Panasonic TC-L42D2 Technical Manual page 26

Power-on Part 1_ All Except D2
When the power button of the TV or remote control is pressed, The MPU (IC8001) of the A
board outputs the TV_SUB_ON command to turn on the transistors Q4770 and Q4771 which
provide STB5V to the power relay. The STB5V enters the power supply board via pin 11 of
connector P2. The TV_SUB_ON command is also provided to the power supply to activate a
circuit that provides a ground connection to the relay. When the relay is closed, the switched
mode supply goes in operation to create the Sound15V, and DTV12V. The DTV12V is regulated
to other voltages to power the A-Board.
Caution: All boards in the unit are to be exchanged only.
Slide # 26