Lg 47lw4500

[Jimmy1979]

Hello
I got this led tv with following problem.
I turns on lg logo for 2 seconds then backlight goes out.
If i put a flash light on the panel there is a image.
Does someone know if the problem is on the power supply or the mainboard?

[dskall]

Re: Lg 47lw4500

Bad led's

[Jimmy1979]

Re: Lg 47lw4500

Bad led's

I opened the tv to watch if all leds are on for the 2 seconds.
All leds turning on no bad leds

[dskall]

Re: Lg 47lw4500

Need good clear straight on pictures of back of tv with cover off and each board. and picture of connector on power supply board.

[Jimmy1979]

Re: Lg 47lw4500

Need good clear straight on pictures of back of tv with cover off and each board. and picture of connector on power supply board.

I will post tommorrow tv is at my parents house.

[Jimmy1979]

Re: Lg 47lw4500

Need good clear straight on pictures of back of tv with cover off and each board. and picture of connector on power supply board.

Can i place jumpers to see if backlight working normal?

Here is the connector from service manual

[Jimmy1979]

Re: Lg 47lw4500

Need good clear straight on pictures of back of tv with cover off and each board. and picture of connector on power supply board.

Here are pictures

[Jimmy1979]

Re: Lg 47lw4500

Here are pictures

Pwr-on 3,3v. 24v = 23,8
24v= 23,8v. 24v =23,8
Gnd Gnd
Gnd. Gnd
3,5v = 3,4. 3,5v = 3,4
3,5v = 3,4. 3,5v = 3,4
Gnd. Gnd
Gnd. Vsync = 0
12v = 11,7. Drv-on = 3,1
12v = 11,7. Nc = 0
12v = 11,7. Pwm = 1,0
Nc = 0. Error = 3,4v

[dick_barton]

Re: Lg 47lw4500

Can you provide the voltages at the led connector

[Jimmy1979]

Re: Lg 47lw4500

Can you provide the voltages at the led connector

35,6v this is to low
Sometimes tv works and then voltage is 60v
I can see darker leds then others in picture
Does this means leds no good?
All leds burning but some lower in brightness

[dskall]

Re: Lg 47lw4500

Just like post #2. The fact that it is an LG makes it about 90% chance of bad leds. Just been my experience.

[dick_barton]

Re: Lg 47lw4500

35,6v this is to low
Sometimes tv works and then voltage is 60v
I can see darker leds then others in picture
Does this means leds no good?
All leds burning but some lower in brightness

60V is the correct working voltage for the leds. You have just confirmed that you have faulty leds (darker leds)

[Jimmy1979]

Re: Lg 47lw4500

60V is the correct working voltage for the leds. You have just confirmed that you have faulty leds (darker leds)

I will order a set left+ right and see what happends.

[Jimmy1979]

Re: Lg 47lw4500

I ordered and installed new led strips and problem is fixed.
Many thanx for the people who helped me.✌��

[dick_barton]

Re: Lg 47lw4500

Glad you got the set up and running again. Turn the backlights down to maximise the lifetime of the leds.

[Jimmy1979]

Re: Lg 47lw4500

Glad you got the set up and running again. Turn the backlights down to maximise the lifetime of the leds.

Thanx for your advice.
I did this already👍🏻