LG FLATRON L2323T, Service Manual

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DESCRIPTION OF BLOCK DIAGRAM
1. Input Selection Circuit
This block is composed of 74VHCT126A(U10)and
peripheral devices. There are two inputs, Analog and
Digital H/V Sync.
74VHCT126A(U10) chooses one input and outputs
selected input through sync selection pin (Pin1,4,13).
2. A/D Converter
This block is composed of AD9888 (U12) and
peripheral devices. AD9888(U12) includes A/D
converter, Pre-amp, and PLL.The basic RGB signal
(0.7Vp-p) is input to R,G,B pin of AD9888(U12).
Input video signal is amplified, Phase locked , A/D
converted to 8bits digital signal by this IC(U12) And
send the Digital video signal to MX88L285(U201).
U12 makes clock for MX88L285(U201)
3. TMDS Receiver
This Block is composed of SiI161B (U2) and
peripheral devices.
This ICs decodes TMDS Input signal from DVI-D Pin
(J1) and make 8bit digital signal to send Digital signal
to MX88L285(U201).
4. DDC controller
This block is composed of P89C662(U43) and
peripheral devices. P89C662(U43) controls peripheral
devices through IIC line.
Major functions are (1) to control Flash memory
through DDC-SCLA, DDC-SDAA of D-sub And (2) to
store EDID data in the EEPROM (U34,U49)
5. Video Decoder
This block is composed of VPC3230D(U601) and
peripheral devices.
P89C662(U43) controls this IC through IIC Line. This
IC analyzes input signal of CVBS, Y/C, Y/Pb/Pr and
output analyzed signal (8bit interlace signal) to De-
interlace block.
Analyzed signal has video control signals like
Contrast, Brightness, Sharpness, Color signals
Including Adaptive Comb Filter.
6. DTV Circuit
This block is composed of AD9883(U14) and
peripheral devices. AD9883(U14) includes A/D
converter, Pre-amp, and PLL.
Input video signal is amplified, Phase locked , A/D
converted to 8bits digital signal by this IC(U14) And
send the Digital video signal to MX88L285(U201).
U14 makes clock for MX88L285(U201)
7. Audio Decoder
This block is composed of MSP3410G (U3) and
peripheral devices. P89C662(U43) controls this IC
through IIC Line.
This IC analyzes Audio input signal through A/V Jack
and PC audio, DVD/ DTV(SCART Jack) audio.
8. De-interlacer
This block is composed of FLI2310(U302) and
peripheral devices.
P89C662(U43) controls this IC through IIC Line. And
this IC convert 8 Bit Interlace Y/UV signal to
Deinterlace signal.
It output converted signal to Format Converter
MX88L285(U201).
9. Format Converter
This block is composed of MX88L285(U201),
MX29LV004B(U28), EM638325(U26,U27) and
peripheral devices. P89C662 controls this IC through
parallel line.
MX88L285(U201) processes outputs of A/D
Converter and TMDS Receiver, DTV circuit, De-
interlace output and output processed 48 Bit Digital
signal to LVDS Transmitter THC63LVDM83(U801).
MX88L285(U201) is Format Converter IC that receive
Digital signal and output proper frame signal to LCD
Module(1280X768).
10. Panel-Link Circuit
LVDS Transmitter THC63LVDM83(U801) is the IC
that receives output digital signal of MX88L285(U201)
and output to LCD Module.
The signal format is Panel-link. LCD Module has
Panel-link receiver that is same output of
MX88L285(U201).
This is the best for reduction EMI problem and the
number of pin connector.
11. DC/DC Converter block
DC/DC Converters convert the input 24V to proper
2.5V, 3.3V, 5V, 8V for main board. For shooting heat
trouble, we use the DC/DC converting IC.
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