NEC DTE-25G5THS Service Manual page 50

* TV set stand-by mode operations
-On stand-by mode, I501 microcontroller pin 63 (power) is set to low.
- So, Q809 collector is set to high.
-Then, I810 controlled rectifier gate pin is set to high and I810 is conducting.
- So, current flows from pin 16 SMPS transformer to the ground via I804 optocoupler and Q810 and
Q811 transistors (which are conducting).
- In these conditions, I801 delivers pulses on light mode and T801 produces voltages with reduced
power.
- As I810 is conducting, current flows also from pin 16 SMPS transformer to I823 (3.3V regulator) for
I501 com, IR receiver and front mask buttons supply voltage (then, remote control or front mask
buttons can be activated to leave stand-by mode).
I810
CONTROLLED
RECTIFIER
HIGH
R820
C830
HIGH
Q807
I810 controlled rectifier switching circuit
6V DC
R829
R830
Q808
HIGH
LOW
Q809
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Service Manual CP-785A
POWER