Wiring inside a TV receiver, c 1970s.
© National Media Museum / Science & Society Picture Library
Rear view of set showing wiring. By the 1970s the valves in televisions had been replaced by transistors. The resulting chasis is dominated by the tube that displays the picture and the components that supply the high voltages it needs. The transistors themselves are almost invisible. By the 1980s most transistors had become even smaller, disappearing inside integrated circuits.