Sharp SX-68JS7 SX-68JS9 User manual

1
SX-68JS7
SX-68JS9
SERVICE MANUAL
SHARP CORPORATION
COLOURTELEVISION
Chassis No. SP-60
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.
WARNING
Intheinterestsofuser-safety(Requiredbysafetyregulationsinsomecountries)thesetshouldberestoredtoitsoriginal
condition and only parts identical to those specified should be used.
CONTENTS
Page
• FEATURES..........................................................2
• SPECIFICATIONS ...............................................2
• IMPORTANT SERVICE NOTES ......................... 3
• ADJUSTMENT PRECAUTIONS ......................... 3
• SERVICE MODE..................................................4
• SERVICE ADJUSTMENT ................................... 5
• TROUBLESHOOTING ........................................ 9
• WAVEFORMS ...................................................13
S39E1SX-68JS7
Page
• SOLID STATE DEVICE BASE DIAGRAM ........ 13
• CHASSIS LAYOUT ............................................14
• DESCRIPTION OF SCHEMATIC DIAGRAM.... 15
• SCHEMATIC DIAGRAM ................................... 15
• BLOCK DIAGRAM .............................................26
• PRINTED WIRING BOARD ASSEMBLIES....... 30
• PARTS LIST ......................................................37
COLOUR TELEVISION MODELS SX-68JS7/SX-68JS9SERVICE MANUAL
SX-68JS7
SX-68JS9
MODELS

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SX-68JS7
SX-68JS9
FEATURES SPECIFICATIONS
Specifications are subject to change without notice.
■Auto search tuning system ■AI-OPC function ■100 CH. program memory ■IGR(B/G) stereo sound ■Black stretch circuit ■CATV hyper band ■Digital comb filter ■2 mode spatializer ■Apertual control circuit (Y/C Transient Improver) ■S Terminal. ■6 language OSD ■7-entertainment menufunction ■ON-TIMER/OFF-TIMER combination use ■Picture noise reduction circuit ■Blue back noise mute ■Front AV-IN terminal & Rear AV in/out terminal. ■AST BOX (SX-68JS9 Only)
Convergence........................................................................Self Convergence System Focus ...............................................................Bi-Potential, Uni-Potential Electroslatic Sweep Deflection ............................................................................................Magnetic Intermediate Frequency Picture IF Carrier........................................................................................38.9 MHz Sound IF Carrier ........................................................................................33.4 MHz Colour Sub-Carrier PAL/NTSC .................................................................................................34.47MHz NTSC ........................................................................................................35.32MHz Power Input.............................................................................. AC 220-240V, 50/60Hz Power Consumption.............................................................................................184W Audio Power Output Rating .................................................................10 W x 2 (Max) Speaker Size ................................................6 x 13 cm Elliptic x 2pcs. + 4 cm Round x 2pcs. Voice Coil Impedance .....................................................................7 ohm at 400 Hz Aerial Input Inpedance ...................................................................... 75 ΩUnbalanced Receiving Channels PAL-B/G VHF ..................................................................................................... AU0 thru 12 UHF...................................................................................................AU28 thru 69 Receiving Frequency VHF ........................................................................... 44.25MHz thru 463.25MHz UHF......................................................................... 471.25MHz thru 863.25MHz

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SX-68JS7
SX-68JS9
IMPORTANT SERVICE NOTES
Maintenance and repair of this receiver should be done by quali- fied service personnel only.
SERVICING OF HIGHVOLTAGE SYSTEM AND PICTURE TUBE When servicing the high voltage system, remove static charge from it by con- necting 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 many produce potentially hazardous radiation with prolonged exposure at close range, the following pre- cautions should be observed: 1. When repairing the circuit, be sure not to increase the high voltage to more
than 34.0 kV (at beam 0µA) for the set.
2. To keep the set in a normal operation, be sure to make it function on 30.5 ±
1.5kV (at beam 1.6mA) 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
repairs, never forget to check for such high voltage after the work.
3. Donotsubstitute apicturetubewith unauthorizedtypesand/or brandswhich
may cause excess X-Ray radiation.
BEFORE RETURNINGTHE RECEIVER Before returning the receiver to the user, perform the following safety checks.
1. Inspect all lead dress to make certain that the 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, insulat-
ing fishpapers, cabinet backs, adjustment and compartment covers or shields, isolation resistor- capacity networks, mechanical insulators etc.
ADJUSTMENT PRECAUTIONS
This model’s setting are adjusted in two different ways: though the I2C bus
control and in the conventional analog manner. The adjustments via the I2C bus
control include preset-only items and variable data.
1. Calling the service mode by the microprocessor.
(1) Set the switch S1006 to the service mode position, and the microprocessor is
put service mode. (Adjustment through the I2C bus control)
(2) Press the CH DOWN key on the remote controller to get ready to select the
modes one by one.
(3) Press the CH UP key on the remote controller to get ready to select the modes
in the order opposite to the above step(2). (See SERVICE MODE)
(4) Using the VOLUME ∧/ VOLUME ∨ keys on the remote controller, the data can
be modified.
(5) Set the switch S1006 to the normal mode (OFF) position, and the microproc-
essor is put out of the service mode.
2. Factory Presettings.
(1) Set the switch S1006 to the service mode position and turn on the main power
switch. Initial values are automatically preset only when a new E2PROM is used (judgement with the first 4 bytes).
(2) The initial data are preset as listed in SERVICE MODE. (3) Some settings should be modfied, and the others should remain as preset. For
details, see SERVICE MODE.
Note: Once the chassis has been put together, be sure to set the switch S1006 to
the service mode position first and then turn on the main power switch (See 2- (1) above). Turning on the power without initializing the E2PROM may caouse
a flow of excess beams.

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SX-68JS7
SX-68JS9
SERVICE MODE
(1) Press the specific keys to change the mode as follows.
RASTER mode CUT-OFF mode 50Hz ADJUST mode
50Hz ADJUST mode
60Hz ADJUST mode SUB-ADJUST mode
SUB-ADJUST mode
V-AMP 50Hz
(V-AMP5)
V-LINE 50Hz
(V-LIN5)
S-CORRECT 50Hz
(V-SCOR5)
V-PHASE 50Hz
(V-PHS5)
H-PHASE 50Hz
(H-PHS5)
H-SIZE 50Hz
(V-SIZE5)
H-COMPENSATION
(H-COM)
EW-PARABOLA
(E/W PAR)
V-BIAS
(V-BIAS)
∫
CORRECTION
(V-
∫
COR)
EW-CORNER
(E/W-COR)
TRAPEZIUM
(TRAPE)
V-COMPENSATION
(V-COM)
In the direction of allow: CH DOWN key In the opposite direction: CH UP key
In the direction of allow: CH DOWN key In the opposite direction: CH UP key
In the direction of allow: CH DOWN key In the opposite direction: CH UP key
SUB-CONTRAST (SUB CON)
SUB-BRIGHT (SUB BRI)
SUB-COLOUR (SUB COL)
SUB-TINT (SUB TIN)
SUB-SHARPNESS (SUB SHP)
SUB-VOLUME (SUB VOL)
60Hz ADJUST mode
V-AMP 60Hz (V-AMP6)
V-LINE 60Hz(V-LIN6)
S-CORRECT 60Hz(V-SCOR6)
V-PHASE 60Hz(V-PHS6)
H-PHASE 60Hz(H-PHS6)
H-SIZE 60Hz (V-SIZE6)
In the direction of allow: CH DOWN key In the opposite direction: CH UP key
(00H) 12H (01H) 37H (02H) 87H (03H) 54H R CUT OFF 384 ~ 1023 384 G CUT OFF 384 ~ 1023 384 B CUT OFF 384 ~ 1023 384 G DRIVE 0 ~ 255 127 B DRIVE 0 ~ 255 127 50Hz V-AMP 0 ~ 127 66 0 *1 50Hz V-LINEARITY 0 ~ 31 22 0 *1 50Hz S-CORRECTION 0 ~ 31 15 0 *1 50Hz V-PHASE 0 ~ 7 4 0 *1 50Hz H-PHASE 0 ~ 31 11 +5 *1 50Hz H-SIZE 0 ~ 63 34 -1 *1 60Hz V-AMP 0 ~ 127 66 60Hz V-LINEARITY 0 ~ 31 22 60Hz S-CORRECTION 0 ~ 31 15 60Hz V-PHASE 0 ~ 7 4 60Hz H-PHASE 0 ~ 31 16 60Hz H-SIZE 0 ~ 63 33 EW-PARABOLA 0 ~ 63 40 V-BIAS 0 ~ 7 4 ∫-CORRECTION 0 ~ 15 15 EW-CORNER 0 ~ 15 8 TRAPEZIUM 0 ~ 63 28 V-COMPENSATION 0 ~ 15 4 H-COMPENSATION 0 ~ 15 4 BELL FILTER 0 ~ 7 4 SECAM R-Y 0 ~ 15 6 SECAM B-Y 0 ~ 15 6
CHROMA GATE PULSE
0 ~ 15 0
SUB-CONTRAST 0 ~ 127 127 SUB-BRIGHT 0 ~ 255 127 SUB-COLOUR 0 ~ 115 55 SUB-TINT 0 ~ 127 63 SUB-SHARPNESS 0 ~ 127 63 SUB-VOLUME 43 ~ 53 53
BS DET SRT POINT (LEVEL)
0 ~ 15 3
8MHz f RESPONCE(RS)
0 ~ 7 0
SRTTRACKING (RTC) 0 ~ 7 4 V/C/J BS (BS) 0 ~ 1 0
E2PROM item Data adjustable range Data initial value Remarks
To go to the service mode, the data at the E2PROM's addresses 00H thru 03H are read. If the data ae no as given below, the E2PROM is initialized according to the table below.
Address: Data
00H: 12H 02H: 87H 01H: 37H 03H: 54H

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SX-68JS9
Key input Mode
(6) If key in the remote control key as kelow, it will directly switch to the mode coneerned.
TEXT/MIX BELL FILTER INDEX GATE PILSE SIZE SUB BRIGHT TIMED PAGE SUB COLOUR HOLD SUB TINT REVEAL LEVEL YELLOW SUB VOLUME CYAN (FLOF 4) SUB CUNTRAST RED (FLOF 1) H-POSITION GREEN (FLOF 2) V-POSITION STORE
SUB H-PULSE DELAY 50Hz
FLOF/LIST
SUB H-PULSE DELAY 60 Hz
User data
CONTRAST 60 COLOUR 0 BRIGHTNESS 0 TINT 0 SHARPNESS 0 S-VOL 0 TREBLE 0 BASS 0 WHITE TEMP 0 BALANCE 0 SPATIALIZER OFF AI-OPC OFF BLUE BACK OFF C SYSTEM AUTO PICTURE NR OFF
(4) While changing mode, EEPROM will memorize the service data. (5) In the service mode, the user data are preset as follows.
SERVICE ADJUSTMENT
PIF/AFT/AGC ADJUSTMENT
1. Get the tuner ready to receive the E-9CH
signal,butwithnosignalinput.Adjust PLL data.
2. Connect the sweep generator's output cable
to the tuner antenna. (RF sweep)
3. Adjust the sweep generator's output level to
80dBµV.
4. Connect the responce lead (use a low-imped-
ance probe with wave detector;see
Fig.1
.) to
the tuner's IF output terminal. (Thisterminal must havethe probealonecon- nected.)
5. Set the RF AGC voltage to 0-6V with no con-
tact with waveform.
6. Adjust the tuner IF coil to obtain the waveform
as shown in
Fig.2
.
Note: Be sure to keep the tuner cover in position
during this adjustment.
1. TUNER IFT (preset) ADJUSTMENT:TU201(preset)
1000p
1000p
10kΩ
75Ω100kΩOscilloscope
IF-OUT
E9CH
- 1.5dB±0.8dB
PC
* Turn the core counterclockwise for the
UP direction, and clockwise for the DOWN direction. Adjust the T201 core to point B (between B' and B''). Point A and C are rejectable.
DC voltage at TP201
6V
3.3V
DOWN A B' B B'' C UP
2. COIL ADJUSTMENT:T201 (VCO)
1. Receive the E-12ch (PAL colour bar) signal.
Ifthis signal isnotavailable,anysignalabove the E-5CH band is acceptable. • Field strength: 55-80 dBµV Make sure the frequecy is almost the same as that of the received channel (±30 kHz).
2. Using the channel setting control, make a
frequency of 224.25 MHz appear on the screen. (AFT off) (If any other channel than E-12CH is received, make its frequency on the screen.)
3. Adjust T201 so that the DC voltage at the
SFT OUT terminal (TP201) be 4.5 ±0.1V.
4. TurnT201 clockwise to have a 8V point and
counterclockwiseto 0.2V thenadjustthe coil position in the middle of the above range.
E2PROM item Data adjustable range Data initial value Remarks
NICAM ERROR AUTO (N-AMDIS)
0 ~ 1 0
V-ENHANCEMENTLEVEL (V-ENH)
0 ~ 7 4
COLOUR BANDPASS FILTER (CBPF)
0 ~ 1 0
1 LINE DOT IMPROVEMENT (LD)
0 ~ 1 0
CORING 0 ~ 1 0
*1: While 50Hz. Mode has been adjusted, 60Hz. Mode's data automatically will be input.
(But while 60Hz mode has been adjusted, 50Hz mode's data won't be updataed.)

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SX-68JS7
SX-68JS9
3. RF AGC CUT-IN ADJUSTMENT: R259 SOUND ADJUSTMENT
1. RF SUB-SOUND ADJUSTMENT: R256
1. Receive the "PAL COLOUR BAR" signal.
• Signal: 400 Hz, 100% modulation
2. Connect the oscilloscope to the Audio Our (L or R) terminal. (Terminate with a 10 kohm
impedance.)
3. Adjust R256 so that the 400 Hz sine wave be of 1.76Vp-p.
• Adjustment error: 1.76 ±0.04/-0.06 Vp-p
1. Receive the "PAL COLOUR BAR" signal.
• Field strength:57 ±1 dBµV (75 ohms open)
2. Connect the oscilloscope to P201, as shown
in
Fig. 4.
• Bias box:About 6.5V
3. Turn R259 to have the highest voltage. 4. Turn R259 slowly in the oppsite direction untill
the voltage goes down 0.1V below the highest level.
5. Adjust the signal level to 63-67 dBµV and make
sure there are no noise.
6. Now adjust the signal level to 90-95 dBµV and
make sure there is no chrominance modulation beat.
Note: If a 50 ohm field strength meter is used with-
out a 50/75 impedance converter,set the field strength to 55 ±1 dBµV. Pay attention to a
loss that would be cause with the converter.
4. VIDEO DETECTION LEVEL ADJUSTMENT: R235
1. Receive the "B/G SYSTEM PAL COLOUR BAR" signal (100% white colour bar). 2. Adjust R235 so that the video output at the AV OUT terminal be 1.0 ±0.05 Vp-p with a 75-
ohm termination.
Oscilloscope TV Set
0.1V
Bias box
P201
SYNC DETECTION ADJUSTMENT
1. Put the unit in the A/V mode with no signal input. 2. Connect the frequency counter to TP1680 (on the MAIN unit PWB).
(Use a probe with small input capacitance: 10:1 or so of the oscilloscope)
3. Adjust R1685 so that the frequency counter should read 15.65 ±0.05 kHz.
• Warm up the unit for 20 minutes or longer before starting this adjustment.
1. SYNC DETECTION FREQUENCY ADJUSTMENT: R1685
DIGITAL COMB FILTERY LEVEL ADJUSTMENT
1. DIGITAL COMB FILTERY LEVEL ADJUSTMENT: R5467
1. Receive the PAL colour bar (100% white colour bar) signal. (1.0 Vp-p) 2. Connect the oscilloscope to TP5462 (emitter of Q5467). 3. Adjust R5467 so that the Y signal (100% white) at TP5462 be 2.0 Vp-p ±0.1 Vp-
p.
Note: Make sure that the signal is linearly amplified overall. (The 100% portion
should be kept intact.)
2. SUB-SOUND ADJUSTMENT (bus adjustment)
1. Receive the "PAL COLOUR BAR" signal.
• Signal: 400 Hz, 100% modulation (50 kHz dev.)
2. Turn up the volume control to maximum. 3. Connect the VTVM's probes to the SI connector (pin (1): L-ch, pin(2): Ground, pin (3): R-
ch).
4. Adjust the sub-sound data so that the VTVM should8.35Vrms (for the left channel).
• Adjustment error: 8.35 ±0.1 Vrms
Notes:
• Spatializer off • In the S-Normal mode • S-VOL control at MAX position • Speaker impedance: 7Ω
3. NOISE MUTE CHECKING
1. Receive the "PAL COLOUR BAR" signal. 2. Turn up the volume control to maximum and make sure the sound is heard from the
speakers.Then put the unit in the no-signal state.
3. Be sure that the sound mute is effective. 4. Finally turn down the volume control minimum.
1. Receive the green only signal or "MONOSCOPE
PATTEN" signal.Adjustthe contrast control tohave a beam current of 1.1 mA.
2. Degaussthe CRTenough with thedegaussingcoil. 3. Keep the purity magnet in the zero magnetic field
in advance. Roughly adjust the convergence.
4. Observe the point "a" and "b", as shown in
FIG. A
,
through a microscope. Adjust the landing to the rank "A" requirements.
5. Adjust the raster rotation to 0 eastward. 6. Tighten up the deflection coil screws.
•Tightening torque: 108 N ±20 N
(11 ±2 kgf)
7. While observing the CRT screen corners, apply the
magnet sheet to have the landing at rank "C".
Note: Before starting this adjustment, warm up the
unit for 30 minutes or longer at a beam current of over 1300 µA.
PURITY ADJUSTMENT
A
B
A = B
A
B
ab
Fig. A
Rank "A" (on the left of the CRT)
Rank "A" (on the right of the CRT)

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SX-68JS7
SX-68JS9
(To be done after the purity adjustment)
CONVERGENCE ADJUSTMENT
1. Receivethe "CROSSHATCHPATTERN" signal. 2. Using the remote controller, call the Normal
mode.
STATIC CONVERGENCE 1. Turn the 4-pole magnet to a proper opening
angle in order to superimpose the blue and red colours.
2. Turn the 6-pole magnet to a proper opening
angle in order to superimpose the green colour over the blue and red ones.
DYNAMIC CONVERGENCE 1. Adjust the convergence on the fringes of the
screen in the following steps. a) Fig.a:Drivethewedge atpoint"a" andswing
the deflection coil upward.
b) Fig.b:D
rive the wedge at points "b" and "c" and
swing the deflection coil down ward.
c) Fig. c: Drive the"c"wedgedeeperand swing
the deflection coil rightward.
d) Fig. d: Drivethe "b"wedgedeeper andswing the deflection coil leftward.
2. Fix all the wedges on the CRT and apply glass
tape over them.
3. Apply lacquer to the deflection yoke lock screw,
magnetunit (purity, 4-poleand6-pole magnets) and magnet unit lock screw.
B G R
B G R
R G B
R G B
Fig. a Fig. b
Fig. c Fig. d
B
G
R
B
G
R
R
G
B
R
G
B
Wedge "a"
Wedge "b" Wedge "c"
About 100°
About 100°
Lacquer
4-pole magnet
6-pole magnet
4 - pole magnet
CRT neck
Lacquer
CRT CUT-OFF, BACKGROUND AND SUB-CONTRAST ADJUSTMENT
1. CRT CUT-OFF ADJUSTMENTS
Adjusting Point
Sub-Brightness: R890
1 Receive "MONOSCOPE PATTERN" signal. 2. Using the remote controller, call up the P-NORM mode. 3. Turn on the service switch and select the cut-off/back-
ground mode.
4. Connect the oscilloscope to TP852 (RED cathode). 5. Set the screen control to 0/10 position. 6. Press the "9" key on the remote controller to reach the
horizontal centering mode.
7. Adjustthe sub-brightnesscontrol (R890) sothattheblank-
ing pulse on the oscilloscope screen be 10 ±1Vp-p.
8. Disconnect the oscilloscope from TP852.
2. WHITE BALANCE and BACKGROUND I2C BUS ADJUSTMENT
9. Turn the screen control clockwise until the horizontal raster of the first glimmering colour
becomes slightly visible.
10. Adjust the cut-off data of the other two colours until the horizontal raster becomes whitish. Note:The data can be turned up and down with the above keys.
• R CUT OFF UP "1" key • G CUT OFF DOWN "5" key • R CUT OFF DOWN "4" key • B CUT OFF UP "3" key • G CUT OFF UP "2" key • B CUT OFF DOWN "6" key
11. Turn the screen control counterclockwise until the horizontal raster disappears.
Note:
Before starting this adjustment, warm up the unit for 30 minutes or longer at a beam
current of 1300
µ
A.
12. Press the "9" key on the remote controller to call the normal mode. 13.
Using the remote controller, call the sub-brightness setting mode.(Receive the E-2CH signal).
14. Set the sub-brightness data so that the second black portion of the window pattern looks
sinking.The service mode adjustment in the above steps (13) and (14) should be carried out after the white balance and background adjustments.
Note: Make sure the sub-brightness data is smaller than 129 (initial value 127). If above
130,go back to Step(7).Readjust the sub-brightness control(R890) so that the blank- ing pulse level on the oscilloscope screen be within +0.5Vp-p from the first-adjusted level. Now take Step(8) and the following over again. (The sub-brightness data is adjusted to about 20 steps lower.) • If the sub-brightness data is above 130,there will be problem with the user's bright- ness control.
1. Receive the "MONOSCOPE PATTERN" signal. 2. Using the remote controller, call the Video Normal mode. 3. Connect the beam ammeter betweenTP601 and TP602. 4. Roughly adjust R1631 (sub-contrast control) to have a beam current of about 1.6 mA. 5. Adjust the G-drive and B-drive data to have a colour temperature of 12300ºK (white).
•12300K°X: 0.272
Y: 0.275
(with a Minolta colour temperture meter) Note:The data can be turned up and down with the above keys.
• G-DRIVE UP "7" key • B-DRIVE UP "8" key • G-DRIVE DOWN " " key • B-DRIVE DOWN "0" key
6. Adjust the contrast and brightness controls to have a beam current of 200 µA. Now check
the background clour. If the colour temperature is not 12300ºK, go back to No. 1 on the preceding page.
Note:Before starting this adjustment,warm up the unit for 30 minutes or longer at a beam
current of 1300µA.
10 ±1Vp-p

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SX-68JS9
CRT CUT-OFF, BACKGROUND AND SUB-CONTRAST ADJUSTMENT (Continued)
3. SUB-CONTRAST ADJUSTMENTS
Adjusting Point
Sub-Contrast: R631
1. Receive the "MONOSCOPE PATTERN" signal. 2. Using the remote controller, call the Video Normal mode. 3. Connect the beam ammeter betweenTP601 and TP602. • Ammeter's full scale: 3mA range • Ammeter's positive (+) read: TP602 • Ammeter's negative (-) read: TP601 4. Adjust R1009 (sub-contrast control) so that the beam current be 1.6 mA.
Note: Before starting this adjustment, warm up the unit for 30 minutes or longer at a beam
current of 1300µA.
HORIZONTAL AND VERTICAL CIRCUIT ADJUSTMENT
1. SERVICE MODE DATA ADJUSTMENT
For this items 1 thru 6 below, use the remote controller in the service mode.
1. V-AMPLITUDE 50: Adjust the overscan 8.5% (E-5). 2. V-LINEARITY 50: Adjust to get the best linearity. 3. V-S-CORRECTION 50: Preset (readjust if the linearity is poor). 4. V-PHASE 50 (V-CENTER): Align the screen center with CRT's geometrical center (E-
5)
5. H-PHASE 50 (H-CENTER): Align the screen center with CRT's geometrical center (E-
5)
6. H-SIZE 50: Adjust the overscan 8.5% (E-5). 7. EW-PALABOLA (SIDE-PIN): Adjust so that the second vertical lines from the left and
right ends of the crosshatch pattern be straight (E-2).
8. V-BIAS: Preset 9. V-S-CORRECTION: Preset 10. EW-CORNER (SUB-SIDEPIN): Preset (readjust if the picture quality at the corners is de
graded.)
11. TRAPEZIUM: Preset (Readjust ifnthe trapezium is poor).(25) 12. V-COMPENSATION: Preset 13. H-COMPENSATION: Preset 14. Others: FortheV-HEIGHT 60,V-LINEARITY60,V-S-CORRECTION
60,V-SHIFT 60,H-SHIFT60, andH-WIDTH 60 adjustment, theircorrected dataareautomatically enteredwhenthe cor- responding 50 Hz mode adjustments are made.
2. FOCUS ADJUSTMENT
1. Receive the "MONOSCOPE PATTERN" signal. 2. Using the rmote controller, call theVideo Normal mode. 3. Adjust the focus control so that the center of screen is good focus.
PAL CHROMA ADJUSTMENT
1. SUB-COLOUR ADJUSTMENT (I2C bus adjustment, main picture)
1. Receive "PAL colour bar" signal. 2. Using the remote controller, call the Video Nor-
mal mode.
3. Connect the oscilloscope to TP852 (RED cath-
ode). (Use a 10:1 probe.) •Range: 2V/div. •Sweep time: 20µsec/div.
4. Using the remote controller, call the sub-colour
adjustment mode.Adjust the sub-colour data so that the 75% white and red portions of the PAL colour bar be at the same level. See
Fig.6.
5. Clear the adjustment mode. (Now the 100%
white and red portions will be at the same level.)
Fig. 5.
Fig. 6.
NTSC CHROMA ADJUSTMENT
1. SUB-TINT ADJUSTMENT (main picture, I2C bus adjustment, inset picture)
1. Callthe sub-tintadjustmentmode.RceivetheJA-
8CH "NTSC COLOUR BAR" signal.
2. Connect the oscilloscope to TP806 (B-Y)
•Range: 20mV/div.(AC) •Sweep time: 20µsec/div. (Use a 10:1 probe.)
3. Adjust the sub-tint data to obtain the waveform
as shown in
Fig.10
.
4. Clear the adjustment mode. Note:TP806......IC801 55pin
Fig.7.

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SX-68JS9
A/V INPUT AND OUTPUT CHECK
1. AUDIO/VIDEO OUTPUT CHECK
1. Receive the E-12CH "PAL COLOUR BAR" signal (100% white colour 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 10k-ohm impedance.Make sure the output is as specified
(1.76Vp-p ±3dB).
2. AUDIO/VIDEO INPUT CHECK, S-TERMINAL INPUT CHECK
1. UsingtheTV/AV keyon the remotecontroller, make sure thatthe modeschange in orderofTV,
AV1, AV2, AV3 andTV again and that the video and audio outputs are according to the input and output terminals for each mode.
2. In the AV1 mode, connect the connector to the S-VIDEO input terminal. Make sure the AV
modechanges tothe S-VIDEOmode,thatthe unitfunctions well, and that"AV1-S" appearson the screen.
3. AV3 AUTOMATIC ID CHECKING
1. Using the remote controller, receive a TV broadcast signal. 2. Feed the signal to the AV3 VIDEO input terminal. Make sure the AV3 mode shows up auto-
matically.
*Setting:AUTO SELECT to be turn on.
PROTECTOR PERFORMANCE CHECK
1. BEAM PROTECTOR
1. Receive the E-5CH "MONOSCOPE PATTERN" signal. 2. Set the contrast control to maximmum. 3. Set the brightness control to maximum. 4. Make a short-circuit between the collector and emitter of Q853 and make sure that the protec-
tor is activated and the stand-by mode is called.
2. HIGH-VOLTAGE PROTECTOR
1. Receive the E-5CH "MONOSCOPE PATTERN" signal. 2. Connect the bias box to the cathode (R1625 side) of D1607. 3. Adjust the bias box voltage to 16V and make sure that the protector is not activated.
•Reference: usually about 19V
4. Boost the bias box voltage to 24V and make sure that the protector is activated.
3. OTHER PROTECTORS
1. In checking the performance of other protectors – for example, the one against shorting of
smoothing electolytic capacitor of + B line –, pay attention not to damage or deteriorate ele- ment.
TROUBLESHOOTING
Check the voltage at pin (6) of IC501 and pin (3) of IC502.
NO VERTICAL SCAN
Circuits to be checked: • IC501, 502 and its
adjacent circuit
Check IC501, IC502 and related circuits
Normal Abnormal
Normal
Check IC801 and its peripheral parts.
Check vertical trigger purse at pin (64) of IC801. Check L1501, D1605, D1506
and R1650.
Abnormal
Note1: Make sure that the switch S1006 is at the position for
the service mode, not for the horizontal centering mode. (At the center or farthest position, the switch is for the normal mode.) The "9" key on the remote controller is used to turn on and off these modes.
Note2: The vertical sync signal must be fed to pin (62) of
IC1001 in oder not to activate the vertical no-scan protector. Take this measure with the protector circuit for the troubleshooting on the following pages.

10
SX-68JS7
SX-68JS9
Circuits to be checked: • Power circuit. • Protector circuit • Peripheral circuit of
Bus Line.
Check the peripheral circuit of Q751, IC1004.
Check the power circuit consisting of T701 etc.
Normal
Check F701.
Replace the Fuse.
Is the Fuse again blown out?
Does 5V appear at pin (64) of IC1001?
Blown out
A
No
No Yes
Yes
Check IC1001, Q1017 and Q750.
B
E
2
PROM
(IC1002)
AV-SW (IC5451)
VCJ1 (IC801) RGB (IC804) PDC (IC4102) S-CONTROL (IC303)
Lights up turn off
2 sec 1 sec
Other pattern: Other I
2
C bus control IC or unit.
(It has SDA and SCL PORT.)
Does D1058 (POWER LED) turn on?
Does horizontal circuit momentary oscillate?
D1058 (POWER LED) turns on and off. Clear the bus error by +5 voltage pin (42)[CONNECT GND] of IC1001 first and then turning on the power. (D1058 is then supposed to stop flashing).
NO RASTER
Circuits to be checked: • Power circuit. • Protector cirucit. • Peripheral circuit of
Bias Line.
Normal
Check CRT connector (KY), (H) bias.
Does RY701 turn on?
Turns on, but soon turns off.
Abnormal
Check Q850, Q851, Q852, Q853, Q854, Q855.
Check protector circuit and its related parts.
Check the power circuit consisting of IC701, IC702, IC704, D701, D707, D711, Q701 etc.
Yes
Yes (RED)
Yes
(Bus error)
No
Check protector.
Put pin (42) of IC1001 in the original state and see many often D1058 flashes in red. This indicates which IC to check up.
Yes No
No
A
B
Check IC801, IC804, D807, D808, D809.