LG WM3987HW does not start (no power)

SOURCE: I have a LG plasma TV. The picture won't come on but the sound does. It's a 52" model# 50pc50-ul. Production code 50pc50-ul AusYLSJR. Power 100-240v~50/60 Hz 4.5. Pcc ID: BEH50Pc5DUL.

This TV is 2007-2008 vintage. If you've had it this long without losing the picture, you've been lucky. Plasma and LCD panels are excited electrically to generate images, but they do not produce adequate light on their own to make the image visible. Thus, manufacturers install a backlight circuit which treats the LCD/Plasma panel much like a slide in a slide projector. When this backlight fails, you lose the visible image, even though the image is still on the panel. Older sets such as yours used florescent bulbs to light the screen. The use high-voltage inverters (ballast) that are the usual failure culprits. Newer sets use LED lighting. These use far less current and tend to last longer, but the jury is still out on their longevity as they are fairly new to the market. Inverters can be replaced, but be advised, as the florescent bulb ages, its color will change and it will affect image quality. So you may want to consider upgrading to a newer set.