TOSHIBA 36A50 Service Manual

Televisión a color

Tabla de contenidos Capítulo 1: Ajustes generales Ins trucciones de seguridad

36A50

 Ajus tes iniciales (para 13, 14, 19, 20) Modo de ser vicio Modo de dise ño Ajus tes eléctricos R evisión de circuitos Capítulo 2: Información específica F ijación y ajuste de datos Localizaci ón de controles Pr ogramando la memoria de canales Diag rama a bloques del circuito R eemplazo del gabinete y del chasis V ista inferior de las placas de circuito impreso V ista de terminales de transistores Especificaciones Diagrama esquemático Segur idad Pr incipal Ex citador PIP/CRT

FILE NO. 020-200005

SERVICE MANUAL

COLOR TELEVISION

N0ES Chassis

36A50

(TAC0010)

PRINTED IN U.S.A. Apr., 2000 U

CHAPTER 1 GENERAL ADJUSTMENTS

SAFETY INSTRUCTIONS........................................................................................................................................3

SET-UP ADJUSTMENT............................................................................................................................................4

SERVICE MODE ...................................................................................................................................................... 8

DESIGN MODE ...................................................................................................................................................... 11

ELECTRICAL ADJUSTMENTS ..............................................................................................................................12

CIRCUIT CHECKS .................................................................................................................................................16

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

CHAPTER 2 SPECIFIC INFORMATIONS

SETTING & ADJUSTING DATA .............................................................................................................................17

LOCATION OF CONTROLS...................................................................................................................................18

PROGRAMMING CHANNEL MEMORY.................................................................................................................20

CIRCUIT BLOCK DIAGRAM ..................................................................................................................................21

CHASSIS AND CABINET REPLACEMENT PARTS LIST......................................................................................22

PC BOARDS BOTTOM VIEW ................................................................................................................................31

TERMINAL VIEW OF TRANSISTORS ...................................................................................................................34

SPECIFICATIONS ..................................................................................................................................................37

APPENDIX:

CIRCUIT DIAGRAM

– 2 –

CHAPTER 1 GENERAL ADJUSTMENTS

AC VOLTMETER

0.15µF

Good earth ground such as a water pipe, conduit, etc.

Place this probe on each exposed metallic part.

1500 ohm 10 watt

SAFETY INSTRUCTIONS

WARNING: BEFORE SERVICING THIS CHASSIS, READ THE “X-RAY RADIATION PRECAUTION”, “SAFETY PRECAU-

TION” AND “PRODUCT SAFETY NOTICE” INSTRUCTIONS BELOW.

X-RAY RADIATION PRECAUTION

1. Excessive high voltage can produce potentially hazardous X-RAY RADIATION. To avoid such hazards, the high voltage must not be abov e the specified limit. The nominal value of the high voltage of this receiver is (A) kV at zero beam current (minimum brightness) under a 120V AC power source. The high voltage must not, under any circumstances, exceed (B) kV.

Refer to table-1 for high voltage (A), (B). (See SETTING & ADJUSTING DATA on page 17)

Each time a receiver requires servicing, the high voltage should be checked f ollowing the HIGH VOLTAGE CHECK procedure in this manual. It is recommended that the reading of the high voltage be recorded as a part of the service record. It is important to use an accurate and reliable high voltage meter.

SAFETY PRECAUTION

2. This receiver is equipped with a Fail Safe (FS) circuit which prevents the receiver from producing an excessively high voltage ev en if the B+ voltage increases abnormally. Each time the receiver is serviced, the FS circuit must be checked to determine that the circuit is properly functioning, following the FS CIRCUIT CHECK procedure in this manual.

3. The only source of X-RAY RADIA TION in this TV receiver is the picture tube. F or contin ued X-RAY RADIATION protection, the replacement tube must be exactly the same type tube as specified in the parts list.

4. Some part in this receiver have special safety-related characteristics for X-RAY RADIATION protection. For continued safety, parts replacement should be undertaken only after referring to the PRODUCT SAFETY NO TICE below.

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

WARNING : Service should not be attempted by any one unf amiliar with the necessary precautions on this receiver. The following are the necessary precautions to be observed before servicing this chassis.

1. An isolation Transf ormer should be connected in the power line between the receiver and the AC line bef ore an y service is performed on the receiver.

2. Always discharge the picture tube anode to the CRT conductive coating before handling the picture tube . The picture tube is highly evacuated and if broken, glass fragments will be violently expelled. Use shatter proof goggles and keep picture tube away from the unprotected body while handling.

3. When replacing a chassis in the cabinet, always be certain that all the protective devices are put back in place, such as; non-metallic control knobs, insulating covers, shields, isolation resistor-capacitor network etc.

4. Before returning the set to the customer, always perform an AC leakage current check on the e xposed metallic parts of the cabinet, such as antennas, terminals, screwheads, metal overlays, control shafts etc. to be sure the set is safe to operate without danger of electrical shock. Plug the AC line cord directly into a 120V AC outlet (do not use a line isolation transformer during this check). Use an AC voltmeter having 5000 ohms per volt or more sensitivity in the following manner:

Connect a 1500 ohm 10 watt resistor, paralleled b y a 0.15 µF, AC type capacitor, between a known good earth ground (water pipe, conduit, etc.) and the exposed metallic parts, one at a time. Measure the AC voltage across the combination of 1500 ohm resistor and 0.15 µF capacitor. Reverse the AC plug at the AC outlet and repeat AC voltage measurements for each exposed metallic part. Voltage measured must not exceed 0.3 v olts rms. This corresponds to 0.2 milliamp. AC. Any value exceeding this limit constitutes a potential shock hazard and must be corrected immediately.

Many electrical and mechanical parts in this chassis have special safety-related characteristics. These characteristics are often passed unnoticed by a visual inspection and the protection afforded by them cannot necessarily be obtained b y using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in this manual and its supplements; electrical components having such features are identified by the international hazard symbols on the schematic diagram and the parts list. Before replacing any of these components, read the parts list in this manual carefully. The use of substitute replacement parts which do not have the same safety characteristics as specified in the parts list may create shock, fire, X-ray radiation or other hazards.

PRODUCT SAFETY NOTICE

– 3 –

WARNING: BEFORE SERVICING THIS CHASSIS, READ THE “X-RAY RADIATION PRECAUTION”, “SAFETY PRECAUTION” AND “PRODUCT SAFETY NOTICE” ON PAGE 3 OF THIS MANUAL.

■ The following adjustments should be made when a complete realignment is required or a new picture tube is installed. Perform the adjustments in order as follows :

1. Color Purity

2. Convergence

3. White Balance

Note: The PURITY/CONVERGENCE MAGNET assembly and rubber wedges need mechanical positioning.

Refer to figure 1.

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

COLOR PURITY ADJUSTMENT NOTE : Before attempting any purity adjustments, the receiver

1. Demagnetize the picture tube and cabinet using a degauss-

2. Set the brightness and contrast to maximum.

3. Use a green raster from among the built-in test signals.

4. Loosen the clamp screw holding the yoke and slide the

Mounting position of the purity magnet assembly should fit to same position as old one because slightly difference to the position depend on a kind of tube.

There are no adjustment of purity and convergence in some picture tube (Unified with purity magnet)

should be operated for at least fifteen minutes.

ing coil.

yoke backward or forward to provide vertical green belt (zone) in the picture screen.

SET-UP ADJUSTMENT (FOR 13”, 14”, 19”, 20”)

5. Remove the Rubber Wedges.

6. Rotate and spread the tabs of the purity magnet (See figure 2.) around the neck of the picture tube until the green belt is in the center of the screen. At the same time , enter the raster vertically.

7. Slowly move the yoke forward or backward until a uniform green screen is obtained. Tighten the clamp screw of the yoke temporarily.

8. Check the purity of the red and blue raster.

GLASS CLOTH TAPES

DEFLECTION YOKE

14mm(13", 14") 19mm(19", 20")

PURITY/ CONVERGENCE MAGNET ASS'Y

TEMPORARY MOUNTING

RUBBER WEDGE

ADHESIVE

DEFLECTION YOKE

Figure 1.

– 4 –

CONVERGENCE ADJUSTMENTS

NOTE: Before attempting any convergence adjustments, the

receiver should be operated for at least fifteen minutes.

■ CENTER CONVERGENCE ADJUSTMENT

1. Use the cross-dot pattern from among the built-in test signals.

2. Set the brightness and contrast for well defined pattern.

3. Adjust two tabs of the 4-Pole Magnets to change the angle between them (See figure 2.) and superimpose red and blue vertical lines in the center area of the picture screen.

4. Turn the both tabs at the same time keeping the angle constant to superimpose red and blue horizontal lines at the center of the screen.

5. Adjust two tabs of 6-Pole Magnets to superimpose red/ blue line and green one. Adjusting the angle affects the vertical lines and rotating both magnets affects the horizontal lines.

6. Repeat adjustments 3, 4, 5 keeping in mind red, green and blue movement, because 4-Pole Magnets and 6-Pole Magnets have mutual interaction and make dot movement complex.

6-POLE

4-POLE

MAGNETS

ADJUST THE ANGLE (VERTICAL LINES)

■ CIRCUMFERENCE CONVERGENCE ADJUSTMENT

1. Loosen the clamping screw of deflection yoke slightly to allow the yoke to tilt.

2. Temporarily put a wedge as shown in figure 1. (Do not remove cover paper on adhesive part of the wedge.)

3. Tilt front of the deflection yoke up or down to obtain better convergence in circumference. (See figure 3.) Push the mounted wedge into the space between picture tube and the yoke to fix the yoke temporarily.

4. Put other wedge into bottom space and remove the cover paper to stick.

5. Tilt front of the yoke right or left to obtain better convergence in circumference. (See figure 3.)

6. Keep the yoke position and put another wedge in either upper space. Remove cover paper and stick the wedge on picture tube to fix the yoke.

7. Detach the temporarily mounted wedge and put it in another upper space. Stick it on picture tube to fix the yoke.

8. After fixing three wedges, recheck overall convergence. Tighten the screw firmly to fix the yoke and check the y oke is firm.

9. Stick three adhesive tapes on wedges as shown in figure

FIXED

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

ROTATE TWO TABS AT THE SAME TIME (HORIZONTAL LINES)

PURITY MAGNETS

CONVERGENCE MAGNET ASSEMBLY ADJUSTMENT OF MAGNETS

Figure 2.

BLU RED

BLU

RED

4-POLE MAGNETS MOVEMENT

BGR

R G B

RGB

RED/BLU

GRN

Center Convergence by Convergence Magnets

B G R

RED/BLU GRN

6-POLE MAGNETS MOVEMENT

B G R

BGR

RGB

R G B

INCLINE THE YOKE UP (OR DOWN)

Circumference Convergence by DEF Yoke

Figure 3. Dot Movement Pattern

INCLINE THE YOKE RIGHT (OR LEFT)

– 5 –

WARNING: BEFORE SERVICING THIS CHASSIS, READ THE “X-RAY RADIATION PRECAUTION”, “SAFETY PRECAUTION” AND “PRODUCT SAFETY NOTICE” ON PAGE 3 OF THIS MANUAL.

■ The following adjustments should be made when a complete realignment is required or a new picture tube is installed. Perform the adjustments in order as follows :

1. Color Purity

2. Convergence

3. White Balance

Note: The PURITY/CONVERGENCE MAGNET assembly and rubber wedges need mechanical positioning.

Refer to figure 1.

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

COLOR PURITY ADJUSTMENT

NOTE : Before attempting any purity adjustments, the

1. Evenly degauss the entire screen.

2. Set the CONTRAST and BRIGHTNESS Controls to

3. Display built-in green raster using the TEST SIGNAL

4. Loosen the clamp screw holding the deflection yoke

5. Slide the yoke forward or backward to provide vertical

6. Rotate and spread the tabs of the purity magnet (See

Mounting position of the purity magnet assembly should fit to same position as old one because slightly difference to the position depend on a kind of tube.

There are no adjustment of purity and convergence in some picture tube (Unified with purity magnet)

receiver should be operated for at least fifteen minutes.

the maximum. SELECTION function. (and remove the Rubber Wedges). green belt (zone) in the picture screen. figure 4.) around the neck of the picture tube until the

green belt is in the center of the screen. At the same time, center the raster vertically by adjusting the magnet as shown below.

(FOR 35”, 36”)

Xv Coil

DEFLECTION YOKE

1-5/8”

PURITY/ CONV. MAGNET

Green Belt

7. Move the yoke slowly forward or backward until a uniform green screen is obtained. Tighten the clamp scre w of the yoke temporarily.

8. Check the purity of the red and blue raster.

9. Put four wedges into the space between the picture tube and the yoke to hold the yoke in the adjusted position. (See figure 2.) Do not tilt the yoke by excessive insertion of the wedge.

10. Remove cover paper of wedge and stick wedges on the tube to fix the yoke in the adjusted position. Fix the wedges with glass cloth tapes.

Figure 1.

RUBBER WEDGES

Adhesive

DEFLECTION YOKE

Figure 2.

– 6 –

CONVERGENCE ADJUSTMENTS

NOTE: Before attempting any convergence adjustments,

the receiver should be operated for at least fifteen minutes.

■ CENTER CONVERGENCE ADJUSTMENT

1. Display built-in cross-dot pattern using the TEST SIGNAL SELECTION function.

2. Adjust the BRIGHTNESS and CONTRAST Controls for well defined pattern.

3. Loosen the tightening ring and adjust two tabs of the 4-Pole Magnets to change the angle between them (See figure 4.) and superimpose red and blue vertical lines in the center area of the picture screen. (See figure 3.)

4. Turn the both tabs at the same time keeping the constant angle to superimpose red and blue horizontal lines at the centre of the screen. (See figure 3.)

5. Adjust two tabs of 6-Pole Magnets to superimpose red/ blue line with green one. Adjusting the angle affects the vertical lines and rotating both magnets affects the horizontal lines.

6. Repeat adjustments 3, 4, 5 keeping in mind red, green and blue movement, because 4-Pole Magnets and 6Pole magnets interact and make dot movement complex.

7. After completing the “CENTER CONVERGENCE ADJUSTMENT” tighten the tightening ring to fix the magnets.

6-POLE MAGNETS

PURITY MAGNETS

ADJUST THE ANGLE (VERTICAL LINES)

4-POLE MAGNETS

PURITY/CONVERGENCE MAGNETS

FIXED

ROTATE TWO TABS AT THE SAME TIME (HORIZONTAL LINES)

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

BLU RED

BLU

RED

4-POLE MAGNETS MOVEMENT

Center Convergence by Convergence Magnets

■ Xv COIL ADJUSTMENT

Adjust the Xv coil (on the deflection yoke) to correct misconvergence at both sides on screen. Use a hexagonal tip stick (plastic) to adjust the core of coil.

Clockwise Adjustment Counterclockwise Adjustment

Clockwise Adjustment

RED/BLUE

Figure 3.

Counterclockwise Adjustment

RED/BLUE GRN

GRN

6-POLE MAGNETS MOVEMENT

ADJUSTMENT OF MAGNETS

Figure 4.

■ SCREEN-CORNER CONVERGENCE

When the misconvergence is still evident on corners even though the above adjustment is done, use the ferrite sheet (Part No. 23993622) to correct misconvergence.

1. Put ferrite sheets into the space under the yoke. Decide such position that misconvergence becomes minimum, watching picture screen. (See figure below .)

2. Remove cover paper of ferrite sheet to stick it in the place on the tube. Put adhesive tapes on ferrite sheets to fix.

Ferrite Sheets

Ferrite

Sheets

Xv Cross Pattern View

XV Cross Pattern View

For correcting misconvergence on the position A

– 7 –

1. ENTERING TO SERVICE MODE

1) Press MUTE button once on Remote Control.

MUTE

SERVICE MODE

2) Press MUTE button again to keep pressing.

3) While pressing the MUTE button, press MENU button on TV set.

(Service mode display)

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

2. DISPLAYING THE ADJUSTMENT MENU

1) Press MENU button on TV.

Service mode

3. KEY FUNCTION IN THE SERVICE MODE

The following key entry during display of adjustment menu provides special functions. A single horizontal line ON/OFF: TV (ANT)/VIDEO button (on TV)

Test signal selection : TV (ANT)/VIDEO button (on Remote) Selection of the adjustment items : Channel s/t (on TV or Remote) Change of the data value : Volume s/t (on TV or Remote) Adjustment menu mode ON/OFF : MENU button (on TV) Initialization of the memory (QA02) : RECALL+Channel (s) button on TV Initialization of the self diagnostic data: RECALL+Channel (t) button on TV

“RCUT” selection : 1 button “GCUT” selection : 2 button “BCUT” selection : 3 button “CNTX” selection : 4 button “COLC” selection : 5 button “TNTC” selection : 6 button Test audio signal ON/OFF (1kHz) : 8 button Self diagnostic display ON/OFF : 9 button

Adjustment mode

Press

Item Data

– 8 –

4. SELECTING THE ADJUSTING ITEMS

1) Every pressing of CHANNEL s button in the service mode changes the adjustment items in the order of table-2. (t button for reverse order)

Refer to table-2 for preset data of adjustment mode. (See SETTING & ADJUSTING DATA on page 17)

5. ADJUSTING THE DATA

1) Pressing of VOLUME s or t button will cahnge the value of data in the range from 00H to FFH.

The variable range depends on the adjusting item.

6. EXIT FROM SERVICE MODE

1) Pressing POWER button to turn off the TV once.

■ INITIALIZATION OF MEMORY DATA OF QA02

After replacing QA02, the following initialization is required.

1. Enter the service mode, then select any register item.

2. Press and hold the RECALL button on the Remote, then press the CHANNEL s button on the TV. The initialization of QA02 has been complated.

3. Check the picture carefully. If necessary, adjust any adjustment item above. Perform “Programming Channel Memory” on owner's manual.

CAUTION: Never attempt to initialize the data unless QA02 has been replaced.

7. TEST SIGNAL SELECTION

1) Every pressing of TV/VIDEO button on the Remote Control in the Service mode changes the built-in test patterns on screen in the following order.

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

Normal picture Black cross-bar

on green raster

Red raster Green raster Blue raster All black All white White and black Black cross-bar White cross-bar

2) Press “8” button while any built-in test pattern to on the screen to output the 1 kHz sound. Press the button again to cut off the sound.

Note: If the video cable is connected to the VIDEO1 INPUT jack, the

built-in pattern signals are not displayed.

H signal (black) H signal (white) White cross-dot Black cross-dot White cross-hatch

Black cross-hatch

Signals Picture

• Red raster

• Green raster

• Blue raster

• All Black

• All White

• Black & White

• Black cross-bar

• White cross-bar

• Black cross-bar on green raster

• Black cross-hatch

• White cross-hatch

• Black cross-dot

• White cross-dot

• H signal (white)

• H signal (black)

The signals marked with are not usable to display in the Test signal for some model.

– 9 –

8. SELF DIAGNOSTIC FUNCTION

1) Press “9” button on Remote Control during display of adjustment menu in the service mode. The diagnosis will begin to check if interface among IC’s are executed properly.

2) During diagnosis, the following displays are shown.

SELF CHECK

1 2 3 4 5

NO. 23XXXXXX POWER : 000 BUS LINE : OK BUS CONT : OK BLOCK : UV V1 V2 or V OUT1 VOUT2 SYNC QV01 QV01S

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

1 Part number of microprocessor (QA01)

2 Operation number of protection circuit (current limiter) . . . . “000” is normal.

3 BUS line check “OK” ................... Normal

4 BUS line ACK (acknowledge) check

5 Sync. signal check Green display..... Normal

“SCL-GND” or “NG” .......... SCL-GND short circuit

“SDA-GND” or “NG”.......... SDA-GND short circuit

“SCL-SDA” or “NG”........... SCL-SDA short circuit

“OK” ..................... Normal

Display of Location Number . . . . NG

(Display example) “QA02 NG”, “H001 NG”, “Q501 NG” etc. Note: The indication of failure place is only one place though failure places are plural. When repair

of a failure place finishes, the next failure place is indicated. (The order of priority of indication is left side.)

Cyan display ......No check

Red display ........ NG

UV........... TV mode

V1 ........... VIDEO 1 mode

V2 ........... VIDEO 2 mode

The items marked with are not usable to display in the SELF DIAGNOSTIC FUNCTION for some model.

– 10 –

1. ENTERING TO DESIGN MODE

1) Select the Service mode.

DESIGN MODE

2) While pressing RECALL button on Remote and press MENU button on TV.

3) Press MENU button on TV.

S D

(Design mode) (Adjustment mode)

When QA02 is initialized, items “OPT0” and “OPT1” of DESIGN MODE are set to the data of the representative model of this chassis family. Therefore, because ON-SCREEN specification remains in the state of the representative of model. This model is required to reset the data of items “OPT0” and “OPT1”.

2. SELECTING THE ADJUSTING ITEMS

Every pressing of CHANNEL t button in the design mode changes the adjustment items in the order of table-3. (s button for reverse order)

Refer to table-3 for data of design mode. (See SETTING & ADJUSTING DATA on page 17)

3. ADJUSTING THE DATA

Pressing of VOLUME s or t button will change the value of data.

Press

ITEM DATA

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

– 11 –

ELECTRICAL ADJUSTMENTS

ITEM ADJUSTMENT PROCEDURE

FOCUS VR ADJ

SUB-BRIGHTNESS (BRTC)

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

SUB-COLOR (COLC) SUB-TINT (TNTC)

1. Enter the service mode, then select any register item.

2. Press the TV/VIDEO button on the Remote until the black cross-bar pattern appears on the screen.

3. Adjust the FOCUS control (on T461) for well defined scanning lines on the picture screen.

1. Constrict the picture height until the vertical retrace line appears adjusting the HEIGHT control on the MAIN board.

2. Adjust the CONTRAST to the minimum and BRIGHTNESS to the center.

3. Enter the service mode, then select “BRTC” register.

4. Adjust the data value so the belt of vertical retrace line just disappear.

5. Adjust the CONTRAST for the desired contrast.

6. Adjust the HEIGHT control.

Vertical retrace line

1. Receive color-bar signal from color-bar generator.

2. Press the RESET button.

3. Connect oscilloscope to base of Q906 on CRT-D board.

4. Enter the service mode, then select “COLC”.

5. Adjust the SUB-COLOR by pressing the VOLUME s or t button to achieve about 1V0-p of blue bar.

6. Select “TNTC” register.

7. Adjust the data value to obtain the blue bar to magenta bar ratio of 3:2 as shown.

Magenta

Blue

3 (1.8V

8. Select “COLC” register.

9. Adjust the data value to achieve 1.80-p of blue bar on scope.

10. Check the picture with off-air signal.

0-P

)

WIDTH (WID)

1. Call up the adjustment mode display, then select the item WID.

2. Press the VOLUME s or t button to get the picture so the left and right edges of raster begins to lack.

3. Press the VOLUME s or t button to advance the data by 7 steps.

Note : Check the horizontal picture position is correct.

– 12 –

ITEM ADJUSTMENT PROCEDURE

E-W PARABOLA (DPC)

HORIZONTAL POSITION (HPOS) VERTICAL POSITION (VPOS)

HEIGHT (HIT)

1. Call up the adjustment mode display, then select the Item DPC.

2. Press the TV/VIDEO button on Remote until the cross-hatch pattern appears on the screen.

3. Press the VOLUME s or t button to mak e v ertical lines straight as shown below.

1. Call up the adjustment mode display, then select the item HPOS or VPOS.

2. Press the TV/VIDEO button on Remote until the white cross-bar or black cross-bar pattern appears on the screen.

3. Adjust the HORIZONT AL and VER TICAL position alternately by pressing the VOLUME s or t button for proper picture position.

4. Check the picture with off-air signal.

1. Call up the adjustment mode display, then select the item HIT.

2. Press the VOLUME s or t button to get the picture so the top of raster begins to lack.

3. Press the VOLUME s button to advance the data by 8 steps.

Note : Check the vertical picture position is correct.

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

WHITE BALANCE (RCUT) (GCUT) (BCUT) (GDRV) (BDRV)

1. Adjust the CONTRAST control to the center, and BRIGHTNESS control to the

maximum.

2. Call up the adjustment mode display , and press the TV/VIDEO button on Remote

until the white and black pattern appears on the screen.

3. Adjust the following item with the CHANNEL s/t and VOLUME s/t buttons.

RCUT GCUT BCUT

4. Press the TV/VIDEO button on TV to displa y a single horizontal line on the screen.

5. Turn the SCREEN control (FBT) fully counterclockwise and gr adually rotate clock-

wise until the first horizontal line appears slightly on the screen.

6. Press the TV/VIDEO button to display the normal picture.

7. Adjust the remaining two “?CUT” items (CHANNEL s/t → TV/VIDEO → VOL-

UME s/t in order) to obtain the slightly lighted horizontal line in the same levels of three (red, green, blue) colors. The line should be white if the adjustments are proper.

Data : 40H Data : 40H Data : 40H

Bright area Adjust "GDRV" or "BDRV" to be white.

Dark area Fine adjust "RCUT", "GCUT" or "BCUT" to be black.

GDRV Data : 40H BDRV Data : 40H

– 13 –

MTS ADJUSTMENT (FOR N7S CHASSIS)

No. ITEM INPUT SIGNAL ADJUSTMENT PROCEDURE

ATTENUATOR

(ATT)

STEREO VCO

(STVC)

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

SAP VCO

(SAVC)

• 1kHz 30% mod. → ANT terminal

1. Connect rms meter to pin 12 of H002.

2. Display item ATT on screen.

3. Change data by V olume s/t buttons so that output at pin 12 of H002 becomes value as close as 142mVrms.

• No signal 1. Display item STVC, and connect pin 9 of H002 to ground.

2. Connect frequency counter to pin 12 of H002.

3. Change data by Volume s/t buttons so that the reading of counter becomes value as close as 4fH (62.936kHz).

• 78.670kHz 147mVrms → pin 9 of H002

• Monaural signal → ANT

1. Display item SAVC.

2. Change data by V olume s/t buttons so that the data becomes in the center of range for STA7=0 and STA8=1.

SAVC

XXH

STA7:0 STA8:1

STEREO FILTER

(STRF)

SAP FILTER

(SAPF)

STEREO SEPARATION

(WBAN)

• 9.4kHz 600mVrm → pin 9 of H002 Monaural signal → ANT

• 88kHz 120mVrms → pin 9 of H002

• Monaural signal → ANT

• STEREO 300Hz R-channel

only → ANT

1. Display item STRF on screen.

2. Change data by V olume s/t buttons so that the data becomes in the center of range for STA3=1.

STRF

XXH

STA3:1

1. Display item SAPF.

2. Change data by V olume s/t buttons so that the data becomes in the center of range for STA4=1.

SAPF

XXH

STA4:1

1. Select “STEREO” mode from the MTS function in the Audio menu.

2. Display item WBAN on screen.

3. Connect oscilloscope to pin 14 of H002.

4. Change data by Volume s/t buttons so that 300Hz element on scope becomes minimum.

(SPEC)

• STEREO 3kHz R-channel only → ANT

– 14 –

5. Display item SPEC on screen.

6. Change data by Volume s/t buttons so that 3kHz element on scope becomes minimum.

MTS ADJUSTMENT (FOR N0ES CHASSIS)

No. ITEM INPUT SIGNAL ADJUSTMENT PROCEDURE

ATTENUATOR (ATT)

• 1kHz 30% mod. → ANT terminal

1. Connect rms meter to pin 34 of QG01.

2. Display item ATT on screen.

3. Change data by VOLUME s/t buttons so that the reading of meter becomes value as close as 137mVrms.

STEREO VCO (STVC)

• No signal 1. Short circuit RG44 with a jumper wire.

2. Display item STVC on screen.

3. Connect frequency counter to pin 34 of QG01.

4. Change data by VOLUME s/t buttons so that the reading of counter becomes value as close as 15.73kHz.

STEREO FILTER (STRF)

• 15.734kHz 30mV(rms) 1. Unsolder the solder link SL02.

2. Display item STRF on screen.

15.734KHz 30mV(rms)

H001

SL02

CG44

RG43

CG07

RG44

QG01

3. Connect oscilloscope to pin 34 of QG01.

4. Change data by VOLUME s/t button to minimize AC output level on scope.

5. Resolder SL02.

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

STEREO SEPARATION

(WBAN)

(SPEC)

SAP VCO

(SAVC)

• STEREO 300Hz R-channel only → ANT

1. Display item WBAN on screen.

2. Connect oscilloscope to pin 35 of QG01.

3. Change data by VOLUME s/t buttons so that 300Hz element on scope becomes minimum.

• STEREO 3kHz R-channel only → ANT

4. Display item SPEC on screen.

5. Change data by Volume s/t buttons so that 3kHz element on scope becomes minimum.

• No signal 1. Shortcircuit RG44 with a short jumper.

2. Connect 1Mohm resistor between pin 12 of

H001

QG01

CG44 RG43

RG44

QG01 and ground.

3. Display item SAVC on screen.

4. Connect frequency counter to pin 34 of QG01.

5. Change data by VOLUME s/t buttons so that the reading of counter becomes value as close as 78.67kHz.

6. Remove the short jumper and 1M ohm resistor.

– 15 –

CIRCUIT CHECKS

HIGH VOL T A GE CHECK CAUTION: There is no HIGH VOLTAGE ADJUSTMENT on

this chassis. Checking should be done following the steps below .

1. Connect an accurate high voltage meter to the second anode of the picture tube.

2. Turn on the receiver. Set the BRIGHTNESS and CONTRAST controls to minimum (zero beam current).

3. High voltage must be measured below (B) kV. Refer to table-1 for high voltage (B).

(See SETTING & ADJUSTING DATA on next page)

GENERAL ADJUSTMENTSSPECIFIC INFORMATIONS

4. Vary the BRIGHTNESS control to both extremes to be sure the high voltage does not exceed the limit under any conditions.

FS CIRCUIT CHECK

The Fail Safe (FS) circuit check is indispensable for the final check in servicing. Checking should be done following the steps below.

1. Turn the receiver on and press the RESET button.

2. Temporarily short TP-(R) and TP-(X) with a jumper wire. Raster and sound will disappear.

3. The receiver must remain in this state even after removing the jumper wire. This is the evidence that the FS circuit is functioning properly.

4. To obtain a picture again, temporarily turn the receiver off and allow the FS circuit more than 5 seconds to reset. Then turn the power switch on to produce a normal picture.

Troubleshooting Guide for Fail Safe Circuit

Check that the set returns to normal operation when pin 12 of Z801(or emitter of Q472) is grounded with jumper wire.

YES NO

Check the voltage across Capacitor C471 is approximately (C) volts.

Refer to table –4 for FBT detection voltage (C).

YES

Defective Fail Safe Circuit

(See SETTING & ADJUSTING DATA on next page.)

Faulty power circuit or horizontal circuit.

– 16 –

+ 39 hidden pages

TOSHIBA 36A50 Service Manual

TABLE OF CONTENTS

CHAPTER 1 GENERAL ADJUSTMENTS

SAFETY INSTRUCTIONS

SERVICE MODE

DESIGN MODE

ELECTRICAL ADJUSTMENTS