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TC-L37DT30 Standby Power (3)
When the TV is plugged in:
AC is applied to the standby circuit in the power supply to produce STB5V.
The STB5V is provided to the A board via pin 2 of connector P2.
The STB5V from pin 2 of connector P2 is applied to the Analog ASIC (IC5000) to power the
Main CPU/PEAKS LDA3 (IC8000) on the A board. The Analog ASIC (IC5000) converts the
STB5V to STB3.3V and STB1.2V. These two voltages energize and prepare the
microprocessor (CPU) for program execution.
The STB3.3V from the Analog ASIC (IC5000), besides being applied to the CPU, is also applied to the remote
control receiver and the power LED on the K board through connector A1/K1 (pin 3).
When the CPU receives 3.3V and 1.2V, it outputs the SUB-ON command that is provided to
the P board. This command triggers the switches on the P board and only lasts approximately
15 seconds. The function of this command is to turn on the circuit that generates the “F15V” on
the P board.
The +16V from the P board is applied to the A board through connector P2 (pins 4 through 6).
This voltage is applied to several voltage regulators to generates the SUB voltages used by
the A board for a self-check operation.
If the STB5V is missing, the TV is dead (No power)
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