After switch on the tv the black background changes to red tinted color and picture look odd. this changes after 1 hour from start. pl inform any soluctin

Please change the T-CON board, if it did not fix the problem, you may have a defective LCD Panel.

Hi:
You may have a problem with the inverters in the unit, they are responsible for lighting up the back panel. Check or have checked the power supply voltage to the inverters, should be around 18-24 volts DC. Also leaky capacitors on the power supply will cause this issue as well as leaky or puffy capacitors on the inverter.

i think is the blue mirror in side the tv...it has 4 mirrors inside

I want you to do a simple visual check of something that will tell me what the problem may be.

Go to a channel that is in black and white--old movie and tell me what color the screen/picture is.

You can also turn the COLOR in the customer menu all the way off and look that way.

What we are trying to see here is if TRACKING is set correctly or has changed. If the screen is somewhat to medium reddish it may be an adjustment outside of the customer menu.

Let me know what you find--I have seen several of these where the black and white picture was somewhat red--the idea is it should be as close to black and white as possible--if red is the predominant background color the picture will look reddish.

If this has helped and you confirm the red instead of black and white picture--I can tell you a easy way to adjust this.

If this information told you something you did not know and helps you rate this solution as I do this here for free.

SD TECH

Picture Menu
Picture Mode: Expert1
*Backlight: 16
*Contrast: 83
*Brightness: 53
Sharpness: 50
*Color: 55
*Tint: 0
Expert Control

• Fresh Contrast: Off
• Noise Reduction: Medium
• Gamma: Medium
• Black Level: Low
• Real Cinema: On
• TruMotion: Low
• Color Standard: HD (N/A w/HDMI)
• White Balance: Warm
• **Method: 10-Point IRE
  • 10 IRE
    • **Red: 1
    • **Green: 2
    • **Blue: -16
  • 20 IRE
    • **Red: -6
    • **Green: 0
    • **Blue: -7
  • 30 IRE
    • **Red: -5
    • **Green: 0
    • **Blue: -4
  • 40 IRE
    • **Red: -8
    • **Green: 0
    • **Blue: -4
  • 50 IRE
    • **Red: -4
    • **Green: 4
    • **Blue: -4
  • 60 IRE
    • **Red: -6
    • **Green: 6
    • **Blue: -5
  • 70 IRE
    • **Red: -8
    • **Green: 3
    • **Blue: -10
  • 80 IRE
    • **Red: -8
    • **Green: 7
    • **Blue: -16
  • 90 IRE
    • **Red: -9
    • **Green: 5
    • **Blue: -18
  • 100 IRE
    • **Red: -10
    • **Green: 4
    • **Blue: -9

Color Management System

• Red Color: 0
• Red Tint: 0
• Green Color: 0
• Green Tint: -15
• Blue Color: 0
• Blue Tint: 11
• Yellow Color: 15
• Yellow Tint: 2
• Cyan Color: -15
• Cyan Tint: 0
• Magenta Color: 0
• Magenta Tint: -1

lg70 nice tv excellent processor just to bad there is no intensity control on color management oh well still better than what the three s are pushing block out the hype lg will be number 1 in a few years haters are starting to come around and well leds coming,

p.s. i dont work for lg just tired of losers bashing stuff because they dont own it.
im isf certified those settings are right on the money straighter than a ruler

Colorimetre HCFR software
AVC HD 709 calibration disk
Spyder2 colorimeter (I know most prefer the Eye-One meters, but the Spyder2 was available from my job at no cost)

Here are the settings:

PS3 Blu-Ray player

Output Format (HDMI): Y Pb/Cb Pr/Cr (important!!! NOT RGB output)
BD 1080p 24hz Output (HDMI): On (this TV can reproduce video at 48hz for accurate 2:2 pulldown)
Y Pb/Cb Pr/Cr Super White (HDMI): On (not sure if this matters)

42LG50 Settings

Aspect Ratio: Set By Program (Personal Preference)
Picture Mode: Expert 1
Backlight: 50 (Personal Preference)
Contrast: 54
Brightness: 54
Sharpness: 40 (Personal Preference)
Color: 50
Tint: 0

Fresh Contrast: Off
Noise Reduction: Off
Gamma: Medium
Black Level: Low
Real Cinema: On

White Balance: Warm
Method: 10 Point IRE

10 (-3,8,-16)
20 (15,24,-21)
30 (20,36,-22)
40 (3,19,-40)
50 (8,34,-41)
60 (10,50,-20)
70 (-5,50,-8)
80 (-16,50,18
90 (-14,50,30)
100 (-22,38,21)

Red Color: -3
Red Tint: 0
Green Color: 10
Green Tint: 0
Blue Color: 14
Blue Tint: 0
Yellow Color: 0
Yellow Tint: 1
Cyan Color: -11
Cyan Tint: 0
Magenta Color: 0
Magenta Tint: -2

Take time to get used to the settings, you may think the screen looks dull at first. The truth is most people have way too much contrast on their TVs.
These settings will also work for Cable or Dish hookups, in which case you may change the Noise Reduction option to Medium to reduce signal noise.

OR....

2POINT IRE

Backlight: 65
Contrast: 55
Brightness: 45
Sharpness: 50
Color: 45
Tint: 0

Fresh Contrast: Off
Noise Reduction: Off
Gamma: Medium
Black Level: Low
Real Cinema: On

White Balance: Warm
Method: 2 Point

Red Color: 3
Red Tint: 0
Green Color: 9
Green Tint: 2
Blue Color: -1
Blue Tint: 0
Yellow Color: 6
Yellow Tint: 5
Cyan Color: -1
Cyan Tint: 1
Magenta Color: 2
Magenta Tint: -1

Good day.
Your unit is still worth. It may be a caused of loose contacts along the circuitry. It can be remedied by resoldering the terminals particularly the chroma section and the crt circuit.


chris

Problem solved. I tried playing DVD and the TV picture was fine. So I double-checked cable wires from cable box - one of the wires was loose (obviously it was the red color input). After tightening, the TV picture is good as new.

Did you ever find out what it was?

If, when you turn down the color control all the way you have a black and red picture, then your picture tube is most likely weak and it's time to replace the set. If the black and white picture is normal, then the set could have a problem in the chroma circuit. Either way, it would not likely be worth repairing.