SAMSUNG led un32eh4003f Plays melody No picture & led blink

[budm]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

"1 - 211v - D+
2 - 189v - S-
3 - 0v - N/C
4 - 191v - S+
5 - 0v - D-"

One thing that is bugging me is that looking at the bottom side of the board, pin 2 is connected directly to pin 4, so the reading on pin 2 and pin 4 should be the same unless the trace I see in the picture is not what it is on the board.
But any way I traced out the board and draw up simplifed circuit.
You are getting 0V on pin 5 which cannot be normal, it should show Voltage there on pin 5 if the LED strings are not open.
Pin 5 is the return line through the PWM controlled Power MOSFET (Q9803) and the current sensing resistor (R9803) for maintaining constant current through the LED strings.

[mangus580]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

So that would suggest an open LED circuit, correct?

[budm]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

Yes, and I want to verify for sure that I am correct by testing each one to find out.

[mangus580]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

Ok, I dont have an easy method for testing each LED. I am not even sure how easy it is to get to each individual LED.

Talking with a friend of mine today telling him of my project.... He suggested I try using an ammeter from D+ to D-

He said this should show me a constant current essentially replacing the LED strips as far as the power supply is concerned.

So... I tried that. I got a flicker on the meter briefly, but it went back to 0.

Using his concept, it would say the power supply is the issue...


Thoughts?

In the end, I am sure we can agree, that its either the power supply or the LED strips. Since replacing both keeps me under my budget for fixing the TV, I am not opposed to replacing both.... But I would prefer to make a well educated guess as to which is needed.

Thanks again,
Mike

[budm]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

Using amp meter like this?
https://www.badcaps.net/forum/showpo...4&postcount=95

Or using indicator:
https://www.badcaps.net/forum/showpo...&postcount=107

If the bad LED is not completely open but has high resistance then you may see very little current flowing through the string but not enough to light up the LEDs.
I would get the strips first and see what happen.

[mangus580]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

I ordered the LED strips - and they should arrive tomorrow - I will update you with what I find...

[mangus580]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

All better!!!!!

Thanks!!!

[tom66]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

Good to hear, shame to see yet another set taken down by bad LEDs though.

[budm]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

Thanks for the follow-up, BTW, how did you get the part so fast?

[mangus580]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

I paid the extra $4 for 2 day shipping.... I figured it was worth it to not have the tv apart in my office any longer than needed.

Tom, I was smart, I am keeping the old strips too. I am figuring only one strip was bad, and if it happens again, its likely to only be one... guessing maybe I can swap strips around to find the good ones at a future date if needed!

[Caleb]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

I just got one of these today, on my bottom led strip are 3 dead and the top wont light at all, Has anyone had any success pulling leds from another dead board and replacing them? I dont have any other samsung led panels but Ive got a bunch of other led strips from broken screen sets. May just end up trying to Frankenstein another backlight into the panel, I looked around online and the only ones in stock would cost 60$ plus shipping.

[mangus580]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

I just got one of these today, on my bottom led strip are 3 dead and the top wont light at all, Has anyone had any success pulling leds from another dead board and replacing them? I dont have any other samsung led panels but Ive got a bunch of other led strips from broken screen sets. May just end up trying to Frankenstein another backlight into the panel, I looked around online and the only ones in stock would cost 60$ plus shipping.

These are the LED's I used:

http://www.shopjimmy.com/samsung-cy-...s-2-strips.htm

worth every penny! the tv has worked awesome ever since.

[Caleb]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

If only they had them in stock.....they have set a fair price. Everyone else has set a rather high price point. I have several sets with leds that look identical. Not sure if they would be compatible or not. Pulled a set from a 32 insignia tonight to check and see if I can pull individual LEDs. The lenses appear to be glued on top of the diodes. Does master Budm have any suggestions for removing them without destroying them?

[mangus580]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

If only they had them in stock.....they have set a fair price. Everyone else has set a rather high price point. I have several sets with leds that look identical. Not sure if they would be compatible or not. Pulled a set from a 32 insignia tonight to check and see if I can pull individual LEDs. The lenses appear to be glued on top of the diodes. Does master Budm have any suggestions for removing them without destroying them?

You could try contacting shop-jimmy to see when they estimate stock returning....

I kept my old strips - not knowing if one strip is still good.

[thoma]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

http://www.ebay.com/bhp/led-backlight-strip

Here are a lot of LED Stripes for Backlightning LCD TV

[lordkev]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

How did you guys actually get at the LED strips? I have a similar model UN40H5203AF and I could see them if I took off the front bezel and separated the panel. However, I imagine I'd want to go in from the back somehow to replace them?

[Caleb]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

You have to completely dismantle the panel, they are under the glass and the diffuser. Both of which will show dust and dirt if you get them dirty, the glass is very thin and the ribbons fragile, this tv has no screws just a bunch of clips. Work your way slowly around the bezel popping the clips loose with your fingernail. Then gently remove the glass and diffuser then you can finally access the led string. It would have made them way too easy to replace if they had placed them in from the back.

[keithwyatt533]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

Hi,

I have the same model and I've checked all of the LED's and they are on but don't seem very bright. I can see the picture but it is very dark and I can't make it any brighter with the brightness/contrast/etc adjustments. What should the voltage be on pins 1/2 and 4/5? I get 22.4 V on each set with pin1 to chassis - 152V, Pin 2 - 129V, pin 4 - 129V and pin 5 - 107V. Any help would be appreciated.

Thanks

[budm]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

How about the BACKLIGHTS LEVEL adjustment, it is not the same as the brightnees adjustment.
http://downloadcenter.samsung.com/co...0526105716962/[UE4003-ZA]BN68-04459A-02ENG-1014.pdf

[keithwyatt533]

Re: SAMSUNG led un32eh4003f Plays melody No picture & led blink

Adjusting the backlight also has no effect.