LG 42LA6130 did not turn on

[magicpc]

Hello I apologize in advance for my language - I use the translator.

I have a problem with my xxx tv. At the beginning, when I tried to turn it on, the red LED flashed 3 times and silence. I read on the internet that this is a power supply that I replaced with a working one.

After replacing the power supply, the problem was the same, but after a while the TV went out and there is no red LED anymore.

Can you suggest how to diagnose it? I am a beginner and I am just learning.

In the photo below, I tried to emphasize what the voltage situation on the power supply board looks like.

The voltage on the fuse is sometimes 180V and sometimes 24V

Tomorrow I will check if I entered the tensions correctly.

Power supply: LGP42-13PL1

[neilc6]

Re: LG 42LA6130 did not turn on

LA series is similar to LN series which has high rate of failure of LED backlights. Your original power supply likely was turning on with the backlights shutting down into protection mode or an open circuit. You typically get a flash of backlights but they won't flash if open circuit. I would put your original PS in and measure the voltages driving the LED. If they are high and close to the rated voltage printed on the board, this will indicate you have an open circuit in the LED string. The front LED flashes when the TV is booting up and will be off when the TV is on. With the backlight shut down and TV on, you can google tv flashlight test to confirm you have an image.

[magicpc]

Re: LG 42LA6130 did not turn on

Thank you for the quick reply. The problem is I connected the primary power supply and the red led blinked and it's still the same. (it did not flash on the new one except for the first time)

I moved a few emollients to a new power supply, but that didn't change anything.

I probably still have a working power supply with the number LGP474950-14PL2. Can i go somehow?

[dskall]

Re: LG 42LA6130 did not turn on

Need a good picture of your power supply. Use the "go advanced" option.

[magicpc]

Re: LG 42LA6130 did not turn on

I hope that was it.

I took a chance and connected another motherboard and power supply. Now you can see the LG logo but the backlight is blinking. It flashes every 1 second.

[nomoresonys]

Re: LG 42LA6130 did not turn on

start with touching up the solder joints, looks like at least a couple bad ones, examples of bad joints there: https://www.google.com/search?q=bad+...h=578&dpr=1.25

[nomoresonys]

Re: LG 42LA6130 did not turn on

if that don't do it, it's probably just the usual backlight issues as mentioned.

[magicpc]

Re: LG 42LA6130 did not turn on

I will improve the connections on the old power supply. On a different power supply and motherboard, the situation looks like the picture below.

[nomoresonys]

Re: LG 42LA6130 did not turn on

ok, you have it stripped down to backlights, you can test them, just look up diy backlight tester on youube if you don't have one, don't test them with tv plugged in or powered if your testing with tester, can also test them individually with multimeter probably.

[magicpc]

Re: LG 42LA6130 did not turn on

1 it works
2 the bottom half works
3 it works
4 it works
5 it works

[nomoresonys]

Re: LG 42LA6130 did not turn on

Glad to hear it.

[neilc6]

Re: LG 42LA6130 did not turn on

Replace them all with new. They all have wear and will eventually fail. Lots of sellers on ebay and Aliexpress.

[magicpc]

Re: LG 42LA6130 did not turn on

Okay, but why the leds do not start on the old power supply? I tried such configurations:
Old power supply + old board - does not work
Old power supply + new board - does not work
New power supply + old board - does not work
New power supply + new board - works.

[yokoono]

Re: LG 42LA6130 did not turn on

Because the source knows a higher current. You have on the non-functional strips at least one LED with internal resistance. It needs a higher current to ignite. LED power supply uses a constant current source. The power supply with which the LEDs light up was built for a higher operating current. It was built for other strips.

[dskall]

Re: LG 42LA6130 did not turn on

You may have bad connections.
https://www.youtube.com/watch?v=3eTI...chaelDranfield

[nomoresonys]

Re: LG 42LA6130 did not turn on

is tv is circa about 2013, so prolly bad backlight in thar somewhars.