Service and Quality
Service Publications Dept.
One Philips Drive
P.O. Box 14810
Knoxville, TN 37914
Pg. SCHEMATIC DIAGRAMS AND PC BOARDS
1. PCB Locations
2. Power Supply (Diagram A1)
3. Line Deflection (Diagram A2)
4. Frame Deflection (Diagram A3)
5. Tuner IF (Diagram A4)
6. Video IF And Sound IF (Diagram A5)
7. Synchronization (Diagram A6)
8. Control (Diagram A7)
9. Audio Amplifier (Diagram A8)
10. BTSC (Stereo/SAP) Decoder (Diagram A9)
11. Audio/Video Source Switching (Diagram A10)
12. BTSC - NDBX Stereo Decoder (Diagram A11)
13. Front I/O + Control, Headphone (Diagram A12)
14. Rear I/O Cinch (Diagram A13)
15. PIP Interface (Diagram A16)
16. CRT Panel (Diagram B1)
Manual 7629
Model no.: 27PS60S321
First Publish: 12740 T8
Rev. Date: 2002-06-06
Print Date: 7/8/2004
17. Side AV and Headphone Panel (Diagram C)
18. PIP Panel (Diagram P)
19. Main Panel (component side)
20. Main Panel (copper side)
21. CRT Panel (component side)
22. CRT Panel (copper side)
23. Headphone Panel (component side)
24. Side AV Panel (component side)
25. PIP panel (component side)
26. PIP panel (copper side)
27. Top Control Panel (component side)
28. EPS Panel PCB (Top View only)
29. Card Interface Panel PCB (Top View)
30. Card Interface Panel PCB (Bottom View)
REFER TO SAFETY GUIDELINES
SAFETY NOTICE:
ANY PERSON ATTEMPTING TO SERVICE THIS CHASSIS MUST FAMILIARIZE
HIMSELF WITH THE CHASSIS AND BE AWARE OF THE NECESSARY SAFETY PRECAUTIONS
TO BE USED WHEN SERVICING ELECTRONIC EQUIPMENT CONTAINING HIGH VOLTAGES.
CAUTION: USE A SEPARATE ISOLATION TRANSFORMER FOR THIS UNIT WHEN SERVICING
Service and Quality
Service Publications Dept.
One Philips Drive
P.O. Box 14810
Knoxville, TN 37914
Manual 7629
Model no.: 27PS60S321
First Publish: 12740 T8
Rev. Date: 2002-06-06
Print Date: 7/8/2004
Mechanical Diagrams
REFER TO SAFETY GUIDELINES
SAFETY NOTICE:
HIMSELF WITH THE CHASSIS AND BE AWARE OF THE NECESSARY SAFETY PRECAUTIONS
TO BE USED WHEN SERVICING ELECTRONIC EQUIPMENT CONTAINING HIGH VOLTAGES.
CAUTION: USE A SEPARATE ISOLATION TRANSFORMER FOR THIS UNIT WHEN SERVICING
ANY PERSON ATTEMPTING TO SERVICE THIS CHASSIS MUST FAMILIARIZE
MAIN CABINET EXPLODED VIEWPage: 1 of 1
Philips Consumer Electronics
Technical Service Data
Service and Quality
Service Publications Dept.
One Philips Drive
P.O. Box 14810
Knoxville, TN 37914
Manual 7629
Model no.: 27PS60S321
First Publish: 12740 T8
Rev. Date: 2002-06-06
Print Date: 7/8/2004
Electrical Adjustments
REFER TO SAFETY GUIDELINES
SAFETY NOTICE:
HIMSELF WITH THE CHASSIS AND BE AWARE OF THE NECESSARY SAFETY PRECAUTIONS
TO BE USED WHEN SERVICING ELECTRONIC EQUIPMENT CONTAINING HIGH VOLTAGES.
CAUTION: USE A SEPARATE ISOLATION TRANSFORMER FOR THIS UNIT WHEN SERVICING
ANY PERSON ATTEMPTING TO SERVICE THIS CHASSIS MUST FAMILIARIZE
Alignments
Index of this chapter:
1. General Alignment Conditions
2. Commercial Mode ls SDAM Entry
3. Hardware Alignments
4. Software Alignments and Settings
Note: The Service Default Alignment Mode (SDAM) is described in the "Service
Modes, Error Codes and Fault Finding" section. SDAM menu navigation is performed
by using the MENU UP, MENU DOWN, MENU LEFT, and MENU RIGHT keys of the
remote control transmitter.
General Alignment Conditions
Perform all electrical adjustments under the following conditions:
AC voltage and frequency: 110 V (± 10 %), 60 Hz (± 5 %).
Connect the television set to the AC power via an isolation transformer.
Allow the televisi on set to warm up for approximately20 minutes.
Measure the voltages and waveforms in relation to chassi s ground (with the
exception of the voltages on the primary side of the power supply). Never use
heatsinks as ground.
Test probe: Ri > 10 MO; Ci < 2.5pF.
Use an isolated trimmer/screwdriver to perform the alignments.
Service Default Alignment Mode (SDAM) Entry for
Commercial Models
Note: For comm erci al models, a master setup remote control is required in order to access the Service
Default Alignment Mode (S DAM ) .
1. Use the master setup remote control to identify the television’s operational mode (either
“consumer” or “commercial”). Place the master setup r emote control in setup mode by
pressing the TV SETUP key.
2. Pr ess the RECALL key. Information similar to t he following will be displayed.
Status Item Status Data Meaning
SYSTEM STAT US
(L011TV-US4PV) Information title
MODE COMMERCIAL/CONSUMER Operational mode
CHANNEL CHANNEL, INPUT Currently tuned channel /i nput
DCM OFF/ON Data Comm. Module online/offli ne
CODES 209 222 1 33 Internal data for factory/service use
SIGNAL TUNED/NOT TUNED Valid signal present/absent
OP HRS 0031h Number of hours set has operated (hex)
ERRORS 0 0 0 0 0 Internal data for factory/service use
VERSION 3.3 Microproce sso r sof t ware ve rsi o n
N
3. To change the television’s mode, ensure the master setup remote contr ol is in setup mode,
then press the 0-2-4-9-9-5-MENU keys in order, without permitting the display to time out
while entering the key sequence.
ote: If the operational mode is changed, the television must be turned off and then back on to
complete the mode change. When the television is in consumer mode, do not use the master setup
remote control to activate commercial mode features.
4. W hen the t el evision is in commercial mode, the Instit ut ional Television Menu may be accessed by
pressing the MENU button. Though the specific items in the menu will vary, information similar to
the following will be displayed.
Menu Item Settings / Options
(MENU TITLE) SETUP MENU / MAIN MENU
LANGUAGE ENGLISH / ESPANOL / FRANCAIS
CHANNEL INSTALL >
CABLE TUNING ON / OFF
BRIGHTNESS - - - | - - - 31
COLOR - - - | - - - 31
CONTRAST - - - | - - - 31
SHARPNESS - - - | - - - 31
TINT - - - | | - - - 0
NOISE REDUCTION ON / OFF
SOUND MODE MONO / STEREO
SAP OFF / NO SAP / ON
AUDIO OUT FIXED / VARIABLE
BALANCE - - - | - - - 0
TREBLE - - - | - - - 31
BASS - - - | - - - 31
INCRED STEREO ON / OFF
AVL ON / OFF
VOLUME BAR ON / OFF
MIN VOLUME | - - - - - - 0
MAX VOLUME - - - - - - | 63
SWITCH ON VOLUME - - - | - - - 31
SWITCH ON CHANNEL CH. 1-125 / FRONT / AUX / S-VIDEO / CVI / STANDARD
POWER ON STANDARD / FORCE D
CHANNEL DISPLAY NUMBER / LABEL / ALL / NONE
KEYBOARD LOCK ON / OFF
ESP 1 – 99 / OFF
AUDIO / VIDEO MUTE OFF / BLACK / BLUE
EXT AUD / VID OUT ON / OFF
WELCOME MESSAGE >
CHANNEL GUIDE POWER ON / OFF / ON
REMINDER ON / OFF
3 DIGIT ENT RY ON / OFF
A/CH A/V SWITCH ON – OFF
CC OFF / CC-1 / CC-2 / CC ON MUTE
SAVE CC ON / OFF
V-CHIP MENU ITEM ON / OFF
SAVE V-CHIP ON / OFF
V-CHIP SETUP >
SLEEPTIMER OFF / 15 / 30 / 45 / 60 / 90 / 120 / 180 / 240
EXIT >
5. Aft er making changes to the setti ngs, t he EXI T option may be used to l eave the Instit utional
Television Menu.
Hardware Alignments
Figure: Mono Carrier (Top View) LS
Vg2 Adjustment
1. Enter SDAM:
2. Press the following key sequence on the remote control transmitter:
0-6-2-5-9-6-MENU
Do not allow the display to time out between entries while keying the sequence.
3. Use the MENU UP/DOWN keys to highlight the WHITE TONE sub menu.
4. Press the MENU LEFT or MENU RIGHT key to enter the WHITE TONE sub
menu.
5. In the WHITE TONE sub menu, press the MENU UP/DOW N keys to select
NORMAL RED, NORMAL GREEN, or NORMAL BLUE.
6. Use the MENU LEFT/RIGHT keys to set the values of NORMAL RED, NORMAL
GREEN and NORMAL BLUE to 40.
7. Press the MENU button twice to enter the normal user menu.
8. In the normal user menu, use the MENU UP/DOWN keys to highlight the
PICTURE sub menu (if necessary).
9. Press the MENU LEFT/RIGHT keys to enter the PICTURE sub menu.
10.Use the MENU UP/DOW N keys to select PICTURE. Be sure to record the
current value of PICTURE.
11.Use the MENU LEFT/RIGHT keys to set the value of PICTURE to zero.
12.Use the MENU UP/DOW N keys to select BRIGHTNESS. Be sure to record the
current value of BRIGHTNESS.
13.Use the MENU LEFT/RIGHT keys to set the value of BRIGHTNESS to minimum
(OSD just visible in a dark room).
14.Press the MENU button twice to return to the top level SDAM menu.
15.Press the STATUS/EXIT button to hide the SDAM onscreen display.
16.Connect the RF output of a video pattern generator to the antenna input.
17.Input a "black picture" test pattern to the television set.
18.Set the oscilloscope to 50 V/div and the time base to 0.2 milliseconds (external
triggering on the vertical pulse).
19.Ground the scope at the CRT panel and connect a 10:1 probe to one of the
cathodes of the picture tube socket (see schematic diagram B).
20.Measure the cut off pulse during first full l ine after the frame blanking (see Fig.
8-2). You will see two pulses, one being the cut off pulse and the other being the
white drive pulse. Choose the one with the lowest value; this is the cut off pulse.
21.Select the cathode with the highest VDC value for the alignment. Adjust the V
Cut-Off of this gun with the SCREEN potentiometer (see Fig. 8-1) on the LOT to
the correct value (see table below).
22.Press the STATUS/EXIT button to display the SDAM onscreen display.
23.Press the MENU button to enter the normal user menu.
24.In the normal user menu, use the MENU UP/DOWN keys to highlight the
PICTURE sub menu (if necessary).
25.Press the MENU LEFT/RIGHT keys to enter the PICTURE sub menu.
26.Use the MENU UP/DOWN keys to select PICTURE.
27.Use the MENU LEFT/RIGHT keys to reset the value of PICTURE to the original
value.
28.Use the MENU UP/DOW N keys to select BRIGHTNESS.
29.Use the MENU LEFT/RIGHT keys to reset the value of BRIGHTNESS to the
original value.
30.Press the MENU button twice to return to the top level SDAM menu.
31.Use the POWER button on the remote control transmitter or the POWER button
on the television set to turn off the television set. This will save the changes
made in SDAM.
Figure: V Cut-Off
Table: Cut-off Voltage, Large Screen
Screen Size
25/28Tesla, 25/28BLD+140V +/- 4V
Cut-off Voltage
20RF/21RF/25RF /29RF , 21RF Pi n-F r ee, 25"HF LA ,
25V/27V/32V/35V/ 25"/33"/28BLS, 29",29SF E U,
1. Connect the RF output of a video pattern generator to the antenna input.
2. Input a circle or crosshatch test pattern to the television set.
3. Press the AUTO PICTURE button on the remote control transmitter repeatedly to
choose PERSONAL or MOVIES picture mode.
4. Adjust the FOCUS potentiometer (see Fig. 8-1)until the vertical lines near the left
and right sides of the screen, and near the horizontal center of the screen, are at
minimum width without visible haze.
Software Alignments and Settings
The following options are performed in the Service Default Alignment Mode (SDAM).
SDAM is described in the "Service Modes, Error Codes and Fault Finding" section.
The following alignments are explained:
1. OPTIONS
2. TUNER
3. WHITE TONE
4. GEOMETRY
5. AUDIO
Options
Figure: Options Menu
Options are used to control the presence or absence of certain features and hardware.
How to change an Option Byte
An Option Byte represents a number of different options. Changing these bytes directly
makes it possible to set all options very quickly. All options are controlled via seven
option bytes.
To change Option Byte(s):
1. Enter SDAM:
Press the following key sequence on the remote control transmitter:
0-6-2-5-9-6-MENU
Do not allow the display to time out between entries while keying the sequence.
2. Use the MENU UP/DOWN keys to highlight the OPTIONS sub menu.
3. Press the MENU LEFT or MENU RIGHT key to enter the OPTIONS sub menu.
4. In the OPTIONS sub menu, press the MENU UP/DOWN keys to select OP 1
through OP 7.
5. Use the number keys on the remote control transmitter to enter a new value for
the selected option byte. The value must be entered as a three-digit value (for
example, "4" would be entered as "0-0-4").
6. The selected value must be between 0 and 255.
7. When all desired changes to the option bytes are made, press the MENU button
to return to the top level SDAM menu. This will save changes to the option byte
settings.
8. To ensure the option byte changes take effect: Turn the tele vision set OFF by
using the POWER button on the remote control transmitter or the local
keyboard. Disconnect the television set from AC power for at least ten seconds.
Reconnect the television set to AC power. Turn the television set ON by using
the POWER button on the remote control transmitter or the local keyboard.
* Option Byte Data for these m odels was not available at m anual release.
Refer to f ut ur e updates to thi s m anual regardi ng t hese model s.
Tuner
Note: Described alignments are only necessary when the NVM (part reference
number7602) is replaced.
Figure: Tuner Menu
IF PLL
This adjustment is auto-aligned. Therefore, no action is required.
AGC (AGC take over point)
1. Connect the RF output of a video pattern generator to the antenna input.
2. Input a color bar test pattern to the television set.
3. Set the amplitude of the video pattern generator to 10 mV and set the frequency
to 61.25 MHz (channel 3).
4. Connect a DC multimeter to pin 1 of the tuner(item 1000 on the main chassis).
5. Enter SDAM:
Press the following key sequence on the remote control transmitter:
0-6-2-5-9-6-MENU Do not allow the display to time out between entries while
keying the sequence.
6. Use the MENU UP/DOWN keys to highlight the TUNER sub menu.
7. Press the MENU LEFT/RIGHT keys to enter the TUNER sub menu.
8. Use the MENU UP/DOWN keys to select AGC.
9. Use the MENU LEFT/RIGHT keys to adjust the AGC value (default value is 27)
until the voltage at pin 1 of the tuner lies between 3.8V and 2.3V.
10.Press the MENU button to return to the top level SDAM menu.
11.To ensure the AGC change takes effect: Turn the television set OFF by using
the POWER button on the remote control transmitter or the local keyboard.
Disconnect the television set from AC power for at least ten seconds. Reconnect
the television set to AC power. Turn the television set ON by using the POWER
button on the remote control transmitter or the local keyboard.
SL (Slicing Level)
This adjustment sets the sync slicing level for non-standard signals.
SL should be turned ON to help correct picture instability in premium decoded cable
channels.
OFF: slicing level dependent on noise detector
ON: fixed slicing level of 70%
To adjust SL:
1. Enter SDAM:
Press the following key sequence on the remote control transmitter:
0-6-2-5-9-6-MENU Do not allow the display to time out between entries while
keying the sequence.
2. Use the MENU UP/DOWN keys to highlight the TUNER sub menu.
3. Press the MENU LEFT/RIGHT keys to enter the TUNER sub menu.
4. Use the MENU UP/DOWN keys to select SL.
5. Use the MENU LEFT/RIGHT keys to toggle SL "Off" and "On"
6. Press the MENU button to return to the top level SDAM menu.
7. To ensure the SL setting is saved: Turn the television set OFF by using the
POWER button on the remote control transmitter or the local keyboard.
Disconnect the television set from AC power for at least ten seconds. Reconnect
the television set to AC power. Turn the television set ON by using the POWER
button on the remote control transmitter or the local keyboard.
White Tone
Figure: White Tone Menu
The values of the black cut off le vel can be adjusted in the WHITE TONE sub menu.
Normally, no alignment is needed for WHITETONE, and the given default values are
used.
Default settings:
NORMAL (color temperature = 9600 K):
NORMAL RED = 40
NORMAL GREEN = 40
NORMAL BLUE = 40
To adjust NORMAL RED, NORMAL GREEN, and NORMAL BLUE:
1. Enter SDAM:
Press the following key sequence on the remote control transmitter:
0-6-2-5-9-6-MENU Do not allow the display to time out between entries while
keying the sequence.
2. Use the MENU UP/DOWN keys to highlight the WHITE TONE sub menu.
3. Press the MENU LEFT/RIGHT keys to enter the WHITE TONE sub menu.
4. Use the MENU UP/DOWN keys to select NORMAL RED, NORMAL GREEN, or
NORMAL BLUE.
5. Use the MENU LEFT/RIGHT keys to adjust the value of NORMAL RED,
NORMAL GREEN, or NORMAL BLUE.
6. When all desired changes to the WHITE TONE submenu values are made,
press the MENU button to return to the top level SDAM menu.
7. To ensure the WHITE TONE settings are saved: Turn the television set OFF by
using the POWER button on the remote control transmitter or the local
keyboard. Disconnect the television set from AC power for at least ten seconds.
Reconnect the television set to AC power. Turn the television set ON by using
the POWER button on the remote control transmitter or the local keyboard.
Geometry
The geometry alignments menu contains several Items for correct picture geometry
alignment.
1. Connect the RF output of a video pattern generator to the antenna input.
2. Input a crosshatch test pattern to the television set.
3. Set the amplitude of the video pattern generator to at least 1 mV and set the
frequency to 61.25 MHz (channel 3).
4. Press the AUTO PICTURE button on the remote control transmitter repeatedly to
choose PERSONAL or MOVIES picture mode.
5. Enter SDAM:
Press the following key sequence on the remote control transmitter:
0-6-2-5-9-6-MENU Do not allow the display to time out between entries while
keying the sequence.
6. Use the MENU UP/DOWN keys to highlight the GEOMETRY sub menu.
7. Press the MENU LEFT/RIGHT keys to enter the GEOMETRY sub menu.
8. Use the MENU UP/DOWN keys to highlight either the HORIZONTAL sub menu
or the VERTICAL sub menu.
9. Press the MENU LEFT/RIGHT keys to enter either the HORIZONTAL sub menu
or the VERTICAL sub menu.
10.Use the MENU UP/DOWN keys to select items in the HORIZONTAL sub menu
or the VERTICAL sub menu.
11.Use the MENU LEFT/RIGHT keys to adjust the values of items in the
HORIZONTAL and VERTICAL sub menus.
12.When all desi red changes to the HORIZ ONTAL and VERTICAL sub menu
values are made, press the MENU button twice to return to the top level SDAM
menu.
13.To ensure the GEOMETRY settings are saved: Turn the television set OFF by
using the POWER button on the remote control transmitter or the local
keyboard. Disconnect the television set from AC power for at least ten seconds.
Reconnect the television set to AC power. Turn the television set ON by using
the POWER button on the remote control transmitter or the local keyboard.
The following alignments can be performed in the GEOMETRY submenu:
Figure: Horizontal Menu
Horizontal:
Horizontal Parallelogram (HP) Aligns straight vertical lines at the top and the
bottom of the screen; vertical rotation round the center.
Horizontal Bow(HB) Aligns straight horizontal lines at the top and the bottom of the
screen; horizontal rotati on around the center.
Horizontal Shift(HSH) Aligns the horizontal center of the picture to the horizontal
center of the CRT.
East West Width(EWW) Aligns the width of the picture.
East Wes t Parabola(EWP) Aligns strai ght vertical lines at the sides of the screen.
Uppe r Corner Parabola (UCP) Aligns straight vertical lines in the upper corners of
the screen.
Lower Corner Parabola (LCP) Aligns straight vertical lines in the lower corners of
the screen.
East West Trapezium(EWT) Align straight vertical lines at the middle of the screen.
Figure: Vertical Menu
Vertical:
Vertical slope (VSL) Aligns the picture so the proportions are the same at the top
and bottom of the screen. This alignment must be performed first, before all
other vertical alignments. Turning SBL ON will assist in performing this
alignment.
Vertical Am plitude(VAM) Aligns the height of the picture (other vertical alignments
are NOT compensated).
Vertical S-Correction (VSC) Aligns the vertical linearity, so that the vertical intervals
of the grid-patterns are the same over the entire height of the screen.
Vertical Shift(VSH) Aligns the vertical center of the picture to the vertical center of
the CRT. After performing this alignment, it may be necessary to perform the
VAM alignment again.
Vertical Zoom(VX ) Adjusts picture height.
Service blanking(SBL) Turns the blanking of the lower half of the screen ON or
OFF (to be used in combination with the vertical slope alignment).
The table below lists the default GEOMETRY values for the different television sets.
Table: Default Geometry Values
Alignment
HPHor. Paralle logram 3133333133
HBHor. Bow3030303030
HSHHor. S hift3539393539
EWWEa st West Widt h3435353435
EWPEa st West Parabola 3322223322
Description20RFL260/37R
BTSC
NON-DBX
21PT839B/85R
BTSC DBX
27RFL260/37R
BTSC DBX
20RFL250/37R
BISONIC
21PT639A/85R
BISONIC
UCPUpper Corner
Parabola
LCPLower C orner
Parabola
EWTEast West
Trapezium
VSLVert. Slope3331313331
VAMVert. Amplitude3325253325
VSCVert. S -correction3235353235
VSHVert. S hift3521213521
VXVert. Zoom3325253325
3541413541
3541413541
4331314331
Audio
Figure: Audio Menu
No alignments are necessary for the AUDIO sub menu. Use the default values.
AF-M
Default value is 300.
A2T
TV A2 Threshold
Default value is 250.
To adjust AF-M:
1. Enter SDAM:
Press the following key sequence on the remote control transmitter:
0-6-2-5-9-6-MENU Do not allow the display to time out between entries while
keying the sequence.
2. Use the MENU UP/DOW N keys to highlight the AUDIO sub menu.
3. Press the MENU LEFT/RIGHT keys to enter the AUDIO sub menu.
4. Use the MENU UP/DOWN keys to select AF-M.
5. Use the MENU LEFT/RIGHT keys to adjust the value of AF-M to 300.
6. Press the MENU button to return to the top level SDAM menu.
7. To ensure the AF-M setting is saved: Turn the television set OFF by using the
POWER button on the remote control transmitter or the local keyboard.
Disconnect the television set from AC power for at least ten seconds. Reconnect
the television set to AC power. Turn the television set ON by using the POWER
button on the remote control transmitter or the local keyboard.
To adjust A2T:
1. Enter SDAM:
Press the following key sequence on the remote control transmitter:
0-6-2-5-9-6-MENU Do not allow the display to time out between entries while
keying the sequence.
2. Use the MENU UP/DOW N keys to highlight the AUDIO sub menu.
3. Press the MENU LEFT/RIGHT keys to enter the AUDIO sub menu.
4. Use the MENU UP/DOWN keys to select A2T.
5. Use the MENU LEFT/RIGHT keys to adjust the value of A2T to 250.
6. Press the MENU button to return to the top level SDAM menu.
7. To ensure the A2T setting is saved: Turn the television set OFF by using the
POWER button on the remote control transmitter or the local keyboard.
Disconnect the television set from AC power for at least ten seconds. Reconnect
the television set to AC power. Turn the television set ON by using the POWER
button on the remote control transmitter or the local keyboard.
Philips Consumer Electronics
Technical Service Data
Service and Quality
Service Publications Dept.
One Philips Drive
P.O. Box 14810
Knoxville, TN 37914
Manual 7629
Model no.: 27PS60S321
First Publish: 12740 T8
Rev. Date: 2002-06-06
Print Date: 7/8/2004
Parts List
REFER TO SAFETY GUIDELINES
SAFETY NOTICE:
HIMSELF WITH THE CHASSIS AND BE AWARE OF THE NECESSARY SAFETY PRECAUTIONS
TO BE USED WHEN SERVICING ELECTRONIC EQUIPMENT CONTAINING HIGH VOLTAGES.
CAUTION: USE A SEPARATE ISOLATION TRANSFORMER FOR THIS UNIT WHEN SERVICING
S = Safety Part Be sure to use exact replacement part.
CircuitDescription
Index of this chapter:
1. Introduction
2. Audio signal processing
3. Video signal processing
4. Synchronization
5. Deflection
6. Power supply
7. Control
8. Abbreviations
Note : For complete block diagrams a reference is made to Block diagram .
Page 1 of 32SPMS
Introduction
The S8/T8 chassis is a global TV chassisfor the model year 2001 and is used for TV sets with
screen sizesfrom 25” - 36” (large screen), in Super Flat,Real Flat and Wide Screen executions.
The standard architecture consists of a Main panel, aPicture Tube panel, a Side I/O panel and
a Top Controlpanel. In some executions, a Picture In Picture (PIP) panel is used.
The Main panel consists primarily of conventional components withhardly any surface mounted
devices.
7/8/2004
Page 2 of 32SPMS
Figure:
The functions for video processing, microprocessor (μP)and teletext (TXT) decoder are
combined in one IC (TDA958xH), theso-called Ultimate One Chip (UOC). This chip is (surface)
mountedon the copper side of the LSP.
7/8/2004
Page 3 of 32SPMS
Figure:
The S8/T8 is divided into 2 basic systems, i.e.mono and stereo sound. While the audio
processing for the mono soundis done in the audio block of the UOC, an external audio
processingIC is used for stereo sets.
The tuning system features 181 channels with on-screen display.The main tuning system uses
a tuner, a microcomputer, and a memoryIC mounted on the main panel.
The microcomputer communicates with the memory IC, the customerkeyboard, remote
receiver, tuner, signal processor IC and the audiooutput IC via the I 2 Cbus. The memory IC
retains the settings for favorite stations, customer-preferredsettings, and service / factory data.
The on-screen graphics and closed caption decoding aredone within the microprocessor, and
then sent to the signal processorIC to be added to the main signal.
The chassis utilizes a Switching Mode Power Supply (SMPS) forthe main voltage source. The
chassis has a ‘hot’ ground referenceon the primary side and a cold ground reference on the
secondaryside of the power supply and the rest of the chassis.
Audio Signal Processing
Block diagram Audio
Stereo
In stereo sets, the signal goes via the SAWfilter (position 1002), to the audio demodulator part
of the UOCIC 7200. The audio output on pin 48 goes to the stereo decoder 7831or 7861. The
switch inside this IC selects either the internal decoderor an external source.
There are two stereo decoders used:
1. a BTSC DBXstereo/SAP decoder (MSP34X5 at position 7831) for the highestspecified
sets and
2. a BTSC non-DBX stereo decoder (TDA 9853 at position 7861)for BTSC Economic.
The output is fed to the to the audio amplifier (AN7522at position 7901). The volume level is
controlled at this IC (pin9) by a control line (VolumeMute) from the microprocessor. The
audiosignal from 7901 is then sent to the speaker / headphone outputpanel.
Mono
7/8/2004
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