SHARP 36US650 Service Manual

36US650

SERVICE MANUAL

COLOR TELEVISION

Chassis No. GB-1

MODELS

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.

36US650

CONTENTS

Page

» ELECTRICAL SPECIFICATIONS .........................................................................................................1

» IMPORTANT SERVICE SAFETY PRECAUTION .................................................................................2

» LOCATION OF USER'S CONTROL .....................................................................................................4

» INSTALLATION AND SERVICE INSTRUCTIONS ................................................................................5

» SERVICE ADJUSTMENT ....................................................................................................................9

» CHASSIS LAYOUT .............................................................................................................................12

» SCHEMATIC DIAGRAMS ...................................................................................................................14

» PRINTED WIRING BOARD ASSEMBLIES ........................................................................................24

» REPLACEMENT PARTS LIST ............................................................................................................28

» PACKING OF THE SET ......................................................................................................................39

ELECTRICAL SPECIFICATIONS

POWER INPUT..................................................... 120V AC 60 Hz

POWER RATING .................................................................. 167W

PICTURE SIZE ........................................... 3,905cm2 (605sq inch)

CONVERGENCE ............................................................. Magnetic

SWEEP DEFLECTION .................................................... Magnetic

FOCUS ............................................... Hi-Bi-Potential Electrostatic

INTERMEDIATE FREQUENCIES

Picture IF Carrier Frequency..................................... 45.75 MHz

Sound IF Carrier Frequency...................................... 41.25 MHz

Color Sub-Carrier Frequency .................................... 42.17 MHz

(Nominal)

AUDIO POWER

OUTPUT RATING ..............3.0W + 3.0W (at 10% distortion and

Dual CH Operate)

SPEAKER

SIZE ........................................................12 x 6 cm oval (2 pcs.)

VOICE COIL IMPEDANCE............................... 8 ohm at 400 Hz

ANTENNA INPUT IMPEDANCE

VHF/UHF.....................................................75 ohm Unbalanced

TUNING RANGES

VHF-Channels...............................................................2 thru 13

UHF-Channels ............................................................14 thru 69

CATV Channels ...........................................................1 thru 125

(EIA, Channel Plan U.S.A.)

Specifications are subject to change without prior notice.

SHARP CORPORATION

This document has been published to be used for after sales service only. The contents are subject to change without notice.

36US650

IMPORTANT SERVICE SAFETY PRECAUTION

Service work should be performed only b y qualified service technicians who are thoroughly familiar with all safety checks and the servicing guidelines which follow:

WARNING

1. For continued safety, no modification of any circuit should be attempted.

2. Disconnect AC power before servicing.

3. Semiconductor heat sinks are potential shock hazards when the chassis is operating.

4. The chassis in this receiver has two ground systems which are separated by insulating material. The nonisolated (hot) ground system is for the B+ voltage regulator circuit. The isolated ground system is for the low B+ DC voltages and the secondary circuit of the high voltage transformer. To prevent electrical shock use an isolation transformer between the line cord and power receptacle, when servicing this chassis.

CAUTION: FOR CONTINUED PROTECTION AGAINST A RISK OF FIRE, REPLACE

4A 125V

ONLY WITH SAME TYPE 4A125V FUSE.

SERVICING OF HIGH VOLTAGE SYSTEM AND PICTURE TUBE

When servicing the high voltage system, remove the static charge by connecting a 10k ohm resistor in series with an insulated wire (such as a test probe) between the picture tube ground and the 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 anode completely.

X-RADIATION AND HIGH VOLTAGE LIMITS

1. Be sure all service personnel are aware of the procedures and instructions covering X-radiation. The only potential source of X-ray in current solid state TV receivers is the picture tube. However , the picture tube does not emit measurable X-Ray radiation, if the high voltage is as specified in the "High Voltage Check" instructions. It is only when high voltage is excessive that Xradiation is capable of penetrating the shell of the picture tube including the lead in the glass material. The important precaution is to keep the high voltage below the maximum level specified.

2. It is essential that servicemen have available at all times an accurate high voltage meter. The calibration of this meter should be checked periodically.

3. High voltage should always be kept at the rated v alue

−no higher. Operation at higher voltages may cause a failure of the picture tube or high voltage circuitry and;also, under certain conditions, may produce radiation in exceeding of desirable levels.

4. When the high voltage regulator is operating properly there is no possibility of an X-radiation problem. Every time a color chassis is serviced, the brightness should be tested while monitoring the high voltage with a meter to be certain that the high voltage does not exceed the specified value and that it is regulating correctly.

5. Do not use a picture tube other than that specified or make unrecommended circuit modifications to the high voltage circuitry.

6. When trouble shooting and taking test measurements on a receiver with excessiv e high voltage , av oid being unnecessarily close to the receiver. Do not operate the receiver longer than is necessary to locate the cause of excessive voltage.

IMPORTANT SERVICE SAFETY PRECAUTION

2 2

(Continued)

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BEFORE RETURNING THE RECEIVER (Fire & Shock Hazard)

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 materials, cabinet backs, adjustment and compartment covers or shields, isolation resistor-capacity networks, mechanical insulators, etc.

3. To be sure that no shock hazard exists, check for leakage current in the following manner.

• Plug the AC cord directly into a 120 volt AC outlet, (Do not use an isolation transformer for this test).

• Using two clip leads, connect a 1.5k ohm, 10 watt resistor paralleled by a 0.15µF capacitor in series with all exposed metal cabinet parts and a known earth ground, such as electrical conduit or electrical ground connected to earth ground.

• Use an AC voltmeter having with 5000 ohm per volt, or higher, sensitivity to measure the A C voltage drop across the resistor.

• Connect the resistor connection to all exposed metal parts having a return to the chassis (antenna, metal cabinet, screw heads, knobs and control shafts, escutcheon, etc.) and measure the AC voltage drop across the resistor. AII checks must be repeated with the AC line cord plug connection reversed. (If necessary, a nonpolarized adapter plug must be used only for the purpose of completing these check.) Any current measured must not exceed 0.5 milliamp. Any measurements not within the limits outlined above indicate of a potential shock hazard and corrective action must be taken before returning the instrument to the customer.

1.5k ohm 10W

0.15µF

TEST PROBE

TO EXPOSED

TAL PARTS

234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121

CONNECT TO KNOWN EARTH GROUND

SAFETY NOTICE

Many electrical and mechanical parts in television receivers have special safety-related characteristics. These characteristics are often not evident from visual inspection, nor can protection afforded by them be necessarily increased by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in this manual; electrical components having such features are identified b y "å" and shaded areas in the Replacement Parts Lists and Schematic Diagrams.

234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121

For continued protection, replacement parts must be identical to those used in the original circuit. The use of substitute replacement parts which do not have the same safety characteristics as the factory recommended replacement parts shown in this service manual, may create shock, fire, X-radiation or other hazards.

LOCATION OF USER'S CONTROL

Front Panel

POWER

Press On.

Press again Off.

SENSOR AREA FOR REMOTE CONTROL

Press Accesses MAIN MENU. Press again Exits MAIN MENU.

Basic Remote Control Functions

POWER

Press → On. Press again → Off.

REMOTE KEYPAD

Accesses any channel from keypad.

FLASHBACK

Returns to previous channel.

PERSONAL PREFERENCE

With the Personal Pref erence buttons, you can program your favorite programs by using the 4 categories A, B, C and D. The channels can be accessed quickly by using these buttons.

VOLUME UP/DOWN

(+) Increases sound. (–) Decreases sound.

• In menu mode, changes or selects the TV adjustments.

Press → Accesses MAIN MENU. Press again → Exits MAIN MENU.

CATV/DVD-TV/VCR MODE SELECT SWITCH

In TV/VCR position, sends power and channel select commands (Channel up/down and Random Access buttons) to the TV and VCR control. In CATV/DVD position, sends power and channel select commands to a cable TV converter and DVD control.

DVD/VCR CONTROL

POWER

DVD VCR

DISPLAY

FLASHBACK

PERSONAL PREFERENCE

VOL

—

REW PLAY

PAUSE

STOP

REC

PIP

SWAP

FREEZE

MOVE

TV • CATV • VCR • DVD

VOLUME UP/DOWN

(+) Increases sound. (–) Decreases sound.

INPUT

ENTER

100

VOL

MUTE

CATV TV

DVD VCR

CH/SKIP

SELECT

VIDEO L-AUDIO-R

IN 2

(INSIDE DOOR)

CHANNEL UP/DOWN (

) Selects next higher

channel.

( ) Selects next lower

channel.

• Press both at the same

time to access the MAIN MENU screen.

Infrared T ransmitter Windo w

DISPLAY

Press → Displa ys receiving channel for four seconds. Press again → Removes display.

• Temporarily displays receiving channel when in Closed Caption mode.

INPUT

Press → Switch to external video INPUT 1 mode. Press 2 times → Switch to external video INPUT 2 mode. Press 3 times → Switch to external video INPUT 3 mode or COMPONENT mode. Press 4 times → Switch back to the original TV mode.

ENTER

Used in some instances where a Cable Converter Box requires an “enter” command after selecting channels, when using the REMOTE KEYPAD button.

CHANNEL UP/DOWN

(') Selects next higher channel. (") Selects next lower channel.

•

Moves the “

” mark of the MENU

screens.

MUTE

Press → Mutes sound. Press again → Restores sound.

• CLOSED CAPTION appears when sound is muted.

PIP FUNCTION

With the VIDEO inputs, y ou can w atch two pictures at the same time.

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Note:

• The above shaded buttons on the Remote Control glow in the dark. To use the glow-in-the-dark display on the remote control, place it under a fluorescent light or other lighting.

• The phosphorescent material contains no radioactive or toxic material, so it is safe to use.

• The degree of illumination will vary depending on the strength of lighting used.

• The degree of illumination will decrease with time and depending on the temperature.

• The time needed to charge the phosphorescent display will vary depending on the surrounding lighting.

• Sunlight and fluorescent lighting are the most effective when charging the display.

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INSTALLATION AND SERVICE INSTRUCTIONS

Note: (1)When performing any adjustments to resistor controls and transformers use non-metallic

screwdrivers or TV alignment tools.

(2)Before performing adjustments, the TV set must be on at least 15 minutes.

CIRCUIT PROTECTION

The receiver is protected by a 4.0A fuse (F701), mounted on PWB-A, wired into one side of the AC line input.

X-RADIATION PROTECT OR CIRCUIT TEST

After service has been performed on the horizontal deflection system, high voltage system, B+ system, test the X-Radiation protection circuit to ascertain proper operation as follows:

1. Apply 120V AC using a variac transformer for accurate input voltage.

2. Allow for warm up and adjust all customer controls for normal picture and sound.

3. Receive a good local channel.

4. Connect a digital voltmeter to TP651 and mak e sure that the voltmeter reads 13.2 ±0.7V.

5. Apply external 16.3V DC at TP651 by using an external DC supply, TV must be shut off.

6. To reset the protector, unplug the AC cord and plug the AC cord power on. Now make sure that normal picture appears on the screen.

7. If the operation of the horizontal oscillator does not stop in step 5, the circuit must be repaired before the set is returned to the customer.

HIGH VOLT A GE CHECK

High voltage is not adjustable b ut must be checked to verify that the receiver is operating within safe and efficient design limitations as specified checks should be as follows:

1. Connect an accurate high voltage meter between ground and anode of picture tube.

2. Operate receiver for at least 15 minutes at 120V AC line voltage, with a strong air signal or a properly tuned in test signal.

3. Enter the service mode and select the service adjustment "V18" and Bus data "01" (Y-mute on, CRT Cut Off).

4. The voltage should be approximately 33.0kV (at zero beam). If a correct reading cannot be obtained, check circuitry for malfunctioning components. After the v oltage test, make Y-mute off to the normal mode.

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For adjustments of this model, the bus data is converted to various analog signals by the D/A converter circuit.

Note: There are still a few analog adjustments in this series such as focus and master screen voltage.

Follow the steps below whenever the service adjustment is required. See "Table-B" to determine, if service adjustments are required.

1. Service mode

Before putting unit into the service mode, check that customer adjustments are in the normal mode. Use the reset function in the video adjustment menu to ensure customer controls are in their proper (reset) position.

2. Service number selection

Once in the service mode, press the Ch-up or Chdown button on the remote controller or at the set. The service adjustment number will vary in increments of one, from "V01" to "P08". Select the item you wish to adjust.

3. Data number selection

Press the Vol-up or V ol-do wn button to adjust the data number.

DATA NUMBER

SERVICE ADJUSTMENT NUMBER

To enter the ser vice mode and exit service mode.

To enter the service mode manually just press and hold the Vol-down and Ch-up buttons at the same time, plug the AC cord into a wall socket. Now the TV set is switched on and enters the service mode. To exit the service mode, turn the television off by pressing the power button.

CHANNEL

V01

Figure A.

55(085)

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SERVICE

NUMBER

V01 PICTURE 03 0-15(00h-0Fh) V02 TINT 3E 0-127(00h-7Fh) V03 COLOR 2D 0-127(00h-7Fh) V04 SUB-COLOR 10 0-31(00h-1Fh) Must be set to "10" V05 BRIGHT 4D 0-127(00h-7Fh) V06 R CUT-OFF 40 64-255(40h-FFh) V07 G CUT-OFF 40 64-255(40h-FFh) V08 B CUT-OFF 40 64-255(40h-FFh) V09 G DRIVE 40 0-127(00h-7Fh) V10 B DRIVE 40 0-127(00h-7Fh) V11 SHARP 14 0-63(00h-3Fh) Must be set to "1E" V12 N PHASE 01 0-3(00h-03h) Must be set to "01" V13 DC RESTORATION 00 0-3(00h-03h) Must be set to "03" V14 BLACK STRETCH 03 0-3(00h-03h) Must be set to "03" V15 ABL START POINT 03 0-3(00h-03h) Must be set to "03" V16 ABL GAIN 02 0-3(00h-03h) Must be set to "02" V17 Y.POINT 00 0-3(00h-03h) Must be set to "02" V18 Y-MUTE/V-STOP 00 0-2 "00"=Normal, "01"=No-Y, "02"=No-Y & No-Vertical V19 ENERGY SAVE 28 0-63(00h-3Fh) Must be set to "28" V24 LOW-G F7 0-255(00h-FFh) Must be set to "F7" V25 LOW-B E8 0-255(00h-FFh) Must be set to "E8" V26 ML-G 00 0-255(00h-FFh) Must be set to "00" V27 ML-B F9 0-255(00h-FFh) Must be set to "F9" V28 HIGH-G 03 0-255(00h-FFh) Must be set to "03" V29 HIGH-B 06 0-255(00h-FFh) Must be set to "06" V30 WPS 01 0-1 Must be set to "01" V31 RGB CONTRAST 20 0-63(00h-3Fh) Must be set to "2A" V32 Y-DL 02 0-7(00h-07h) Must be set to "02" V33 Y-DL-INPUT 01 0-7(00h-07h) Must be set to "01" V34 VSM GAIN 07 0-7(00h-07h) Must be set to "07" V35 N COMB 01 0-1 Must be set to "01" V36 BPF/TOF-INPUT 00 0-1 Must be set to "01" V37 CORING 00 0-1 Must be set to "00" V38 VSM PHASE 00 0-1 Must be set to "00" V39 COLOR γ 00 0-1 Must be set to "01" V40 SHARP-INPUT 14 0-63(00h-3Fh) Must be set to "1E" V41 TINT-INPUT 3E 0-127(00h-7Fh) V42 PICTURE-COMPONENT 03 0-15(00h-0Fh) V43 TINT-COMPONENT 10 0-31(00h-1Fh) Must be set to "10" V44 COLOR-COMPONENT 30 0-127(00h-7Fh) Must be set to "44" V45 BRIGHT-COMPONENT 4A 0-127(00h-7Fh) V46 R CUT OFF-COMPONENT 40 64-255(40h-FFh) V47 G CUT OFF-COMPONENT 40 64-255(40h-FFh) V48 B CUT OFF-COMPONENT 40 64-255(40h-FFh) V49 G DRIVE-COMPONENT 40 0-127(00h-7Fh) V50 B DRIVR-COMPONENT 40 0-127(00h-7Fh) V51 SHARP COMPONENT 14 0-63(00h-3Fh) Must be set to "1E" V52 N PHASE-COMPONENT 01 0-3(00h-03h) Must be set to "01" V53 C-TRAP 00 0-1 Must be set to "00"

ADJUSTMENT ITEM

INITIAL V ALUE

DA TA

ADJUSTMENT CONTENTS

RANGE

R01 RF-AGC 24 0-63(00h-3Fh) R02 PIF VCO coil – R03 RF-AGC REF 5C 0-255(00h-FFh) Must be set to "5C"

D01 V POSITION 00 0-7(00h-07h) D02 H POSITION 10 0-31(00h-1Fh) D03 V SIZE 12 0-63(00h-3Fh) D04 H SIZE 1F 0-63(00h-3Fh) Must be set to "1E" D05 V-LINEARITY 07 0-15(00h-0Fh)

D06 V-S CORRECTION 08 0-15(00h-0Fh) Must be set to "09"

—

Table - A

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SERVICE

NUMBER

D07 EW PARABOLA 21 0-63(00h-3Fh) Must be set to "27" D08 EW TRAPEZIUM 0E 0-31(00h-1Fh) Must be set to "0B" D09 EW CORNER 0C 0-15(00h-0Fh) Must be set to "08" D10 AFC GAIN 02 0-3(00h-03h) Must be set to "02" D11 V EHT 07 0-7(00h-07h) Must be set to "04" D12 H EHT 03 0-7(00h-07h) Must be set to "03"

EX1 FAO VOLUME 24 0-50(00h-32h) Must be set to "24" EX2 CC-POSITION 21 0-127(00h-7Fh) EX3 INT 7A 0-255(00h-FFh) Must be set to "7A" EX4 A-ATT 5A 0-127 EX5 TUNER data 00 0-3(00h-03h) Must be to "00" EX6 SYNC SLICE LEVEL 36 0-255(00h-FFh) Must be to "36"

OP1 OPTION1 F7 0-255(00h-FFh) Must be set to "F7" OP2 OPTION2 F9 0-7(00h-07h) OP3 OPTION3 0F 0-255(00h-FFh)

M01 INPUT LEVEL 09 0-15(00h-0Fh) Must be set to "09" M02 MTS VCO 24 0-63(00h-3Fh) M03 FILTER 1F 0-63(00h-3Fh) M04 WIDEBAND 18 0-63(00h-3Fh) M05 SPECTRAL 10 0-63(00h-3Fh)

ADJUSTMENT ITEM

INITIAL VALUE

DA T A

ADJUSTMENT CONTENTS

RANGE

Table - A

Holding down both the VOL-up and CH-up buttons on the TV set at ser vice mode for more than 2 seconds will automatically write the above initial values into IC2102.

PART REPLACED

IC2001 IC201

IC2102

CRT IC3001

IC1801

NECESSARY UNNECESSARY

ADJUSTMENT

X X X

NOTES

Data is stored in IC2102. The adjustment is needed to compensate for characteristics of parts

including IC201 and MTS level (M01). Holding down both the VOL-up and CH-up buttons on the TV set in

the service mode for more than 2 seconds will automatically write the above initial values into IC2102. Then perf orm a complete adjustment.

Adjust items related to picture tube only. Adjust items related to MTS only (M01~M20).

Adjust items related to P-IN-P only (P01~P08).

Table - B

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SERVICE ADJUSTMENT

RF AGC Adjustment

1. Receive a good local channel.

2. Enter the service mode and select the service adjustment "R01".

3. Set the data value to point where no noise or beat appears.

4. Select another channel to confirm that no noise or beat appears. Note 1 : You will have to come out of the service

mode to select another channel.

Note 2 : Setting the data to "00" will produce a black

raster.

Screen Adjustment

1. Receive a good local channel.

2. Enter the service mode and select the service adjustment "V03" and set the data value to "00" to set the color level to minimum. (Record original data code under adjustment "V03" before changing) You may skip this step, if you selected a B/W picture or monoscope pattern.

3. Select the service adjustment "V18" and adjust the data value to "01", this turn off the luminance signal (Y-mute).

4. Adjust the master screen control until the raster darkens to the point where raster is barely seen.

5. Adjust the service adjustments "V06" red, "V07" green and "V08" blue to obtain a good grey scale with normal whites at low brightness level.

6. Select the service adjustment "V18" and reset data to "00". Select the service adjustment "V03" and reset data to obtain normal color level.

7. For component input, the data value of "V46" red, "V47" green and "V48" blue is adjusted to follow the data value of "V06", "V07" and "V08" respectively.

8. Reset the master screen control to obtain normal brightness range.

Sub-picture and Sub-Bright Adjustments

1. Receive the window pattern signal.

• RF INPUT (TU51)

2. Get into service adjustment data "V01" and "V05" and set the luminance as shown in figure "A" and "B" as below respectively.

• COMPONENT INPUT

3. Get in service adjustment data "V42" and "V45" and set the luminance as shown in figure "A" and "B" as below respectively.

A B

VOLTAGE CONFIRMATION

A: 92±10cd/m B:1.1±0.5cd/m2

Sub-Tint Adjustment

1. Receive the half color bar signal.

• RF INPUT (TU51)

2. Get into Y-Mute by R/C, or by setting the "V18" bus

data to "01".

3. Vary the "V02" bus data until the waveform becomes

as stated below.

LEVEL

B-AMP Base waveform in step (TP47B)

White Balance Adjustment

1. Receive a good local channel.

2. Enter the service mode and select the service adjustment "V03" and set to "00" (minimum color)(Record original data code under adjustment "V03" before changing). "V03" does not have to be adjusted, if you selected a B/W picture or monoscope pattern.

3. Alternately adjust the service adjustment data of "V09" and "V10" until a good grey scale with normal whites is obtained. (RF Input)

4. For component input, the data value of "V49" and "V50" is adjusted to follow the data value of "V09" and "V10" respectively.

5. Select the service adjustment "V03" and reset data to obtain normal color level.

• AV INPUT

4. Input data of "V41" to minus 5 step from "V02" data.

Sub-Color Adjustment

1. Receive a good local channel.

2. Make sure the customer color control is set to center position .

• RF INPUT (TU51)

3. Enter the service mode and select service adjustment "V03".

4. Adjust "V03" data value to obtain a normal color level.

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Vertical-Size and Linearity Adjustments

1. Receive a good local channel.

2. Enter the service mode and select the service adjustment "D03" for V-size.

3. Adjust the "D03" bus data to get the proper V-size.

4. For V-linearity adjustment, select data bus "D05" and adjust to get the proper vertical linearity. Note: Aging for 10 min before adjustment. After the

adjustment of V-center and V-size, readjustment for this V-line.

Vertical Phase Adjustment

1. Enter the service mode and select the service adjustment "D01".

2. Adjust "D01" data value so that picture is centered.

Horizontal Position Adjustment

1. Receive a good local channel.

2. Enter the service mode and select the service adjustment "D02".

3. Adjust "D02" data value so that picture is centered.

EW-Corner

1. Receive a good local channel.

2. Enter the service mode and select the service adjustment "D09" for EW-Corner.

3. Adjust the "D09" bus data to get the best linearity for 4 corner points.

Other Adjustments

1. Enter the service mode.

2. Adjust the following data values as listed below.

SERVICE ADJUST DATA(Hex)

POSITION ITEM

OP1 OPTION1 E7 OP2 OPTION2 B9 OP3 OPTION3 0E

Caption Position Adjustment (Horizontal)

1. Receive a good local channel.

2. Enter the service mode and select the service adjustment "EX2".

3. A black text bo x appears on the screen. (see

below)

4. Adjust "EX2" data value so that text box is positioned in the center of the screen.

Figure

Horizontal-Size Adjustment

1. Receive a good local channel.

2. Enter the service mode and select the service adjustment "D04" for H-size.

3. Adjust the "D04" bus data to get the proper H-size.

EW-Parabola

1. Receive a good local channel.

2. Enter the service mode and select the service adjustment "D07" for EW parabola.

3. Adjust the "D07" bus data to get the proper vertical straight line for both left and right side.

EW-Trapezium

Figure B.

1. Receive a good local channel.

2. Enter the service mode and select the service adjustment "D08" for EW-Trapezium.

3. Adjust the "D08" bus data to get the best position display.

Ë MTS ADJUSTMENT

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MTS Level Adjustment

1. Receive the following composite signal. Monaural signal: 400Hz, 100% modulation

2. Set the sound volume above 1.

3. Connect the rms voltmeter to pin (39) of IC3001.

4. Enter the service mode and select the service adjustment "M01" and set to "09".

5. Enter the service mode and select the service adjustment "EX4".

6. Adjust the data so that rms voltmeter reads 490±10mVrms.

7. For 2nd Tuner, adjust the "M06" until the voltage of pin (36) of IC3001 becomes 490±10mVrms.

MTS VCO Adjustment

1. Keep the unit in no-signal state.

2. Connect the frequency counter to pin (39) of IC3001.

3. Connect a capacitor (100µF, 50V) in between positive(+) side of C3005 and ground.

4. Enter the service mode and select the service adjustment "M02"

5. Adjust the data so that the frequency counter reads

62.94 ±0.75kHz.

Separation Adjustment

1. Input "SIGNAL 1" (TU51and TU52) and vary the "M04" and "M07" bus data to get the minimun AC voltage to pin (39) of IC3001.

2. Input "SIGNAL 2" (TU51and TU52) and vary the "M05" and "M08" bus data to get the minimun AC voltage to pin (39) of IC3001. SIGNAL 1: SIGNAL 2: 3kHz, 30% modulation, Lch only, NR-ON Check the output of the speaker at the maximum volume as stated below. Confirmation spec:

ADJ spec: above 25 dB CHK spec: above 20 dB

300Hz, 30% modulation, Lch only, NR-ON

Filter Adjustment

1. Feed the following stereo pilot signal to pin (14) of IC3001 . Stereo pilot signal: 9.4kHz, 600mVrms.

2. Enter the service mode and select the service adjustment "M03".

3. Adjust the data until "OK" appears in position on the screen. Make sure the "OK" is displayed almost at the center of the data range.

CHASSIS LAYOUT

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