My lg tv picture wont come on

SOURCE: LG 42LG5 TURN ON TV PICTURE GOES BLACK

This could be 1 of a few things here. Without opening up your set and trying to look at voltages or indiciator lights I couldn't tell you exactly without some more info.

Without looking at it myself here are my thoughts and where I would first look at.

It may be a main board because:
1) Main board processes all your audio/video signals. Bad main board means bad video processing. Could do that. Especially if the main board is not sending the right signal or a bad signal to the rest of the boards so they don't do their jobs. 

It may be a power supply because:
1) Power supply is well, the power supply. If it's sending inadaquete voltage to the main board you may not be recieving enough juice to keep that main board doing your video processing or further up the line keeping enough juice flowing to your TCon board to keep it telling things where to go and what to do. The power supply sends voltages to your Ballast board(controls your lights) and to your main board through which power is supplied to your TCon board via a LVDS line and a +12/+16V signals. If the power supply isn't pumping out enough juice to keep the TCon or Main Board running, it could be a problem. By the same token it could be that your P/S isn't sending power out to your ballast board. 

It could be a TCon because:
1) If the TCon is bad, you won't get your pictures. This could be the TCon board itself or the LVDS cable from your TCon to your Main. However, with few exceptions, if it's a bad TCon you're looking at a total panel replacement. 

It could be a ballast board because:
1) The Ballast Board controls the lighting behind the LCD screen. If this isn't working right you won't be seeing much of anything without that back lighting. If this is bad, it's a panel replacement. These are not field replaceable items by LG. 

Based on the symptoms, without more data or a eyes-on view of it, I would say you're most likely looking at a Main Brd or PSU problem. 

SOURCE: Low volume on LG HDTV

I encountered the same thing using the HDMI interface on my new TWC cable box (Motorola DCX-3200). After a little bit of research, I finally fixed it by changing the digital audio mode in the cable box using this procedure:

1. Be sure the TV is on and connected to the cable box.
2. Using the cable box remote turn power OFF.
3. Immediately press the MENU key on the remote. The USER SETTINGS menu should appear on the TV screen.
4. Select the ADDITIONAL HDMI SETTINGS >>> menu item.
5. The ADDITIONAL HDMI SETTINGS menu will appear.
6. Scroll to the AUDIO OUTPUT item and select this.
7. Change the setting from AUTO to L-PCM.
8. Return to the main page
9. Using the remote, cycle power OFF.
10. When the cable box is turned on again, you should be good to go.

I realize these instructions are specific to the DCX-3200, but there may be a similar setup option available in your cable box as well.

The problem here is that the cable box is by default configured to use Dolby Digital audio, which requires an additional 10dB of headroom to deal with the boosted LFE channel. If the cable operator hasn't taken pains to set the system up correctly (and most haven't, apparently), the digital audio level sent on the HDMI interface will be approximately 11dB down from normal analog line levels on the HDTV channels. Changing to straight linear PCM sets the TV receiver audio level on the HDTV channels to match the levels on the non-HD channels.

The only problem with this fix is that if you intend to feed a Home Theater receiver that uses Dolby Digital processing with the cable box output you will lose the Dolby encoding feature and be forced into straight 2-channel stereo. For a simple installation like mine where I'm just feeding the TV, this fix works fine. If you have a more complex setup that takes advantage of Dolby Digital features (when it's available in program material), you may have to live with the problem.

For a technical reference on why this happens, see http://www.megahz.com/specimages/Dolby/LM100%20Cable%20App%20Note%2011-05.pdf

Hope this is useful.

SOURCE: lg lcd tv keeps changing chanels

Come on, lets try to solve this. Take the batteries out of the remote so it can't interfere and try changing the channels and volume with the buttons on the tv. If this works then someone has spillled something onto the remote and gummed it all out. You simply need to take the remote apart and clean it out. If the buttons on the tv do th same as the remote did then yes, take it back.

SOURCE: LG 47LC7DF Green Light Blinks 16 Times - No Picture or Sound

The lights indicate what the issue is. Kind of like your check engine light in your car tells you something is wrong with the engine.

SOURCE: My LG Plasma 42PC3D turns on and off repeatedly. I

Your plasma TV has a power supply 6709900019A. These power supplies failed due to defective capacitors. See the picture below and check the capacitors mark with the red lines. There are 10 capacitors that should be replaced even if they do not show signs of bulging/swelling on top.
The value of the capacitors is 3300uF/10V but you can use 25 volts as long as they fit in the space provided by design.