7thkey
Member
Last Activity: 07-19-2015, 10:07 PM
Joined: 06-26-2015
Location: hudson nh
-
I have the same model of LG tv (50ln5600) and possibly the same problem. I'm wondering if I should just bypass all the testing and just buy replacement lights. Can you tell me what the part numbers are and where you bought them? Thanks in advance. -
Re: Backlight issue LG 50ln5600
Replacing that led string fixed it.[ATTACH]115187[/ATTACH]... -
Re: Backlight issue LG 50ln5600
Replacing that led string fixed it.Leave a comment:
-
Re: Backlight issue LG 50ln5600
I may have figured it out. While all my LEDs do light up I noticed one L1 strip was drawing more than the others. Sure enough I switched that strip with the strip on set 1. Now line 2,3,4 light up instead of 1,5,6.
I noticed the extra draw when I was discharging the board in diode mode after TV was off. All the LED s slowly faded at the same rate except that L1 strip it stayed lit longer. So it seems to be just enough to fault and trigger the protection shut off.
Anyway should get the new strip in a couple days. I'll let...Leave a comment:
-
Re: Lg 50 inch no backlights
Do you the backlights light up for a moment when you turn on the TV? I am currently working on a similar issue with a 50ln5600 also just over a year old. My back lights run on 2 circuits. The first runs 1,5,6, in series the second runs 2,3,4 LED strings. On mine 2,3,4 are not lighting with the number 4 circuit not getting enough voltage. On my TV 1,5,6 all light up for a moment at start up. I have not done it yet but I am going to skip the connector board and hard wire them in the next couple days. The voltage on led + is 78 on both like yours.Leave a comment:
-
Re: Backlight issue LG 50ln5600
So you think bypass the connectors all together ? Jump the leads with small wires? Thing is thing is if I take a reading of the green board with no connected LED strips the connection points the 4th connection is the voltage drop.
So you don't think one of the led strips could be bad and still light up?...Leave a comment:
-
Re: Backlight issue LG 50ln5600
So today I measured the voltage on the 4 points on the plug that connects to the thin green led board. Before they enter board they are 78,0,78,0 that seems up to spec. I'm thinking at this point replace all LED strips and that green board. The LED strips may light up fine but if one is triggering the protection shut off.Leave a comment:
-
Re: Backlight issue LG 50ln5600
I did in the start of the post . I measured the 2 led+ and 2 led-. I have not replaced the thin green board yet. That's my next step unless someone chimes in on what would cause one string to get no voltage. I've tried 2 different power supply's.Last edited by 7thkey; 06-29-2015, 07:54 PM.Leave a comment:
-
Re: Backlight issue LG 50ln5600
All strips are good. I have done the diode to ground test and each one separate . Every led lights then fades properly as the remaining voltage is drained. So boost converter? On what board is that as I already replaced the power supply/LED driver board?...Leave a comment:
-
Re: Backlight issue LG 50ln5600
Ya if I put the non lighting LED strings in the 3 spots that light they light up. Clearly position 4 is where the voltage stops. I have tested that strip and nothing it lights up fine in the top spot. So what would cause one string to get no voltage on power up? The green connection board is 6637L-0021A. The power supply EAX64905501 v2.2 was swapped out for another same version I was told was tested and working properly. I guess it is possible I got a bad board but to both have the same LED string out is unlikely. Is it possible the...Leave a comment:
-
Re: Backlight issue LG 50ln5600
[attach]114638[/attach]
[attach]114639[/attach]
[attach]114640[/attach]
3rd pic upside down not sure why sorry.Re: Backlight issue LG 50ln5600
[attach]114638[/attach]
[attach]114639[/attach]
[attach]114640[/attach]
3rd pic upside down not sure why sorry.Re: Backlight issue LG 50ln5600
[attach]114638[/attach]
[attach]114639[/attach]
[attach]114640[/attach]
3rd pic upside down not sure why sorry.Re: Backlight...Leave a comment:
-
Re: Backlight issue LG 50ln5600
Pictures of LED setup.
Second picture shows one set lit 3 sets light up and then go out fast . I have swapped out all LED strips and no LEDs are out.
In the last picture I labeled them 1-6 to show voltage (red x indicates does not light up on start up) the red x LED strips do work though if I swap them.
1) 63v
2) 170-78v
3) 146-55v
4) 50-0v
5) 110v-78v
6) 86v-55v
The first voltage is power on voltage.
The second voltage is the constant it ticks down to and stops at.
Well...Leave a comment:
-
Re: Backlight issue LG 50ln5600
The LED strips do have a + - test points. I believe I can test them in diode mode. I'll try that tomorrow and get some readings. I really don't think its a contact though as I can switch out different strips and they light up in the working rows....Leave a comment:
-
Re: Backlight issue LG 50ln5600
They have a plastic plug in type connector.
This is the direct replacement parts for it.. Each LED string is 2 pieces that attach to one another forming 6 long strings that connect to that board by the same plug in....Leave a comment:
-
Re: Backlight issue LG 50ln5600
I'll get a picture up tomorrow. Each led strip is made up of 2 strips. They are in 6 rows top to bottom. No matter what set of LEDs I swap in. Only the same 3 rows light up then shut off. If I swap the lighting 3 with the non lighting 3 the same three rows continue to light . At first I believed 3 rows of LEDs were bad and needed replaced. I swapped those rows with the working LEDs and they would not light. The LEDs open or shorted does not seem to be the issue. The issue is what would make 3 entire middle rows not light up if the LEDs on those rows...Last edited by 7thkey; 06-28-2015, 01:10 PM.Leave a comment:
-
Backlight issue LG 50ln5600
I have an issue with 3 backlight strings not lighting. I turn TV on top 2 strings light, bottom string lights. Middle 3 do not. Then all backlights turn off due to protect . I tried switching out different working stings to result in always the same result. This model has the led drivers built into power supply. I replaced power supply also same result. I do have picture and sound via flashlight test.
From top to bottom led+ 108 to 78, led- 40, led+ 170 then slowly drops,led- 61.
I have not replaced or tried a bypass jump of main board. I have not replaced the led... -
Re: New Members - please post your introductions here
Well I have a 2 year tech degree from Keene state college . From there I never really pursued that though. I mostly repair and build personal PCs. However for friends and family I do some small electronic repairs. Found this site very informative and helpful.Leave a comment:
No activity results to display
Leave a comment: