Panasonic TH-65PX600U Service Manual page 25

The F-STB-ON voltage (3.2) from pin 13 of connector P25 is applied to pin 23 of the Power
CPU (IC501) on the P board.
IC501 sends out commands to first turn on the primary circuit of the power supply, and then
the circuit that allows the FSTB14V to develop on the secondary circuit.
1. The relay commands (high) from pins 11 and 12 of IC501 are used to trigger the relays
RL402 and RL403. The incoming AC passes through the relays and enters the bridge
rectifier D401. The DC voltage from D401 is applied to the Power Factor Control (PFC)
circuit (T401 and IC406). The PFC outputs 395VDC is applied to the switching circuit
(Q408, Q409, Q412, and Q413). The operation of this switching circuit is controlled by
the transformer T402 which is driven by the power control IC, IC520.
2. A low from pin 10 and a high from pin 15 of IC501 are used to turn on the power
control IC (IC520) to energize the primary of transformer T402 and allow the switching
circuit to drive transformer T404 (not shown in the diagram.
3. The secondary circuit of transformer T404 outputs the VSUS, VDA, and 15V voltage
sources.
F-STB-ON (Primary)
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