Daewoo DDT-21H9ZZF, Service Manual, Page: 50 / 83

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Service Manual CP-099F
I802
STAND BY
CONTROLLER
I502
EEP ROM
Photo
coupler
D801~D804
(BRIDGE)
D806~D809
(BRIDGE)
I801
SMPS IC
Q516
Q517
SW01
POWER SW
I503
3.3 V
I504
Reset
POWER
Reset
I808
5 V
4
5
4
5
2
I501
VCT 383X
5
3
L501
L502
5 V
SCL SDA
15 54 25
59 60
6
8
T802
STAND BY
TRANS FORMER
5
45
58
1
11
I801
SMPS
TRANS FORMER
3
4
3
10
5 V 3.3 V
5 V
3.3 V
5-10 TV start-up, TV normal run and stand by mode operations
5-10-1 TV start-up operations
* Schematic diagram for start-up operations
* TV start-up and microcontroller initialization.
- When AC POWER is on, rectified voltage is applied to transformer. T802. That voltage is rectified by
D801, D802, D803, and D804. T802. transformer is controlled by I802 and makes DC 5V at pin 11.
- When POWER SWITCH(SW01) is pushed on, voltage (5V / 3.3V) are supplied at I501 (pin3, 15 /
25,54).
- Reset voltage is applied at RESET pin(58) of I501.
- Microcontroller(I501) starts a initial operation, POWER(pin5) is high. Then the secondary voltages of
the T801 are applied.
- The microcontroller consults I502 EEPROM via IIC bus to know the last TV set mode (normal run
mode or stand-by mode) before switchins off.