LG LED TV LS 57, screen goes black but audio continues

[leo_maash19]

Hi mahesh here, Im from India, my LG LED Tv of 42 Inch (LS 57 series) started to show some problem. when its On after some time the Video goes off, but audio continues on, the screen will be completely dead.
if i leave the tv off for few hours and ON it, The tv will continue to be normal for an hour, then later when the video goes off. if i restart the Tv video goes off with in minutes.
when the video is ON, the picture quality or backlight every thing semms to be good.

If i reduce the backlight from 100 to 30 (or less) the picture doesnt go off it extreme point, may be for 2 to 4 hours. and as i searched in web circuit board might be the issue.
The LG repair guy (who charged me 1,150 INR just for a visit) said the circuit board and the motherboard both has to be replaced for 11,750 INR , i felt something fishy and i turned it down coz i feel there is better solution.
can you please suggest me a solution ... thankyou

 

[Phil1989]

Hi Mahesh, based on how you tried to make it display video for 2 to 4 hours, I might have an idea. you said that only the display is off. I am assuming that you are not watching from any movie players(such as DVD players). LED screens requires backlight to display images. Most of the guys in this site know about the backlight issue of some ACER laptops which just happened to be just the same as your problem. With the laptop LED screens some call the backlight power supply as inverter(I'm not sure with inverter). I suggest you seek second opinion from other technicians there and try pointing your backlight problem only. If I'm right, you might be able to see faint dark images whenever your display goes out. just try to look harder and closer on the screen.