LG 50PK950 Training Manual page 132

MAIN BOARD SECTION
MAIN BOARD SECTION
The following section gives detailed information about the Main board. This board contains the
Microprocessor, Audio section, video section and all input, outputs. It also receives all input
signals and processes them to be delivered to the Control board via the LVDS cable.
The (VSB, 8VSB and QAM) tuner is located on the main board. This board is also where the
television's software upgrades are accomplished through the USB input.
The Main board also has a LAN (CAT5) input to allow open Internet access. In addition, the Main
board has an output to the Wireless Media box (Dongle) for control and either one of the USB ports
can accept the Dongle wireless receiver.
This board has no mechanical adjustments.
The Main Board Receives its operational voltage from the SMPS:
DURING STAND-BY: From SMPS
• STBY 5V
DURING RUN From SMPS : (STBY 5V remains):
• +5V for Video processing
• 17V for Audio and Tuner B+ (Stepped down to 5V)
• Distributes Key 1 and Key 2 to the Front IR Board then to the Front Key Pad.
• Receives Intelligent Sensor data from the Front IR Board (via SCL/SDA).
• Drives front Power LEDs.
• Distributes +3.3V_ST to the Front IR Board.
132 October 2010 50PK950 Plasma