Samsung 32" power supply BN44-0351B no backlight

[JamesPereira]

Re: Samsung 32" power supply BN44-0351B no backlight

I have the same problem in your model tv, i dont have backlight here is the pcs802s/b? Can you show me by picture? Thanks a lot

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

ok i've bought these leds, 14.62€ includes shipping. we will see if they got same temperature

[diif]

Re: Samsung 32" power supply BN44-0351B no backlight

yes but almost impossible to find. Hope 6500k leds i've just bought got the right temp

Not really.
it.rs-online.com/web/c/display-e-optoelettronica/led-e-accessori/led-visibili/?searchTerm=LM561B

Not data sheet but shows a picture of the bottom of the LED not in the data sheet.

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

I would think they are using their own LEDs in their TVs. Perhaps something like the LM561B.

Well again look at color chart. https://en.wikipedia.org/wiki/Color_temperature
Higher temps are bluer. Trouble is just because they list them as certain temp doesn't mean they are. If you get actual 5700k they will be yellow. I would contact seller and tell them you did not get right temp leds.

yes but almost impossible to find. Hope 6500k leds i've just bought got the right temp

[dskall]

Re: Samsung 32" power supply BN44-0351B no backlight

Well again look at color chart. https://en.wikipedia.org/wiki/Color_temperature
Higher temps are bluer. Trouble is just because they list them as certain temp doesn't mean they are. If you get actual 5700k they will be yellow. I would contact seller and tell them you did not get right temp leds.

[diif]

Re: Samsung 32" power supply BN44-0351B no backlight

I would think they are using their own LEDs in their TVs. Perhaps something like the LM561B.

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

Where did you get the LEDs from ?
Apart from the colour difference they also seem brighter.

yes, exactly. Also the pinout is different. Can't find the exact model of LED installed in the backlight bar. I bought them from ebay.

http://www.ebay.it/itm/10-pieces-OSR...53.m2749.l2649

Now i've just bought these 6500k:
http://www.ebay.it/itm/4x-10x-LUW-JD...53.m2749.l2649

[diif]

Re: Samsung 32" power supply BN44-0351B no backlight

Where did you get the LEDs from ?
Apart from the colour difference they also seem brighter.

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

They look yellow to me. Look at color temp charts. Higher temps are bluer lower temps are yellow

yes, exactly! I bought 5700k as you said, but looks like yellow.
Just bought 6500k...hope to solve the issue.
Anyway the power supply is now working, backlight also...maybe it was a bad soldering problem in the optocoupler.

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

Why not try shorting PCS802S/B (e-c) if the QS801, etc. are ok the tv should turn on.
Or try shorting QS871 e-c to see if the tv comes on
Power on/off controls QS871, If QS871 is turned on it connects PCS802S/A to ground causing its led (in the optocoupler) to light.

yes, shorting PCS802S/B works, backlight is on.So is the optocoupler dead?

[dskall]

Re: Samsung 32" power supply BN44-0351B no backlight

They look yellow to me. Look at color temp charts. Higher temps are bluer lower temps are yellow

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

Bright white which has a bluish tint. So I would say 5700K. Others will give yellowish tint

unfortunately 5700k is too warm, i probably need 6500k.
As you can see in the photo, you can easily find the replaced LEDs.

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

thanks...i've ordered 10 of them, plus a 15V zener because i've lost the small one i've desoldered for testing

[dskall]

Re: Samsung 32" power supply BN44-0351B no backlight

Bright white which has a bluish tint. So I would say 5700K. Others will give yellowish tint

[Moreno83]

Re: Samsung 32" power supply BN44-0351B no backlight

The best thing you can do is google the led strip name!

https://www.vareza-elektronik.de/pro...85&language=en

[Moreno83]

Re: Samsung 32" power supply BN44-0351B no backlight

They are connected in series. If 1 dies , the whole strip is off. ( Christmas lights ).

So in this case it looks like you only need one. Not sure about the lumen , maybe someone else can answer that. Maybe it is in the service manual.....

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

That is a burned LED!

Looks like a Osram Duris E5 LED....

https://www.led-tech.de/en/High-Powe...0_206_216.html

replace the faulty led.

thanks looks like very similar...but which temperature? 2700k? 3000k? 5700k?

and...how many? i suppose that they are connected in parallel, so it's not only one burned.

[Moreno83]

Re: Samsung 32" power supply BN44-0351B no backlight

That is a burned LED!

Looks like a Osram Duris E5 LED....

https://www.led-tech.de/en/High-Powe...0_206_216.html

replace the faulty led.

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

Right now what dcv (in circuit when TV is turned on) do you have between E and B of that Transistor?

with C-E shorted, is 0.15V

Have a look at:-

http://www.ebay.it/itm/152536779696

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