samsung un46eh5000fxzc

[smuddge]

samsung un46eh5000fxzc

symptoms are black screen.
samsung start up sound is there.
i can hear audio
the screen has no back light. with flashlight i can see a picture
is this a power supply/inverter issue with this tv?
power supply makes a weird hissing sound for a few seconds when i turn it on.
sounds like it is coming from one of the transformers on the board.


power supply has no bad caps etc.
bn44-00667A is part number for power supply
don't know what i should be testing for voltage on this tv.

[CapLeaker]

Re: samsung un46eh5000fxzc

It is very likely that LED in the back light is shorted. You would have to disassemble the whole LCD to get at the LED strips.

[smuddge]

Re: samsung un46eh5000fxzc

I have never take apart tv that far. is it hard to get to the strips

[CapLeaker]

Re: samsung un46eh5000fxzc

I don't know if you are comfortable taking one apart or not. There are youtube videos on how its done.

[mmartell]

Re: samsung un46eh5000fxzc

Weird that the led driver isn't shutting down the supply ?

[CapLeaker]

Re: samsung un46eh5000fxzc

It does shut down the LED driver circuit, but not the rest of the voltage rails.

[mmartell]

Re: samsung un46eh5000fxzc

I ask because in earlier model Samsungs it kills all the supplies.

[R_J]

Re: samsung un46eh5000fxzc

I just looked at one of these Samjunks, The led voltage at the plug is around 210 volts unloaded with the set on.
I opened the panel and there was one shorted led and 3 open leds. The one shorted led was on the 5 led strip, the open ones were on the 6 led strips.
The led's can be checked by pushing your meter (set to diode test) probes through the white paint to contact the copper trace, this eliminates removing the lens from each led to check them
the 5 led strips can be checked by supplying them with about 12 volts accross the plug that connects to the 6 led strip

[smuddge]

Re: samsung un46eh5000fxzc

ok I will open it up.
wish me luck.
I am using a pool table for a work bench so I hope i don't crack the screen.

will post back.

also where can i get replacement led's if in fact that is the problem

[smuddge]

Re: samsung un46eh5000fxzc

ok i got this thing open but i have no idea what to do next.
i managed not to break anything so im happy with that.
i just don't know where or how to test these with 12v.

here is a pic of what i am looking at.
hopefully R_J you can direct me a little bit more.

thanks so far for all the help

[R_J]

Re: samsung un46eh5000fxzc

I salvaged diodes from a led strip from another led tv with a broken screen. Do you have a meter with diode test?

[budm]

Re: samsung un46eh5000fxzc

Make sure all the connect on each strip is seated properly.
Look real close at each LED, you may see one or more that has turn brown or black.

[smuddge]

Re: samsung un46eh5000fxzc

ok went through each strip. 2 bulbs do not light. both are on 6 bulb strips. both are first bulb in the strip near power connectors top 2.

Anywhere i can buy a couple of replacements?

How do you remove them off the board

[R_J]

Re: samsung un46eh5000fxzc

Now thats where the fun comes in. I have not sourced any new led's I have been using ones off other strips. First remove the lens (its glued in 3 spots) I used a hot air source to heat the strip from the bottom and when the solder melted I removed the led. I used the same techneque to remove one from an old strip, then applied some flux to the solder pads, placed the led on the pads and again heated the area from below making sure the led was positioned properly and correct polarity
I found that heating the led directly causes it to fail or disintegrate.
once the are replaced check for proper operation, once they are working you can glue the lens back on, a dab of crazy glue on each of the 3 legs should hold it in place.
Samsung part numbers are: BN96-28768A (6 led) & BN96-28769A (5 led)

[smuddge]

Re: samsung un46eh5000fxzc

Fantastic.

Thanks for all the help on this one.

I actually found a guy selling the whole set on ebay for 25$.
I ordered them and I guess now I will have some spare leds for the future.

You were a fantastic help for me.

will report back after I get the new strips delivered and installed.

Again thanks very very much for you help!

You are a very valuable member of this community!!

[smuddge]

Re: samsung un46eh5000fxzc

just wanted to report back and say it was infact the 2 leds that were the problem unfortunately on top of that there is tab bonding problems on this tv too. There are both vertical and horizontal lines and a dark band through it. touching the tabs on the side and the bottom left hand side clear it up a bit but not totally and not enough to use or sell it. I did notice when i was putting it back together there was some masking tape rolled up under 2 of the tabs that I didn't notice before so someone else worked on this tv. Likely blew the leds while doing what ever they were doing. crappy but Live and learn i guess. only out 25$ but I learned a lot so it was worth it for me.

thanks again.

parts going up on ebay now i guess.

[R_J]

Re: samsung un46eh5000fxzc

On these sets there are usually 4 pieces of tape that hold the diffuser plastic in place, they are normal and most likely used during assembly.

[GuyTV]

Re: samsung un46eh5000fxzc

I have a uneh5000 in the shop with LED problem. To test the strips, you must disconnect the right from the left side. You can test the far end section (5-led) by feeding 13.5 volts with a 100-ohm resistor in series. For the 6-led strip, you must short the disconnected ends together & provide extra voltage to run this strip. My dc supply only goes up to 13.5 volts. So, I use two 9-volt battery in series with a 100-ohm current limiter in series , that will light up the strip if it's good. (Just make sure not to over feed the supply voltage)
Count the leds, multiply by 2.5v (for ex 5x 2.5v=12.5v.)Start with this voltage & gradually go up, 3 volts per led shall be MAXIMUM to light up any kind of strip.Do not over-feed as you may burn out the strip.
GuyTV

[Louis82]

Re: samsung un46eh5000fxzc

Hello there,

Since is very hard to find the whole led strip at this time for this tv (UN46EH5000) , have you guys had any experience on replacing the individual LED diode? Do you know the specs or any kind of info.

I purchased LED's from China and not sure if they will work or last. LED Backlight 1210 3528 2835 1W 100LM Cool white LCD Backlight for TV TV Application 1W-350Ma Cold white CCT:7000-10000K

Or also I have scrap led strips from the UN50EH5000, wonder if it could work on this 46" tv.

Thank you

[102mm]

Re: samsung un46eh5000fxzc

Guess it's time for these sets to go out.. I have 2 in my shop for the same issue