LG televisions are manufactured in a variety of styles: Models use liquid crystal display, light-emitting diode or plasma screen technology. Problems with internal components found within an LG television set can cause the image to display on only half the screen as well as other issues, such as lines across the screen or colored dots.
Electromagnetic signal interference from home appliances is a common cause of screen display problems on LG televisions. Symptoms of electronic interference from other appliances include horizontal or vertical bars covering large portions of the screen or a shaky picture. Any large appliances, such as a microwave, vacuum or power tools, should be moved away from the LG TV to prevent against possible electronic interference.
LG plasma screens can become defective and also cause faulty display problems. Plasma is used in television screens to display a picture because it can be easily manipulated and controlled to create a color image. Broken or cracked plasma screens can't be used, and can cost more than the price of an entire television set. Other than a half-screen display, symptoms of a bad plasma screen can include colored vertical lines, distorted colors in the corners or flashing red dots.
Sustain and Buffer Boards
LG television sets use a number of control boards, such as buffer or sustain boards, that control the quality and brightness of the picture being shown. X-sustain and Y-sustain boards, found only in plasma televisions, are similar in size to a plasma TV's power supply board, typically the largest board found among the television's electronic components. Buffer boards are long, thin boards typically connected to the Y-sustain board inside a plasma TV. For LCD TVs, inverter boards or backlight inverters, control the light levels behind the picture. Malfunctions in any of these boards can cause the backlight to go out on part of the screen, reducing the amount of the picture that a TV actually shows. Other symptoms of bad sustain or buffer boards include vertical lines or horizontal lines that are two to three inches wide spanning the screen.
Other LG Picture Problems
LG televisions that use an antenna may have lines or streaks appear in the picture displayed on the TV screen. Check and adjust the antenna to improve the LG TV's picture clarity. Poor picture quality on any LG television set may be due to close proximity between the television and VCR or improperly installed video cables. If the entire display is too dark, adjust the color or brightness settings on your LG TV. Display problems that occur when a high-definition multimedia interface, or HDMI, cable is connected may be caused by an incompatible cable; LG televisions require HDMI cable rated at version 1.3 or higher.