Panasonic TH-65PX600U Service Manual page 22

STB5V Distribution
The STB5V is routed through the D board to be connected to the DG board. In the DG
board, the STB5V is used to generate the 1.5V and the 3.3V to power the CPU (IC1103).
The STB5V is also routed through the H board and applied to the PA SOS detect circuit.
The explanation for the circuit that generates the STB3.3V and STB1.5V is covered in the
next slide.
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