The Complete Handbook of Television Circuit Boards

Chapter 1: Understanding Television Circuit Boards

When you open the back cover of a modern flat-screen television, you are not looking at a single monolithic piece of technology. You are looking at a system of specialized printed circuit boards, each with a sharply defined job. Unlike a personal computer, where one motherboard might handle the vast majority of processing, a television spreads its work across multiple boards because of the high voltages, the massive data rates of video signals, and the need to keep certain circuitry physically close to the display panel itself. Understanding this division of labor is the first step to being able to repair, replace, or even simply evaluate a television circuit board with confidence.

As a professional or a serious hobbyist, your work will almost always involve one of four primary board categories. The power supply board takes the raw alternating current from your wall outlet and converts it into the various direct current rails the rest of the system needs. The main board, often called the system-on-chip board or the signal board, is the brain that receives input from your source devices, processes the video and audio, and manages the overall operating system in a smart television. The T-con board, or timing controller board, sits between the main board and the LCD panel itself. Finally, the LED driver board controls the backlight, which in a modern television is almost always an array of light emitting diodes. While fixed panels and integrated designs are