LG 42LV5500 Training Presentation page 78

FRONT (IR, INTELLIGENT SENSOR and POWER LED) SECTION
The Intelligent Sensor and IR board (located on the bottom left as viewed from the rear) contains the IR
(Infrared Remote Sensor) and the Intelligent Sensor. This board also has the Soft Touch Key Board.
The IR board receives it operating B+ pin 6 from the Main P901 (STBY 3.5V).
The IR (Infrared) remote receiver can be measured (1.48V) at pin 9 of connector P901 on the Main board in
Stand-By. During run pin 9 reads (1.45V).
The IR pulses (2V p/p) are sent to the Main board and on to the Microprocessor (IC602) via pin 16. The IR pulses (2V p/p) are sent to the Main board and on to the Microprocessor (IC602) via pin 16.
The Front Power LEDs are controlled by different Clock and Data lines which communicate with the LED
Driver IC U1 on the IR board. These clock and data lines are from the Main board P901 pins 14 and 15 which
are only active when the Power is turned on or off.
The Key board is routed from the IR board Key 1 (pin 4) and Key 2 (pin 5). Arriving at P901 on the Main
Board, then to the Microprocessor 25 and 26 lines.
The Intelligent Sensor communicates with the Micro Processor IC602 pins 3 & 4 via clock and data lines
EEPROM SCL and EEPROM SDA arriving on connector P901 pins 1 and 2 on the Main board EEPROM_SCL and EEPROM_SDA arriving on connector P901 pins 1 and 2 on the Main board.
The Intelligent Sensor circuit receives it's operational voltage when the set turns on via pin 11
(3.3V_Normal).
1
Front IR and Soft
Touch Key Board
p/n EBR72671001
To Main Board
May 201 1 LCD TV 42LV5500
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