Samsung UA50f Backlight problem

[provider10]

Hi
Got this samsung UA50f I think the a is because i live in south Africa.
This set has 9 rows of LED strips . The top 5 rows come on fully bright but the bottom 4 come on dull. The lights are only on for a second or so then they all switch of . and a relay can be heard clicking. I chaned one of the dull strips with the bright one and still the same so I dont think its the LED strips.
Any help would be appreciated

James

[nomoresonys]

Re: Samsung UA50f Backlight problem

Can you post good clear straight shot pictures of the whole back and each board.

[provider10]

Re: Samsung UA50f Backlight problem

Hope these pics help. I think the model in UK is UN50F

[neilc6]

Re: Samsung UA50f Backlight problem

Check if you have good continuity through the connector. You may also have bad backlights.

https://www.badcaps.net/forum/showthread.php?t=72299

[provider10]

Re: Samsung UA50f Backlight problem

The back lights are good as i changed one of the dim set to a position where they were bright and the leds lit up good

[budm]

Re: Samsung UA50f Backlight problem

You have FOUR LED drivers so you need to check the Boosted Voltage output of each driver when you first turn on the TV.
Your pictures are too blur to be able to read any prints on the boards.

[provider10]

Re: Samsung UA50f Backlight problem

Hope these pictures help. The problem is the set does not stay on long enough to make any measurements

James

[provider10]

Re: Samsung UA50f Backlight problem

sorry pics did not attach

[budm]

Re: Samsung UA50f Backlight problem

You are looking to see how high the LED drive Voltage jumps up to when TV is first turned on, so you will have to repeat the test 4 times to see if they all jump up to the same level or not before the protection circuit kicks in. Set meter to 200 Vdc scale or higher.
What is the power supply board P/N? BN44-?????.
There is Voltage chart printed on the board.
EDIT: I now see the board P/N BN44-00624B.
Can we get good clear straight shot of the whole top and bottom side of the power supply board?