Samsung backlight problem


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Samsung backlight problem

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Buppy
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Jun 27, 2017, 6:25 AM

Post #1 of 4 (1555 views)
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Samsung backlight problem	Can't Post

Hi, I'm hoping someone can help with this issue.

I have a Samsung model UN46H6203AFXZA. While watching it, I heard a pop/crack noise, like an electrical short, and the picture went out. Sound stayed on, like nothing was wrong. Tested with flashlight, and menus are visible, so I believe it is a backlight problem.

I was able to find a replacement power/LED board (part# BN44-0771A L46HF_EDY) for cheap, so I swapped it out. As soon as I plugged the power in on the new board there was another pop much like the original, and the TV still has the same symptoms.

Nothing on either board is visibly blown, nor is there any burned electronics smell to it.

I am hesitant to replace the LED strips @ $70+ without knowing that will fix it, especially if I also have to find another power board. Could faulty strips cause the symptoms I have? And does that mean I'd have to replace the power board again? Is there some way to test the board? Or the LEDs without buying a tester? (I do have a multimeter and a variable power supply (up to 30v/10a), but I haven't been able to locate a technical manual to even know what to look for.)

Thank you for any help you can offer.

jts1957
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Jun 27, 2017, 4:27 PM

Post #2 of 4 (1543 views)
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Re: [Buppy] Samsung backlight problem [In reply to]	Can't Post

Shop Jimmy regarding PS/LED Drive board:

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PLEASE NOTE: The LED strips in the models listed are prone to failure. If this board does not fix the problem with your TV, it is likely that you have defective LED strips.

With all else connected normally, unplug CNM803 and see if LEDs light, and stay lit. If not:

Carefully disassemble panel. Disconnect strip you want to test. Set external power supply for 3 - 3.5 volts per LED (ie 30 to 35 volts for a strip of 10) and connect to + and - at the pins of the connector. All should light and stay lit for as long as you have voltage connected.

Remember to reduce back light intensity control setting to prevent a repeat failure.

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Buppy
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Jul 16, 2017, 4:24 AM

Post #3 of 4 (1489 views)
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Re: [jts1957] Samsung backlight problem [In reply to]	Can't Post

Tested the LED strips and many were indeed bad. I was finally able to get some new LED strips, installed them, and now I get a picture. However, it is very dim.

Neither the brightness nor backlight settings change the picture at all.

I've verified that all LEDs are lit. Same issue with two different PS/LED boards. No noticeable difference in LED brightness with CNM803 disconnected.

Any ideas?

Thank you again for any help.

jts1957
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Jul 16, 2017, 8:24 AM

Post #4 of 4 (1488 views)
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Re: [Buppy] Samsung backlight problem [In reply to]	Can't Post

You did obtain a third board (which did NOT pop with the new strips installed)?
Also re-examine all connectors.

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