Sharp SX76NF8 User manual

1
SX76NF8
WARNING
The chassis in this receiver is partially hot. Use an isolation transformer between the line cord plug and power
receptacle, when servicing this chassis. To prevent electric shock, do not remove cover. No user – serviceable
parts inside. Refer servicing to qualified service personnel.
SERVICE MANUAL
In the interests of user-safety (Required by safety regulations in some countries) the set should be restored
to its original condition and only parts identical to those specified should be used.
MODEL SX76NF8
SHARP CORPORATION
COLOUR TELEVISION
Chassis No. GA-20X
Page
CONTENTS
»SPECIFICATIONS .............................................2
»IMPORTANT SERVICE NOTES........................2
»ADJUSTMENT PRECAUTIONS........................3
»TROUBLE SHOOTING TABLE .........................8
»WAVEFORMS..................................................12
»CHASSIS LAYOUT ..........................................14
»BLOCK DIAGRAM...........................................16
»DESCRIPTION OF SCHEMATIC DIAGRAM ..18
»SCHEMATIC DIAGRAM
ËCRT UNIT.....................................................19
ËMAIN UNIT ...................................................20
ËCONTROL UNIT ..........................................26
ËDF UNIT .......................................................28
ËLED UNIT .....................................................29
ËKEY UNIT.....................................................29
ËSUB WOOFER UNIT ...................................30
Page
»PRINTED WIRING BOARD ASSEMBLIES .....31
»REPLACEMENT PARTS LIST
ËELECTRICAL PARTS
MAIN UNIT ...................................................38
CRT UNIT.....................................................43
CONTROL UNIT ..........................................44
DF UNIT .......................................................45
LED UNIT .....................................................45
SUB WOOFER UNIT ...................................45
KEY UNIT.....................................................45
ËMISCELLANEOUS PARTS..........................46
ËSUPPLIED ACCESSORIES.........................46
ËPACKING PARTS.........................................46
ËCABINET PARTS .........................................46
ËCABINET PARTS LOCATION......................46
»PACKING OF THE SET...................................47
FEATURE
ËFull Auto Channel Preset and Auto Channel Skip
Ë100 CH Program Memory
ËCATV (Hyper Band) Ready
<Used Frequency Synthesizer Tuner>
ËHigh Contrast Picture
ËTELETEXT(10 page)
English / German / French / Spanish / Italian
/ Swedish / Dutch / portuguese
ËON Timer/OFF Timer
ËBlue Back Noise Mute
ËWhite Temperature Adjustment
ËChild Lock
ËAuto Sound Limiter
ËHeadphone Terminal
ËStereo (NICAM / IGR) Decoder
ËRotation adjustment (picture tilt adjustment)
ËComponent Input Terminal
S13V5SX76NF8/

2
2-1 2-2
SX76NF8
SPECIFICATIONS
Convergence .................................................................Self Convergence System Focus ............................................................Electrostatic Focus High Bi-Potential Sweep Deflection......................................................................................Magnetic Intermediate Frequencies Picture IF Carrier ..................................................................................38.9MHz Sound IF Carrier Frequency 5.5MHz ..............................................................................................33.4MHz Colour Sub-Carrier Frequency............................................................34.47MHz Power Input......................................................................... AC 220 ~ 240V 50 Hz Power Consumption ......................................................................................140W Audio Power Output Rating ............................................5W + 5W + 10W(at Max.) Speaker Size.............................................................................. 11 x 5 cm Elliptic (2 pcs) 10cm Round (1pc) Voice Coil Impedance..............................................................4 ohm (11 x 5cm) 8 ohm (10cm) Aerial Input Impedance VHF/UHF ............................................................................ 75 ohm Unbalanced Receiving System (PAL-B/G) VHF.......................................................................................AU 0 thruAU 12 ch UHF ....................................................................................AU 28 thru AU 69 ch Receiving Frequency VHF-Channels ......................................................... 44.25MHz thru 463.25MHz UHF-Channels....................................................... 471.25MHz thru 863.25MHz Dimensions................................................................................... Width: 880.0mm
Height: 566.0mm
Depth: 545.0mm
Weight(approx): 54.0 kg
Cabinet material ....................................................................................All Plastics
Specifications are subject to change without prior notice.
IMPORTANT SERVICE NOTES
Maintenance and repairing of this receiver should be done by quali- fied service personnel only. SERVICE OF HIGH VOLTAGE SYSTEM AND PIC- TURE TUBE
When servicing the high voltage system, remove static charge from it by Connecting a 10K ohm Resistor in series with an insulated wire(such as a test probe) between picture tube dag and 2nd anode lead. (AC line cord should be disconnected from AC outlet.) 1. Picture tube in this receiver employs integral implosion protection. 2. Replace with tube of the same type number for continued safety. 3. Do not lift picture tube by the neck. 4. Handle the picture tube only when wearing shatterproof goggles and after discharging
the high voltage completely.
X-RAY This receiver is designed so that any X-Ray radiation is kept to an absolute Minimum. Since certain malfunctions or servicing may produce potentially hazardous radiation with prolonged exposure at close range, the following precautions should be observed:
1. When repairing the circuit, be sure not to increase the high voltage to more than 34.5kV(at
beam 0
µ
A) for the set.
2. To keep the set in a normal opeartion , be sure to make it function on 30.5kV
±
1.5kV(at
beam 1800
µ
A) in the case of the set. The set has been factory - Adjusted to the above-
mentioned high voltage.
*If there is a possibility that the high voltage fluctuates as a result of the repairing,
never forget to check for such high voltage after the work.
3. Do not substitute a picture tube with unauthorizerd types and/or brands which may
cause excess X-ray radiation.
BEFORE RETURNING THE RECEIVER Before returning the receiver to the user, perform the following safety Checks. 1. Inspect all lead dress to make certain that leads are not pinched or that hardware is not
lodged between the chassis and other metal parts in the receiver.
2. Inspect all protective devices such as non-metallic control knobs, insulating fishpapers,
cabinet backs, adjustment and compartment covers or shields, isolation resistor- ca- pacity networks, mechanical insulators etc.

3
3-1 3-2
SX76NF8
ADJUSTMENT PRECAUTIONS
All adjustments to this chassis, except for focus, are carried out in the Service Mode. Service Mode
The Service Mode is provided to enable the engineer to correctly set up the receiver to the CRT fitted in the set. Note that these adjustments may vary from one receiver to another. To enter the Service Mode, carry out the following procedure. 1.Connect a test pattern to the antenna terminal. 2.Tune the receiver to this signal. 3.Turn the receiver off using the mains switch. 4.Press volume down and channel up buttons on the front of
the receiver at the same time.
5.Keeping these buttons pressed, turn the mains on. 6.When the set starts up it will be in Service Mode. 7.Release the two buttons. »Use the channel up and down buttons to move between the options. »Use the volume control buttons to change the data. »To store the data, use the stand-by button on the remote control. »To exit the Service Mode, turn the receiver off using the mains switch.
When the Service Mode is entered the following On Screen Display appears
SERVICE SOFTWARE
SW on: XXXX SW off: XXXX Hours ON: XXXX
The figures displayed in the XXXX locations are hexadecimal representations of the number of times that particular function has been executed. For example if the hexadecimal number displayed after SW ON was 0E4A, this would correspond to the receiver being turned on 3658 times.
Adjustment menu: The following adjustments can be carried out in the Service Mode.
»Horizontal Shift »Blue Gain »East West Width »Red Cut Off »Pin Phase »Green Cut Off »Pin Amp (Amplitude) »Blue Cut Off »Corner Amplitude »Alter NVM Pag (Page) »Corner Symmetry »Alter NVM Pos (Position) »Vertical Linearity »Alter NVM Val (Value) »Vertical Angle »Teletext Mix Mode Contrast »Vertical Bow »Teletext Contrast »Vertical Amplitude »OSD Contrast »S Correction »DVCO Adjustment (Only PAL) »Vertical Shift »DVCO Adjustment (Only NTSC) »Red Gain »AGC Adjustment »Green Gain »Rotation Inspection
»INTIAL On/Off
Note that the receiver should be set to FULLMODE before carrying out any geometry adjustments. This can be achieved by pressing the widescreen mode button on the remote control until FULL MODE appears on the OSD.This can only be done out of the Service Mode. Detailed instructions on how to execute these are given on the following pages.
Front Top of front cabinet
Changing NVM Data To change the data contained within the Non Volatile Memory, it is necessary to first select the page the data is stored in, then the position and finally to change the data itself. The procedure below outline this process. 1. Press the channel up/down buttons and ALTER NVM PAG appears, use the volume up/down buttons to change this
data (it is shown in hexadecimal format).
2. Press the channel up button and ALTER NVM POS appears use the volume up/down buttons to change this data (it
is shown in hexadecimal format).
3. Press the channel up button and ALTER NVM VAL appears, use the volume up/down buttons to change this data (it
is shown in hexadecimal format).
4. Once this data has been set, press the stand-by button to store. 5. If another NVM value has to be changed, use the channel down button to select the page or position and repeat as
necessary.
Note: DO NOT change any NVM data, unless you have been adviced to do so by a Sharp representative. If data is incorrectly changed, serious damage may occur to hte receiver.

4
4-1 4-2
SX76NF8
PIF ADJUSTMENT
NO
1ADJUSTMENT POINT
RF-AGC ADJUSTMENT (I2C BUS CONTROL)
ADJUSTMENT CONDITION / PROCEDURE
(1) Receive signal. E-12cH Signal strength: 57 ±1dBµV (50 ohm open) (2) Call "AGC" mode in service mode. (3) Push "power button", automatically adjust.
WAVEFORM OR OTHERS
Note: For the 50 ohm signal strength gauge, when not using 50/75 impedance adapter, signal strength is 57±1dBµV(50 ohm open),
instead of 59 ±1dBµV(75 ohm open).
precaution:The loss of using impedance adapter.
CUT OFF, BKGD ADJUSTMENT
NO
1ADJUSTMENT POINT
AGING ADJUSTMENT CONDITION / PROCEDURE
(1) Receive PR-99ch (BLUE BACK OFF), "NOISE PICTURE" (2) Aging 30 minutes.
WAVEFORM OR OTHERS
1 CRT CUTOFF
ADJUSTMENT (1) Receive 50Hz Monoscope Pattern Signal.
(2) Set Picture Normal condition. (3) Select full mode. (4) Call "RED GAIN" mode in service mode. (5) Adjust SCREEN VR, so that the value of OSD reach 50h ±8h. (Fig.1)
07 52 53 54 13 50 51 52
Fig.1 The value of this point
2WHITE BALANCE
SERVICE MODE ADJ (1) Receive the "WHITE/BLACK" Pattern SIGNAL.
(2) Press R/C to set Picture NORMAL condition. (3) Select full mode. (4) Call "*** GAIN/***CUT OFF" mode in service mode. (5) Adjust the "RED GAIN","GREEN GAIN","BLUE
GAIN","GREEN CUT OFF", and "BLUE CUT OFF" data to have a colour temperature of 12300°K (white).
3Max Beam Check (1) Receive 50Hz Monoscope Pattern Signal.
(2) Press R/C to set Picture NORMAL condition. (3) Select full mode. (4) Connect the DC miliammeter between R611(10KΩ) (Full Scale: 3mA Range) (5) Beam current must be within 1600 ±100µA.
Refer to SHIPPING SETTING & CHECKING. • 12300°KX : 0.272±0.010
Y : 0.275±0.010
(MINOLTA COLOUR ANALYZER CA-100) *Note: Above Data can be UP/DOWN by
Volume Key. HIGH 100cd/m2 ±10cd/m2
LOW 10.0cd/m2 ±1cd/m2
HORIZONTAL, VERTICAL, DEFLECTION LOOP ADJUSTMENT.
NO
1 2 3 4 5 6 7 8 9
10 11 12
ADJUSTMENT POINT
1) 50Hz FULL V. LINEARITY (I2C BUS CONTROL) VERTICAL SHIFT (I2C BUS CONTROL) VERTICAL AMP. (I2C BUS CONTROL) HORIZONTAL SHIFT (I2C BUS CONTROL) EAST-WAST WIDTH (I2C BUS CONTROL) PIN PHASE (I2C BUS CONTROL) PIN AMP (I2C BUS CONTROL)
CORNER AMPLITUDE (I2C BUS CONTROL) CORNER SYMMETRY (I2C BUS CONTROL) VERTICAL ANGLE (I2C BUS CONTROL) VERTICAL BOW (I2C BUS CONTROL) S CORRECTION (I2C BUS CONTROL) 2) 50Hz CINEMA 3) 60Hz FULL 4) 60Hz CINEMA
ADJUSTMENT CONDITION / PROCEDURE
(1) Press R/C to set Picture NORMAL condition. (2) Select full mode. *Receive 50Hz Monoscope Pattern Signal. (1) Call the "VERTICAL LINEARITY" mode. (2) Increase or decrease "VERTICAL LINEARITY" by
Volume key till the horizontal line in the center of monoscope is just at the position where the blanking starts.
(1) Call the "VERTICAL SHIFT" mode. (2) Increase or decrease "VERTICAL SHIFT" by Volume key
till the picture is centered.
(1) Call the "VERTICAL AMPLITUDE" mode. (2) Increase or decrease "VERTICAL AMPLITUDE" by
Volume key to set overscan of 8% typical.
Adjustment Spec 8% range +1% -1% (1) Call the "H-CENT" mode. (2) Increase or decrease "H-CENT" byVolume Key to center
the picture horizontal.
(1) Call the "EAST-WASTWIDTH" mode. (2) Increase or decrease "EAST-WASTWIDTH" byVolume
key to set overscan of 8% typical.
Adjustment Sepc 8% range +1% -1% *Receive 50Hz Cross-Hatch Pattern Signal. (1) Call the "PIN PHASE" mode. (2) Increase or decrease "PIN PHASE" byVolume key. (1) Call the "PIN AMP" mode. (2) Increase or decrease "H-CENT" byVolume key. (1) Call the "CORNER AMPLITUDE" mode. (2) Increase or decrease "CORNER AMPLITUDE" by
Volume key.
(1) Call the "CORNER SYMMETRY" mode. (2) Increase or decrease "CORNER SYMMETRY" by
Volume key.
(1) Call the "VERTICAL ANGLE" mode. (2) Increase or decrease "VERTICAL ANGLE" by Volume
key.
(1) Call the "VERTICAL BOW" mode. (2) Increase or decrease "VERTICAL BOW" by Volume key. (1) Call the "S CORRECTION" mode. (2) Increase or decrease "S CORRECTION" byVolume key. Adjust items NO1---NO12, same as 50Hz FULL In CINEMA mode V-SIZE Adjustment Spec 25% range +1% -0% H-SIZE Adjustment Spec 8% range +1% -1%
WAVEFORM OR OTHERS
Note: V. LINEARITY is the fixation values. No adjustment. VERTICAL SHIFT andVERTICAL AMP. 2mm > |A-B| E-5 2mm > |C-D| A face is for south Adjustment Spec 8.0% range +1% -1% at the upper side of the geometry center and the lower side of the geometry center CORNER SYMMETRY is the fixation values. No adjustment VERTICAL ANGLE is the fixation values. No adjustment VERTICAL BOW is the fixation values. No adjustment Note: Refer to PAGE 9/11
AB CD

5
5-1 5-2
SX76NF8
FOCUS ADJUSTMENT
NO
1ADJUSTMENT POINT
FOCUS ADJUSTMENT CONDITION / PROCEDURE
(1) Receive the "Monoscope Pattern" signal. (2) Press R/C to set Picture NORMAL condition. (3) Select full mode. (4) Adjust the focus control to get the best focusing.
(Refer to Adjustment Point as right drawing, SX76NF8 and SX66NF8)
WAVEFORM OR OTHERS
(Adjusted point)
PROTECTOR OPERATION CHECKING
NO
1 2
ADJUSTMENT POINT
H•V PROTECTOR OTHER PROTECTOR
ADJUSTMENT CONDITION / PROCEDURE
(1) Receive "Monoscope Pattern" signal. (2) Connect output of Bias Box to D607 cathode (3) Set voltage of Bias Box to 18V and make sure the
protector is not work.
(4) Set voltage of Bias Box to 27V, and make sure the
protector is work.
(1) Once finish rectified Electrolytic Capacitor short testing
in + B line, check all possible damaged components on +B line. (Use random selected set for inspection)
WAVEFORM OR OTHERS
A/V INPUT AND OUTPUT CHECKING
NO
1 2 3 4 5 6
ADJUSTMENT POINT
AV OUTPUT CHECK AV-1 INPUT CHECK AV-2 INPUT CHECK AV-1 Component INPUT CHECK FRONT INPUT CHECK FRONT S-Terminal INPUT CHECK
ADJUSTMENT CONDITION / PROCEDURE
(1) Receive the "PAL Color Bar" signal (100% White Color
Bar, Sound 400Hz 100% Mod)
(2) Terminate the Video output with a 75 ohm impedance.
Make sure the output is as specified (1.0Vp-p ±3dB)
(3) Terminate the Audio output with a 10 Kohm impedance.
Make sure the output is as specified (2.61Vp-p ±3dB)
Check of AV Check of AV Check of AV Check of AV Check of AV
WAVEFORM OR OTHERS
50
Adjust these Horizontal and Vertical lines (SX76NF8) Adjust at "50" position (SX66NF8)
FUNCTION OPERATION CHECKING (1) (VIDEO & AUDIO)
NO
1 2 3 4 5 6 7 8 9
ADJUSTMENT POINT
CONTRAST COLOUR BRIGHTNESS SHARPNESS TINT ECO MODE COMB FILTER NTSC HUE NORMAL
ADJUSTMENT CONDITION / PROCEDURE
(1) Receive "Monoscope Pattern" signal. (2) Set P-Mode to select CONTRAST. (3) Press Volume Up/Down key to check whether the
CONTRAST effect is OK or not.
(1) Receive "Color Bar" signal. (2) Set P-Mode to select COLOUR. (3) Press Volume Up/Down key to check whether the
COLOUR effect is OK or not.
(1) Receive "Monospcope Pattern" signal. (2) Set P-Mode to select BRIGHTNESS. (3) Press Volume Up/Down key to check whether the
BRIGHTNESS effect is OK or not.
(1) Receive "Monoscope Pattern" signal. (2) Set P-Mode to select SHARPNESS. (3) Press Volume Up/ Down key to check whether the
SHARPNESS effect is OK or not.
(1) Receive "Monoscope Pattern" signal. (2) Set PICTURE to TINT select. (3) Press Volume Up/Down key to check TINT Option,
STANDARD: NORMAL SETTING, WARM for more REDDISH direction changing, COOL for more BLUISH direction changing.
(1) Receive "Monoscope Pattern" signal. (2) Set P-Mode to select ECO MODE. (3) Press Volume Up/Down key to check whether the ECO
MODE effect is OK or not.
(1) Receive "Color Bar" signal. (2) Set P-Mode to select COMB FILTER. (3) Press Volume Up/Down key to check whether the COMB
FILTER effect is OK or not.
(1) INPUT "NTSC Color Bar" signal from AV-input. (2) Set P-Mode to select NTSC HUE.. (3) Press Volume Up/Down key to check whether the NTSC
HUE effect is OK or not.
(1) In PICTURE Mode, select NORMAL and press menu
button all the settings will be present to normal setting.
(Normal setting value for every mode).
CONTRAST : 80% COLOUR : 50% BRIGHTNESS : 50% SHARPNESS : 50% TINT : 50%
WAVEFORM OR OTHERS
Notes: If nothing is display mean contrast, colour, bright, tint, sharpness are all normal setting.

6
6-1 6-2
SX76NF8
CHECKING FUNCTION OPERATION (2) (VIDEO & AUDIO) CONTINUED
NO
10 11 12 13 14 15
ADJUSTMENT POINT
VOLUME BALANCE BASS TREBLE SOUND IDENT DYNAMIC BASS
ADJUSTMENT CONDITION / PROCEDURE
(1) Receive "Monoscope Pattern" signal. (2) Set S-Mode to select VOLUME. (3) Press Volume Up/Down key to check whether the
VOLUME effect is OK or not.
(1) Receive "Monoscope Pattern" signal. (2) Set S-Mode to select BALANCE. (3) Press Volume Up/Down key to check whether the Left-to
-Right BALANCE effect is OK or not.
(1) Receive "Monoscope Pattern" signal. (2) Set S-Mode to select BASS. (3) Press Volume Up/Down key to check whether the BASS
effect is OK or not.
(1) Receive "Monoscope Pattern" signal. (2) Set S-Mode to select TREBLE. (3) Press Volume Up/ Down key to check whether the
TREBLE effect is OK or not.
(1) Receive "Monoscope Pattern" signal. (2) Set S-Mode to select SOUND IDENT. (3) Press Volume Up/Down key to check whether the
SOUND IDENT effect is OK or not.
(1) Receive "Monoscope Pattern" signal. (2) Set S-Mode to select DYNAMIC BASS. (3) Press Volume Up/Down key to check whether the
DYNAMIC BASS effect is OK or not.
WAVEFORM OR OTHERS
CHECKING FUNCTION OPERATION (3) (VIDEO & AUDIO) CONTINUED
NO
16 17 18 19
ADJUSTMENT POINT
VOLUME Headphone BALANCE Headphone BASS Headphone TREBLE Headphone
ADJUSTMENT CONDITION / PROCEDURE
(1) Connect Headphone (2) Set S-Mode to select VOLUME in headphone mode. (3) Press Volume Up/Down key to check whether the
VOLUME effect is OK or not.
(1) Connect Headphone. (2) Set S-Mode to select BALANCE in headphone mode. (3) Press Volume Up/Down key to check whether the Left-to
-Right BALANCE effect is OK or not.
(1) Connect Headphone. (2) Set S-Mode to select BASS in headphone mode. (3) Press Volume Up/Down key to check whether the BASS
effect is OK or not.
(1) connect Headphone. (2) Set S-Mode to select TREBLE in headphone mode. (3) Press Volume Up/ Down key to check whether the
TREBLE effect is OK or not.
WAVEFORM OR OTHERS
CHECKING FUNCTION OPERATION (WIDE MODE)
NO
1 2 3
ADJUSTMENT POINT
WIDE MODE V-SIZE in wide mode V-SCROLL in wide mode
ADJUSTMENT CONDITION / PROCEDURE
(1) Receive "Monoscope Pattern" signal. (2) Press WIDE key to check change WIDE mode AUTO/PANORAMA/FULL/NORMAL/ZOOM14:9/CINEMA (1) Receive "Monoscope Pattern" signal. (2) Select PANORAMA, ZOOM14:9, and CINEMA mode. (3) Select V-SIZE, Press Volume Up/Down key to check
whether the V-SIZE effect is OK or not.
(1) Receive "Monoscope Pattern" signal. (2) Select PANORAMA, ZOOM14:9, and CINEMA mode. (3) Select V-SCROLL, Press Volume Up/Down key to check
whether the V-SCROLL effect is OK or not.
WAVEFORM OR OTHERS

7
7-1 7-2
SX76NF8
CHECKING FUNCTION OPERATION (TEXT MODE)
NO
1 2
ADJUSTMENT POINT
TEXT TEXT key
ADJUSTMENT CONDITION / PROCEDURE
(1) Receive E-12ch signal. (2) Press TEXT key to check changeTEXT mode /
SPLIT SCREEN mode / TELETEXT mode / MIXED mode.
(1) Receive E-12ch signal. (2) Press HALF PAGE, HOLD, REVEAL, CLOCK, CANCEL,
LIST, INDEX, and RESET key to check whether each effect is OK or not.
(3) Select V-SIZE, Press Volume Up/Down key to check
whether the V-SIZE effect is OK or not.
WAVEFORM OR OTHERS
PURITY AND CONVERGENCE ADJUSTMENT
NO
1ADJUSTMENT POINT
DY location (YPB) adjustment procedure
ADJUSTMENT CONDITION / PROCEDURE
(1) Turn on the set to make coarse adjustments to the CRT
cut-off, white balance, etc.as well as the purity static convergence.
(2) To improve the purity adjustment accuracy, perform
coarse adjustments to the H-SIZE/center, V-SIZE/LIN and side pin.
(3) Enter the video mode to set the beam current to the
standard value below using the screenVR.(Or it is possible to use the noise signal of an empty channel.) Age the set for more than 30 minutes with the following current.
Standard value of beam current:1000µA ±200µA
(4) Receive the monoscope signal to adjust the cut-off
voltage.
Consequently, adjust the contrast, color level and then
set the beam current to the above standard value.
Age the set for more than 2 minutes. Note: If other adjustments between step 3 and 4 (the
area marked by *) affect the conditions of the beam current, complete the adjustment for each point within 2 minutes, which is not included in the aging time).
* Perform the adjustments in an earth magnetism room
with Bh and Bv set to 0.20G and -0.50G respectively.
(5) Under the above conditions, move DY and the purity
magnet to make the following adjustments.
- 1. SetYPB of DY to 2.5 mm temporarily. - 2. Adjust the center to A rank by moving the purity
magnet.
- 3. Insert a temporary wedge to balance DY vertically. - 4. Move DY back and forth to set L and R to the
standard value below.(Apply to the purity correction magnet if L and R are imbalanced.)
- 5. Correct the center to "AB rank" if the L and R are
imbalanced.
- 6. After making sure the landing is properly positioned,
fix DY.
Note: Preliminary adjustments are made to set L and R
to the standard value after convergence adjustment.
Standard value: -25 µm ±5 µm at the 90 mm point
WAVEFORM OR OTHERS
Purity adjustment
Aging for more than 2 minutes
Aging for more than 30 minutes
Raster output
PURITY AND CONVERGENCE ADJUSTMENT (Continued)
NO
2
ADJUSTMENT POINT
Peripheral landing correction
ADJUSTMENT CONDITION / PROCEDURE
(1) Place the set in a magnetic room with the horizontal line
and vertical line set to 0G and - 0.5G respectively, and receive red monochrome.
(2) After a complete external; demagnetization, generate a
horizontal magnetic field of ±10000nT (0.1G) and apply
the purity correction magnet to the multi-colored areas. Check blue monochrome equally.
(3) Return the magnetic field to zero and perform a
complete demagnetization.
(4) Generate a reverse horizontal magnetic field, check red
and blue monochrome and apply the magnet to multi- colored areas.
(5) After correcting the magnet in step 4, check the reverse
magnetic field again.
3 Directional tolerance
check (1) Place the set in a magnetic room the horizontal line and
vertical line set to 0.2G and - 0.5G respectively, and receive red monochrome.
(2) Move the set from side to side at the four points of the
compass to check the status of the multiple colors and ensure L and R are well-balanced.
(3) Apply to the purity correction magnet if L and R are
imbalanced.
(4) If the magnet was applied in step 3, check from other
directions equally.
WAVEFORM OR OTHERS
4 Convergence
adjustment procedure (1) Set the video adjustment level to normal, and receive a
crosshatch pattern.
(2) Center convergence adjustment
Superimpose RGB of the screen center area for
optimization, by using the 4 pole and 6 pole of the purity magnet. Superimpose the red and blue by the 4 pole magnet, the green and magenta by the 6 pole magnet. As for vertical lines, avoid setting the red line to the left, blue to the right.
(3) Peripheral convergence adjustment
Combine the following item with the ferrite sheet to make
optimal adjustments.
1.XV cross
Rotate the variable coil on the DY PWB for optimization.
2.YH cross
Adjust with the volume on the DY PWB. If peripheral PQH is oversized, correct with the ferrite
sheet or by shaking slightly.
3.XH,YV
Use the dedicated correction strip to correct them.
YH YV
XV

SX76NF8
8
TROUBLE SHOOTING TABLE
NO PICTURE
Does the snow noise appear on the CRT at max contrast and brightness control?
Does approx.30V appear at pin (9) of TU201(tuner) Check L204, D606 and
R618
Check TU201 and their peripheral parts.
Check pin(1) and (2) of IC201
Check pin(51) of IC 1001 Does noise or signal appear?
Check IC1001 RGB output Normal?
Check pin(1), (2) and (3) of IC850 Signal or Noise?
Check R616(Heater), Screen connection and Peripheral circuits of T602(FBT) and CRT
Check TU201(tuner), SF202 and Peripheral parts.
Check IC201, Q201 and their Peripheral circuits.
Check IC1001 and their Peripheral circuits.
Check "CJ" connection, IC850 and their Peripheral circuits
Snow noise increase No Snow noise
(Noise or signal appear)
(Noise)
(Signal)

9
SX76NF8
TROUBLE SHOOTING TABLE
NO SOUND
Check sound setting by R/C. Siganl should be received.
Check C1302(C1309) Voltage
Approx. 15(-15V)
Check IC1301, IC1302 and Speaker
0V
Check L1302, L1303 D752 and D753

SX76NF8
10
TROUBLE SHOOTING TABLE
NO FUNCTION (NO SOUND AND NO PICTURE)
Is D2201(LED) on a light?
Check IC 1001 94pin INPUT
Check C755 Voltage
Immediately appear approx. 145V, and turn to 0V soon.
Check C752 Voltage
Check C715Voltage
Refer to "No Picture", trouble shooting
Check IC701, Q702 and T703
Check IC1001, IC1003, IC301, IC201, TU201(Refer to LED FLASHING CODES)
GREEN RED
Approx. 320V
Completely 0V
No Input Pulse
FLASHIN
Check D754 and IC751
Check Vertical Circuit
Check Q1012, D1016 and SP wire "SS" connection.
0V
Check R718, F2001 and "AA" connection
0V
Green Green Green Red Red Red
No Light
Immediately appear approx. 8V, and turn to 0V soon.
Check D752, D753, C756, C757 and IC752
LED FLASHING CODES If the TV set does not work and the power LED is flashing "Red <=>Green", follow the sequence according to the information below, as a guide to fault finding. 1.Unable to read or write into NMV;66% Green,33% Red twice and Red for a second. 2.MSP failure;66% Green,33% Red for three times and Red for a second. 3.VCT failure;66% Green,33% Red for four times and Red for a second.

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TROUBLE SHOOTING TABLE
NO VERTICAL SCAN
Check the Voltage at pin(15)(1) of IC502
Normal approx. 14V
Check IC502 and related circuits
Check D601, D605, R608 and R614
Check IC1001 and peripheral parts
Check vertical trigger pulse at pin(12)(13) of IC502

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WAVE FORMS
12 3
4 5 6
789
10 11 12

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13 14 15
16 17 18
19 20 21
22 23 24

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CHASSIS LAYOUT

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BLOCK DIAGRAM

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DESCRIPTION OF SCHEMATIC DIAGRAM
SAFETY NOTES:
1. DISCONNECT THE AC PLUG FROM THE AC OUTLET BEFORE
REPLACING PARTS.
2. SEMICONDUCTOR HEAT SINKS SHOULD BE REGARDED AS
POTENTIAL SHOCK HAZARDS WHEN THE CHASSIS IS OP-
ERATING.
IMPORTANT SAFETY NOTICE:
PARTS MARKED WITH “ å ” ( ) ARE IMPORTANT FOR
MAINTAINING THE SAFETY OF THE SET. BE SURE TO RE-
PLACE THESE PARTS WITH SPECIFIED ONES FOR MAINTAIN-
ING THE SAFETY AND PERFORMANCE OF THE SET.
SERVICE PRECAUTION:
THE AREA ENCLOSED BY THIS LINE ( ) IS DIRECTLY
CONNECTED WITH AC MAINS VOLTAGE.
WHENSERVICING THEAREA, CONNECTANISOLATINGTRANS-
FORMER BETWEEN TV RECEIVER AND AC LINE TO ELIMINATE
HAZARD OF ELECTRIC SHOCK.
NOTES:
1. The unit of resistance “ohm” is omitted.
(K = 1000 ohms, M = Meg ohm).
2. All resistors are 1/16 watt, unless otherwise noted.
3. All capacitors are µ F, unless therwise noted. (P = µµ F).
VOLTAGE MEASUREMENT CONDITIONS:
1. Voltage in parenthesis measured with no Signal.
2. Voltages without parenthesis measured with PAL Colour-Signal.
3. All the voltages in each point are measured with high impedence
volt-meter.
WAVEFORM MEASUREMENT CONDITIONS:
1. Colour bar generator signal of 2.0V peak to peak applied at Base
of Video Buffer Amp. Q254.
2. Approximately 4.0 V AGC bias.

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SCHEMATIC DIAGRAM

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