all the pins, the pictures are too out of focus to see the labels and such.

[Fixing222]

Re: Samsung UE49MU6120K works then off/lines/flickers

It could, you need to test all the pins, the pictures are too out of focus to see the labels and such.

Not sure what you mean pin number (Maybe CNM803)
Incase anyone has similar here is a video of my TV fault
https://vimeo.com/354973411
From the top of the TV down these were the readings from the powerboard side
3.18
12.79
12.79
12.79
12.79
-0.007

Temps were taken in standby
Unfortunately I can't test with the TV off standby as of now for some reason it's decided not to turn on now only red standby tried button and remote

[nomoresonys]

Re: Samsung UE49MU6120K works then off/lines/flickers

With tv unplugged from power, unhook cable from powerboard to mainboard, plug tv into power, see if backlight comes on and stays on.

[budm]

Re: Samsung UE49MU6120K works then off/lines/flickers

What happen if you remove the two white flat ribbon cables on the main board that go to the LCD panel integrated T-CON board, does the TV still power off and comes back on by itself?
BTW, inspect the female connectors of the cable that goes between Main board and power supply too for any sign of heating.

[Fixing222]

Re: Samsung UE49MU6120K works then off/lines/flickers

With tv unplugged from power, unhook cable from powerboard to mainboard, plug tv into power, see if backlight comes on and stays on.

Tested and yes it comes on and stays on.

What happen if you remove the two white flat ribbon cables on the main board that go to the LCD panel integrated T-CON board, does the TV still power off and comes back on by itself?
BTW, inspect the female connectors of the cable that goes between Main board and power supply too for any sign of heating.

When tested the same thing happened off and on i could see backlights flashing and dimming etc like before. But i will check those cables in morning as i didn't check.

[nomoresonys]

Re: Samsung UE49MU6120K works then off/lines/flickers

Disconnect the power cord from the outlet, then press and hold the power button on the TV (not the remote), for 30 seconds. Then wait a few minutes and plug the TV back in and press power once, variation could be hold power button while plugging in.

[nomoresonys]

Re: Samsung UE49MU6120K works then off/lines/flickers

Looking like a mainboard issue.

[nomoresonys]

Re: Samsung UE49MU6120K works then off/lines/flickers

Not sure if any of these will work, some resets to try: While the TV is On, press and hold the EXIT button on the Samsung remote control for 12 seconds. The standby light should blink the entire time without interruption.
The Factory Reset screen displays a warning message. Select OK to reset the TV.

[nomoresonys]

Re: Samsung UE49MU6120K works then off/lines/flickers

Could be a panel problem.

[Fixing222]

Re: Samsung UE49MU6120K works then off/lines/flickers

Not sure if any of these will work, some resets to try: While the TV is On, press and hold the EXIT button on the Samsung remote control for 12 seconds. The standby light should blink the entire time without interruption.
The Factory Reset screen displays a warning message. Select OK to reset the TV.

Ok worth trying i will try some out and see if anything, thank you.

[nomoresonys]

Re: Samsung UE49MU6120K works then off/lines/flickers

If your lines look like this, here's a good explanation of what's wrong and how to check, usually requires some disassembly, BE EXTRA CAREFUL whenever near the panel, they're very flimsy and easy to break, if it breaks it's game over: https://www.youtube.com/watch?v=LysMj2Tcp4M

[Charleyd]

Re: Samsung UE49MU6120K works then off/lines/flickers

First step after opening a TV: Check that all screws that attach all of the circuit boards are tight. In your case, would recommend removing the main board and cleaning the mounting pedestals on the chassis with fine steel wool and cleaning around the screw holes in the circuit board with a pencil eraser. Then reinstall main board with screws tight. This solved a similar problem with a Samsung for me.

[Charleyd]

Re: Samsung UE49MU6120K works then off/lines/flickers

Oops - looking back at your pictures, I see that your circuit board mounting type is without screws, so I guess that my suggestion won't help you. Still a good general rule to check the mounting screws.