Panasonic TH-65PX600U Service Manual page 35

PA board Circuit Explanation
The "F-STB-14V" at connector PA10 is supplied to the voltage input pins of both regulators
IC5601 and IC5602.
IC5601 is a dual voltage regulator. It generates 9V and 5V.
The SUB9V is output at pin 14 of IC5601 as soon as the STB14V is applied to pin 10. The
ON/OFF pin (pin 16) is permanently grounded. The SUB9V is used to turn on Q5613 to
provide a low to the second ON/OFF pin (pin 2), thus allowing the SUB5V to be output
from pin 4.
When the power is turned on, the "TUNER MAIN ON" line from pin 32 of connector PA20,
goes high (3.2V). This high is applied to Q5602 to turn it on. Q5602 outputs a low to turn on
Q5601. When Q5601 is on, it outputs the "MAIN 9V" to pin 5 of connector PA40.
The "TUNER MAIN ON" voltage is also applied to the base of Q5605 to turn it on. Q5601
outputs a low to turn on Q5603. When Q5603 is on, it outputs the "MAIN 5V" to pins 12
and 13 of connector PA20.
Q5610 also turns on when the "TUNER MAIN ON" voltage is applied to it, outputting a
low. This low is applied to both "ON/OFF" pins (15 and 1) of IC5602 allowing the "MAIN
3.3V" and the "MAIN 1.8V" to output at pins 13 and 3 respectively.
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