Lg smart tv 47ln5700 HELP WITH BAD LEDS.

**mattstolte** · 04-23-2015, 09:02 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

What is ha? what is ir?

**newtothis** · 04-23-2015, 09:15 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

HA = Hot Air

IR - InfraRed

**johnboy1313** · 04-24-2015, 05:48 AM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

Can you please post a clear close up pic of a few of the LEDs on one strip? Sometimes there are test points on the strip. Sometimes you can scratch the white paint away a bit to expose some of the trace underneath. I've even had success clamping a sewing needle into each test lead on my meter and using them as very tiny probes to slide under the plastic cover on the LED. If I can see one picture taken close enough to show about three LEDs I might be able to tell you how to test.

Hell, I might have the strips at he too. I won't be there for about eight hours though.

**johnboy1313** · 04-24-2015, 06:13 AM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

Originally posted by johnboy1313

Can you please post a clear close up pic of a few of the LEDs on one strip? Sometimes there are test points on the strip. Sometimes you can scratch the white paint away a bit to expose some of the trace underneath. I've even had success clamping a sewing needle into each test lead on my meter and using them as very tiny probes to slide under the plastic cover on the LED. If I can see one picture taken close enough to show about three LEDs I might be able to tell you how to test.

Hell, I might have the strips at he too. I won't be there for about eight hours though.

I swiped this pic from eBay. You should be able to carefully scrape the white paint approximately where the red arrows are. Set your meter to diode mode. Red lead on one side and black on the other. If you don't get a reading, swap the leads. If you still don't get a reading, that LED is likely open.

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**mattstolte** · 04-24-2015, 10:46 AM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

Do i have to have power hooked up when i do this?

**budm** · 04-24-2015, 10:51 AM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

No, never do Ohm or Diode test mode with power applied to the what you are checking.
You apply power when you want to measure Voltage and current.

**mattstolte** · 04-25-2015, 06:42 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

Originally posted by johnboy1313

i swiped this pic from ebay. You should be able to carefully scrape the white paint approximately where the red arrows are. Set your meter to diode mode. Red lead on one side and black on the other. If you don't get a reading, swap the leads. If you still don't get a reading, that led is likely open.

johnboy i just spent last 1 hour scrapping off the paint and i checked all leds both sides over every one said 001 on diode mode so im lost now

**mattstolte** · 04-25-2015, 08:03 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

There seem to be test points on these strips but I don't know how to test them. I can get pictures up if that helps

**mattstolte** · 04-25-2015, 08:11 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

I also included a picture of the green board the Leds are attached to is it possible let that is bad? Also on the led strips there are some other single gold test dots

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**mattstolte** · 04-26-2015, 09:34 AM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

Anybody please

**mattstolte** · 04-26-2015, 10:19 AM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

Ok i figured this help with some of your help. I was able to get the leds to light up with diode mode. Man am i learning so much on here. Believe me i know i ask for alotof help but remeber this i learn something new everytime and wont ever have to ask that queztion again. I was able to test all the leds except i couldnt figure out how to test the last led on each string. And i found two leds that wouldnt light up

**stj** · 04-26-2015, 10:30 AM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

how is the lense held over the led?

**mattstolte** · 04-26-2015, 11:52 AM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

I'm not sure what u mean.

**budm** · 04-26-2015, 12:34 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

Originally posted by mattstolte

Ok i figured this help with some of your help. I was able to get the leds to light up with diode mode. Man am i learning so much on here. Believe me i know i ask for alotof help but remeber this i learn something new everytime and wont ever have to ask that queztion again. I was able to test all the leds except i couldnt figure out how to test the last led on each string. And i found two leds that wouldnt light up

So please show us how and where you get to the test points so some other people can see what you did.

**stj** · 04-26-2015, 12:41 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

the plastic bit looks like it's over the actual led.

**newtothis** · 04-26-2015, 12:43 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

Yeah there is a dome cover over the LED that can usually be pulled off

**mattstolte** · 04-26-2015, 03:22 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

Yes the dome can be pulled off is there anything I can do besides ordering new strips and yes I did what johnboy said about scraping the paint but you can't go on both sides of led u have to go on 1 side of the led and cross over to the other. Side of the next led to test each one

**mmartell** · 05-05-2015, 09:49 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

Originally posted by mattstolte

I did what johnboy said about scraping the paint but you can't go on both sides of led u have to go on 1 side of the led and cross over to the other. Side of the next led to test each one

Would you mind elaborating ? I'm trying to follow what you're saying but I can't figure it out. My led strip looks like the pic above by johnboy1313 and I thought the narrow path WAS the trace but he seems to be implying the narrow path is the separation between conductive paths. I'm trying to figure out which of my leds is open. Thanks.

**ScottyDont** · 06-10-2015, 06:53 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

So I just joined this forum and I am pretty well informed on what is out there with LED/LCD problems. I am new to fixing TV's but I am not new to repairing electronics. So I have this TV and have read this entire forum. I decided to take a video of my LG 47LN5700 turning on LEDs only and then freeze the frame when all the lights are on. This is what I got. From what I can tell it looks like two LEDs in the top right R2 strip are out, which is causing the following 3 strips below to not work. Does this seem correct?

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**budm** · 06-10-2015, 07:07 PM

Re: Lg smart tv 47ln5700 HELP WITH BAD LEDS.

Well the top row with two LEDS not on but the strip still lights that means those two LEDs on the top strip are shorted out which will allow the current to flow through the strip to light up the rest of the LEDs on that strip.
The other 3 strips which are not on at all may have open LEDs.
There are 6 LED so there may be 6 LED driver circuit per strip, I cannot really tell until I can trace out the LED driver board connection.
Need to see good clear pictures of your board, but you can also test each LED on those 3 dead strips.

Lg smart tv 47ln5700 HELP WITH BAD LEDS.

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