Main board

The main board is the computer inside the TV. It receives the picture from an antenna, an HDMI cable or the internet, decodes it, adds menus and apps, and sends a finished stream of frames on toward the screen.

It starts as a bare printed circuit board. A machine prints solder paste through a thin stencil onto every pad, then pick-and-place robots set down hundreds of parts in seconds:

• the system-on-chip, the brain, with DRAM as working memory and flash storage for the software and apps
• other integrated circuits for power management, sound, the TV tuner and HDMI
• a Wi-Fi and Bluetooth module and a crystal to keep time
• swarms of ceramic capacitors, resistors and inductors that steady and set the power
• connectors for HDMI, USB, network and antenna

The loaded board passes through a reflow oven, where the paste melts and joins every part at once. A heat sink goes on the main chip, and the board is tested and loaded with its software.

In the television, it takes power from the supply board and sends video to the timing controller board.