Samsung UN32F5500 with bad LEDs

[jts1957]

Re: Samsung UN32F5500 with bad LEDs

1) People 'lie.'
2) Check backlight controls and reduce any that are set at 100%.

[thoma]

Re: Samsung UN32F5500 with bad LEDs

@jts1957
'Diode' has TWO solder joints.
'Lens' has THREE points securing.

What do you mean with lens three points securing
are there 2 points for anode or cathode and one for the other?
Can you please explain this!
regards thoma!

[caphair]

Re: Samsung UN32F5500 with bad LEDs

@thoma

Led has normal two leads soldered. The lens that's placed over the led is secured in place at three points.

[thoma]

Re: Samsung UN32F5500 with bad LEDs

I know Led: Anode and cathode! is the third pin the lens mounted to ground
or connected with Anode or cathode?
I hope you know what I mean !Hope my Question is not stupid!
regards thoma!

[caphair]

Re: Samsung UN32F5500 with bad LEDs

Anode

[caphair]

Re: Samsung UN32F5500 with bad LEDs

What I would like to know is how these are wired in series? Is each string being fed the same voltage from the strip on the side and they just tap in?

[budm]

Re: Samsung UN32F5500 with bad LEDs

The one in my pictures, each LED PCBA has 9 LEDs connected in series, then each PCBA are connected in series to form on big lonG LED string, that is why when one LED goes open circuit then whole string will no longer light up.
There are only 2 pads/connection for each LED as you can see here:
https://www.badcaps.net/forum/attach...3&d=1431830352

[jts1957]

Re: Samsung UN32F5500 with bad LEDs

@jts1957
'Diode' has TWO solder joints.
'Lens' has THREE points securing.

What do you mean with lens three points securing
are there 2 points for anode or cathode and one for the other?
Can you please explain this!
regards thoma!

Lens has NO electrical contacts. Has three plastic pins that go through the board and are melted / crimped over from back side to secure.

[thoma]

Re: Samsung UN32F5500 with bad LEDs

Thank you to all!
@budm it is like in the real life a picture says more than thousend words!
regards thoma!

[caphair]

Re: Samsung UN32F5500 with bad LEDs

Does anyone know if most manufacturers are using the same LEDs? Are there replacement LEDs available anywhere?

[budm]

Re: Samsung UN32F5500 with bad LEDs

These may work:
http://www.digikey.com/product-detai...8CT-ND/3748977
http://www.digikey.com/product-detai...7-1-ND/2164128
http://www.digikey.com/product-detai...8-1-ND/2164129
http://www.digikey.com/product-detai...7-1-ND/5731650




The 50~60mA rating will be too low, most of them run in 100mA range.
I did not order one of these to try yet to see how it works.
Edge lit may use OSRAM, not sure.

[caphair]

Re: Samsung UN32F5500 with bad LEDs

Which ones have 50-60ma rating? Specs all said over 100ma max no?

[budm]

Re: Samsung UN32F5500 with bad LEDs

Which ones have 50-60ma rating? Specs all said over 100ma max no?

50~60Ma will be too low, that is why the examples are over 100mA range.

[Alastair E]

Re: Samsung UN32F5500 with bad LEDs

I had a Technika--With a 40" Samsung panel--Exactly same layout with the LED's but the LED Driver-board is Inside the display-panel!

One LED was O/C, and two were S/C

These fixed--and yet another couldn't decide whether it was faulty or not--as it kept flashing at me!

I chopped up an LED strip/string I rescued from a similar design LG panel and using double-sided tape, stuck individual LED's in place over the dead LED--after its lens and SM chip had been ground away.

Lot of time and messing round--but sorted the problem.

[ReeceyBurger123]

Re: Samsung UN32F5500 with bad LEDs

I had a Technika--With a 40" Samsung panel--Exactly same layout with the LED's but the LED Driver-board is Inside the display-panel!

One LED was O/C, and two were S/C

These fixed--and yet another couldn't decide whether it was faulty or not--as it kept flashing at me!

I chopped up an LED strip/string I rescued from a similar design LG panel and using double-sided tape, stuck individual LED's in place over the dead LED--after its lens and SM chip had been ground away.

Lot of time and messing round--but sorted the problem.

What panel was it LTA400HM23 ?

[caphair]

Re: Samsung UN32F5500 with bad LEDs

Would these work universally possibly?
http://www.ebay.com/ulk/itm/261436600000
http://www.ebay.com/ulk/itm/381477582411

Not exactly sure what to look for for replacements. Do LEDs used in tvs have a part #?

[Alastair E]

Re: Samsung UN32F5500 with bad LEDs

You need to look for 0.5W cold-white chip LED's They are 3.3V and 150mA nominal.

[caphair]

Re: Samsung UN32F5500 with bad LEDs

Budm is this tv still working? I'm curious the longevity of the LEDs after a couple fail.

Also, could you use a resistor to simply replace an open led just to get the string going again?

[budm]

Re: Samsung UN32F5500 with bad LEDs

I am still using it on my test bench to dvd and Video sources.
I did not have a chance to try out the resistor in place in this Samsung.
One thing is that the LEDs are driven by constant current source and the Vf on the LEDs will basically stay constant at around 3 ~3.3V, so when using the resistor in place when the current is reduced or increased the Vdrops on the resistor will vary with the amount of current so the total Vf of the string will vary and this may be detected by the protection circuit.

[reyronaldo]

Re: Samsung UN32F5500 with bad LEDs

Four (4) IN4007 diodes in series would be enough instead of 5, if you plan to have a 3.5v drop for every busted LED. Four diodes in series would be equal to 4 volts because each diode consumes 1 volt as forward voltage, so, 4 x 1 volt =5 volts. However, to be safer, if you don't know the exact voltage requirement of each LED, I suggest that you use 6 IN4007 LEDs = 6 volts for every busted LED for any brand of TVs. A TV backlight is usually rated at 3-6 volts. The current will have a maximum of 1000mA or 1A for a series of diodes (regulated), since, the maximum rating of IN4007 diode is 1A which is safe enough for the common 200-500mA current supply by the TV LED driver. Hope this helps. Any suggestion?