Philips LC04 Training Manual

PHILIPS CONSUMER ELECTRONICS

LC04

TECHNICAL TRAINING MANUAL

MMARTIN 01/09/05

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Overall Video Signal flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

1fH Signal Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Comb Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

2fH Signal Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Pixel Plus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Sync Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Audio Input Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Audio Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Power On Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Front IR/LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Board Level Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Service Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Abbreviation list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

FIGURE 1 - BOARD LOCATIONS

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FIGURE 2 - CONNECTOR LOCATIONS

INTRODUCTION

The LC04 chassis is an LCD TV chassis designed for the 2004 model year. It is available in
a 17, 23, and 26 inch screen sizes. It has an NTSC TV and FM Radio tuning systems. The
set will display HD via the VGA or HDMI inputs. A Computer can be connected with VGA or
HDMI connector. The set can also tune FM Radio which can be operated alone or while the
set is in the PC mode.

In the following, some of the sets features are listed.

Picture

Wide screen aspect ratio
Pixel resolution 1280 x 768
Progressive Scan
3D Comb filter
Progressive Scan
PIP (Picture in Picture)

Sound

10 watts power output (5 watts per channel)
2 on board flat speakers
Virtual Dolby Surround

Picture modes

4:3
14:9 Zoom
Super wide
Widescreen
Full Screen

Inputs

AV1 Composite/YPbPr(1fh only)
AV2 Composite/SVHS
AV3 Side Connection (Composite/SVHS)
AV4 HDMI: Digital PC/HD
AV5 VGA/RGB/Analog HD YPbPr

Tuning

VHF/UHF/Cable tuning
Stereo FM Radio

The hookup instructions and Quick Use guide are located at the end of the training manual.

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Board Location (Figure 1)

There are eight different in the LC04. These modules are exchanged during field service.

The Power supply panel supplies power to both the LCD panel and the other boards in the
set. This panel is exchange only. No schematic is included in the service manual for this
panel.

The TV/Scaler board contains most of the Video and Audio processing. This board is
repairable to component level.

The Pixel Plus panel enhances the picture before feeding it to the LCD panel.

The Rear I/O panel has the 1Fh Composite, 1Fh Component, HD and PC RGB, Component,
and HDMI inputs.

The Side I/O panel has the Headphone, Composite, and SVHS connections.

The 3D Comb filter panel performs a digital separation of the Composite Video inputs.

Figure 2 shows the connector locations in the set.

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REAR VIEW -LC04

Overall Video signal flow (Figure 3)

There are two large scale IC’s in the LC04. The Hercules chip contains the control interface,
Video processing, and Audio processing. The Hercules also performs TV and FM Radio sig­nal processing. The 3D Comb filter circuit digitally separates and Y and C signal from the
Composite video. The Histogram circuit performs Luminance and Chroma enhancements for
the picture. All of the 1Fh video processing is performed in the Hercules.

The Scaler performs A/D, Digital picture enhancement, and rescaling. All of the 2Fh signal
processing is performed by the Scaler.

The Pixel Plus circuit enhances the picture from the Scaler before feeding it to the LCD
panel.

FIGURE 3 - OVERALL VIDEO SIGNAL FLOW

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FIGURE 4 - 1FH SIGNAL PROCESSING

1Fh Signal processing (Figure 4)

The Tuning System in the LC04 can tune both TV and FM Radio frequencies. The set does
not tune ATSC channels.

IF signals from the Tuner, 1302, is output on Pin 11 and fed to the SAW filter, 1328. The sig­nal is then fed to IC 7011, the Hercules chip, on Pins 24 and 25. The output of the
Demodulator is fed to an internal switch, SW1. SW1 selects between the output of the
Demodulator or Composite video from AV1 which is fed to the IC via Pin 48. The selected
signal is then fed to a Sound Trap and to SW2. SW2 selects between the output of the
Sound Trap, AV2, or AV3. If the selected signal on SW2 is Composite video, it is fed to the
3D Comb Filter panel. If the selected signal is Y, it is fed to SW3. SW3 selects the Y signal
from either SW2 or the 3D Comb Filter panel. SW4 selects C from the 3D Comb Filter or
selected C on Pin 59. The STATUS1 line on Pin 116 selects C from AV2 or AV3. If the STA­TUS1 line is high, Transistor 7226 is turned On, muting AV3. Transistor 7227 is turned Off,
allowing 7225 to pass the C from AV2. If the STATUS1 line is Low, Transistor 7226 is turned
Off, allowing the C from AV3 to pass. Transistor 7227 is turned On in this case, muting the C
from AV2. The Composite inputs on AV2 and AV3 are Mini Jack type connectors.

The output of SW3 is fed to the RGB/YPbPr Insert switch. The C signal is fed to a
Demodulator circuit which then feeds UV to the switch. The Insert Switch selects between
the internal YUV and external YPbPr signal. The YPbPr signal is converted to a YUV signal
in this section. The external YPbPr input can only accept 480i or 1Fh signals. The output of
the switch is fed to a YUV interface circuit. The YUV Interface circuit outputs the signal to
7560, Histogram processing IC. The signal is fed back to 7011 via Pins 70, 71, and 72.

The Signal is then fed to an output circuit. This circuit has fixed Contrast, Brightness, and
White Tone circuits. Closed Caption or Teletext is added to the video in this circuit. OSD is
inserted in the Scaler circuit. RGB drive is output on Pins 85, 86, and 87. This is a 1Fh ana­log drive signal. Horizontal Sync is output on Pin 67. Vertical Sync is output on Pin 23.
Sandcastle in/out is located on Pin 66.

The Hercules, 7011, also has the Main Microprocessor for the set. The SDA and SCL lines
on Pins 109 and 108 are used to communicate with the rest of the set. IC 7099, NVM, stores
the settings for the Hercules Microprocessor.

The Histogram circuit performs several functions. It improves the Luminance of the picture by
sampling the picture over five amplitude segments. This information is processed to improve
the overall contrast level of the picture. Picture sharpness is improved by sharpening the light
to dark changes in the picture. The Blue stretch circuit detects colors that are near white and
shifts the color more toward blue to give a brighter impression. Skin tone correction is
accomplished by changing the UV mix when colors in the skin tone range are detected.

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NTSC COMB FILTER CIRCUIT (Figure 5)

The Comb Filter circuit separates the Chrominance and Luminance, YC, from the composite
video. This is a separate PC board that plugs into the System board. The video signal is
amplified by Transistors 703. Transistors 7809, 7862, 7861, and 7860 separate
the Sync from the composite video. The Sync is fed to Pin 76 of 7023. If non-standard Sync
is detected, as with a video game, 7023 performs a 3-line sync separation. The composite
video is buffered by 7808 and fed to a 6MHz filter, 5806. This prevents any high frequency
signals from causing problems with the A/D conversion. The signal from 5806 is buffered by
Transistor 7812 and fed to Pin 88 of 7823. A Clamp circuit sets the sampling range of the
A/D converter. A full frame 3D YC separation is performed by the YCS circuit. The YC signal
is then output to two D/A converters that output C on Pin 83 and Y on Pin 84. The Y signal is
buffered by 7803 before being fed to a 6MHz filter to remove any high frequency components
generated by the D/A conversion. The signal is then buffered by Transistors 7802, 7801, and
7800 before being fed back to the SSB via the System board. A similar circuit also filters the
C signal.

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FIGURE 5 - 3D COMB FILTER CIRCUIT

FIGURE 6 - 2fH VIDEO PROCESSING

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2fh Video processing (Figure 6)

The 2Fh section accepts both HD and PC inputs in both analog or digital formats. This sec­tion also up-scales the video from the 1Fh section of the TV.

In the HD mode, the set will display:

1080i YPbPr
720p YPbPr
480p YPbPr

This can be input through the VGA or HDMI connectors.

In the PC mode, the set will display:

VGA 640x480 60,72,75,85Hz RGB
VGA 720x400 70,85Hz RGB
VGA 640x350 70,85Hz RGB
MAC 640x480 66.67Hz RGB
MAC 832x624 74.55Hz RGB
SVGA 800x600 56,60,72,75,85Hz RGB
XGA 1024x768 60,70,75,85Hz RGB
WXGA 1280x768 60,75Hz RGB

This can be input through the VGA or HDMI connectors. Inputs using the HDMI connector
must be in an HDMI or DVI digital format.

The DVI connector located on the Rear I/O panel is fed to IC 7808 located on the SSB. IC
7808, the HDMI receiver, detects the TMDS signal and outputs it to the Scaler on 3 8bit data
lines.

The signal on the VGA connector can be either RGB from a computer or YPbPr from an HD
source. If the signal is RGB, the signal is routed to the Scaler via IC 7606, This is controlled
by the PC_HD_SEL line from the Scaler. For PC signals with separate Horizontal and
Vertical sync, the Sync is fed to IC 7605 and then to the Scaler. IC 7605 selected between
the VGA connector and Sync from the Hercules. YPbPr signals from the VGA connector are
fed to IC7607. The input is selected by the Scaler via the SD_HD_SEL line from the Scaler.
This IC has triple Low Pass Filters which clamp the signal before feeding them to the Scaler.
The HD_FILTER line from the Scaler selects between NTSC, if the output of the Hercules is
selected or HD if the VGA connector is selected.

The selected signals are fed to triple A/D converters in the Scaler. The Scaler rescales the
picture as well as performing the Picture in Picture function. An SDRAM IC, 7501, stores the
frames as they are being processed by the Scaler.

The second microprocessor is located in the Scaler. The program for the Scaler is stored IC
7530, Flash Ram. The program can be update via connector 1304 using the ComPair tool.
The Hercules communicates with the Scaler via the SDA and SCL lines.

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FIGURE 7 - PIXEL PLUS CIRCUIT

Pixel Plus circuit (Figure 7)

The Pixel Plus circuit enhances the video from the Scaler IC. The LVDS output from the
Scaler is decoded by 7202. The signal is then fed to 7101, EPLD, for the Pixel Plus process­ing. The EPLD provides Color improvement and Sharpness enhancement for the picture.
The 24 bit output of the EPLD is fed to 7403, LVDS Transmitter. The output of 7403 is fed to
the LCD panel.

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