Panasonic CT-25G6E, CT-25G6CE, CT-25G6UE, CT-27G6E, CT-27G6DE Service Manual

...

ORDER NO. MTNC010306C1 B5

Service Manual

Color Television

Main Manual

(NA7D)

Panasonic

CT-27G6E/DE/UE

SP-2724E/UE

Models

Chassis

CT-25G6E AP361 CT-25G6CE AP361 CT-25G6UE AP361 CT-27G6E AP362 CT-27G6DE AP362 CT-27G6UE AP362

Quasar

Models

SP-2724E EC363 SP-2724UE EC363

Chassis

This Service manual is issued as a service guide for the models of the NA7D family listed above. Included are schematics, alignment procedures, disassembly procedures, and a parts list.

“WARNING! This Service Manu al is des igned for ex perienced re pair techni cians only a nd is not designed fo r use by th e general p ublic. It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product. Products powered by electricity should be se rviced or repaire d only by experienc ed professio nal techni cians. Any a ttem pt to service or repair the product or products dealt with in this Service Manual by anyone else could result in serious injury or death.”

The service technician is required to read and follow the “Safety Precautions” and “Important Safety Notice” in this Manual.

Important Safety Notice

Special components are used in this television set which are important for safety. These parts are identified on the schematic diagra m by the s ymbol and printed in BOLD TYPE on the replaceme nt part list. It is essential that

these critical parts are replaced with the manufacturer’s specified replacement part to prevent X-ray radiation, shock, fire or other hazards. Do not modify the original design without the manufacturer’s permission.

Safety Precautions

General Guidelines

An Isolation T ransformer should always be used during the servicing of a Receiver whose chassis is not isolated from AC power line. Use a transformer of adequate power rating as this protects the technician from accidents resulting in personal injury from electrical shocks. It will also pr otect the Receiver from being damaged by accidenta l shorting that may occur during servicing. When servicing, observe the original lead dress, especially in the high voltage circuit. Replace all damaged parts (also parts that show signs of overheating.) Always Replace Protective Devices, such as fishpaper, isolation resistors and capacitors, and shields after servicing the Receiver. Use only manufacturer’s recommended rating for fuses, circuits breakers, etc. High potentials are present when this Receiver is operating. Operation of the Receiver without the rear cover introduc es danger for el ectrical sho ck. Servicin g should not be performed by anyone who is not thoroughly familiar with the necessary precautions when servicing high-voltage equipment.

Extreme care should be p ra ctic ed wh en Handling the Picture Tube. Rough handling may cause it to implode

due to atmospheric pres sure. (14.7 lbs per sq. in.). D o not nick or scratch the glass or subject it to any undu e pressure. When handling, use safety goggles and heavy gloves for protection. Discharge the picture tube by shorting the anode to chassis ground (not to the cabinet or to other mounting hardware). When discharging con nect cold ground (i .e. da g ground lead) to the anode with a well insulated wire or use a grounding probe. Avoid prolonged exposure at close range to unshielded areas of the picture tube t o prevent exposure t o X-ray radiation. The T est Picture Tube used for servicing the chassis at the bench should incorporate safety glass and magnetic shieldi ng. The safety glass pr ovide shielding for the tube viewing area against X-ray radiation as well as implosion. T he magnetic shield lim its the X-ray radiation around the bell of the pict ure tube in addition to the restricting magnetic effects. When using a picture tube test jig for service, ensure that the jig is capable of handling 50kV without causing X-ray radiation. Before returning a serviced Receiver to the owner, the service technician must thoroughly test the unit to ensure that is completely safe to operate. Do not use a

line isolation transformer when testing.

Leakage Current Cold Check

Unplug the AC cord and connect a jumper between the two plug prongs. Measure the re si stance betw e e n th e j um p ere d AC pl ug and expose metallic parts such as screwheads, antenna terminals, control shafts, etc. If the exposed

metallic part has a return path to the chassis, the reading should be between 240kΩ and 5.2MΩ. If the exposed metallic part does not have a return path to the chassis, the reading should be infinite.

Leakage Current Hot Check (Fig. 1)

Plug the AC cord directly into the AC outlet. Do not use an isolation transformer during the check. Connect a 1.5kΩ 10 watt resistor in parallel with a

0.15µF capacitor between an exposed metallic part and ground. Use earth ground, for example a water pipe. Using a DVM with a 1000 ohms/volt sensitivity or higher, measure the AC potential across the resistor. Repeat the procedure and measure the voltage present with all other exposed metallic parts. Verify that any potential does not exceed 0.75 volt RMS. A leakage curr ent test er (suc h a S impson M odel 229, Sencore Model P R57 or equival ent) may be used in the above procedure, in which case any current measure must not exceed 0.5 milliamp. If any measurement is out of the specified limits, there is a possibility of a s hoc k haz ard and the Receiver mus t b e repaired and rechecked before it is returned to the customer.

Figure 1. Hot Check Circuit

X-ray Radiation

WARNING: The potential source of X-ray radiation in the

Receiver is in the High Voltage section and the picture tube. Refer to “X-Ray Protection Circuit Check & Adjustments” on page5 to confirm HHS voltage.

High Voltage (CRT Anode)

Set the brightness, picture, sharpness and color controls to minimu m (to obtain dark image). Measure the High Voltage. The high voltage should be

29.25kV ± 1.25kV. If the upper limit is out of toler ance, immediate service and correction is required.

Note: It is important to use an accurate, calibrated

high voltage meter.

- 2 -

Important Safety Notice . . . . . . . . . . . . . . . . . . 2

Safety Precautions . . . . . . . . . . . . . . . . . 2

Service Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . 4

X-Ray Protection Circuit Check

& Adjustments . . . . . . . . . . . . . . . . . 5

Receivers Feature Table . . . . . . . . . . . . . . . . . . 6

Location of Receiver Controls . . . . . . . . . . . . . 7

Location of Controls . . . . . . . . . . . . . . . . . . . . . 8

Service Adjustments

(Electronic Control). . . . . . . . . . . . . . . . . . 22

Sub-Contrast. . . . . . . . . . . . . . . . . . . . . 22

Sub-Brightness . . . . . . . . . . . . . . . . . . . 22

Tint/Color Adjustment . . . . . . . . . . . . . . 22

White Balance. . . . . . . . . . . . . . . . . . . . 23

Sub-Brightness Final Adjustment . . . . . 23

Horizontal Centering. . . . . . . . . . . . . . . 23

Vertical Size . . . . . . . . . . . . . . . . . . . . . 24

MTS Circuit Adjustment . . . . . . . . . . . . 24

Input Level Adjustment . . . . . . . . . . . . . 24

Stereo Separation Adjustment . . . . . . . 24

Clock Adjustment . . . . . . . . . . . . . . . . . 24

Service Adjustments

(Mechanical Controls). . . . . . . . . . . . . . . . 25

Disassembly for Service. . . . . . . . . . . . . . . . . . 9

Disassembly for CRT Replacement . . . . . . . . . 9

CRT Replacement . . . . . . . . . . . . . . . . . . . . . . . 9

Chassis Service Adjustment Procedures . . . 10

130.0V B+ Voltage Confirmation . . . . . 10

Source Voltage Chart . . . . . . . . . . . . . . 10

High Voltage Check . . . . . . . . . . . . . . . 10

Purity Convergence Procedure . . . . . . . . . . . .11

Vertical Raster Shift Adjustment. . . . . . .11

Initial Center Static Convergence . . . . . .11

Purity Adjustment . . . . . . . . . . . . . . . . . 12

Final Convergence Procedure . . . . . . . 12

Permalloy Convergence

Corrector Strip . . . . . . . . . . . . . . . . 12

Service Mode

(Electronic Controls). . . . . . . . . . . . . . . . . 14

Instructional Flow Chart

for Service Mode . . . . . . . . . . . . . . . . . . . . 20

Focus (Part of T551). . . . . . . . . . . . . . . 25

Component Identification . . . . . . . . . . . . . . . . 26

Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Components Abbreviations Guide. . . . . . . . . 35

Schematic Notes . . . . . . . . . . . . . . . . . . . . . . . 36

Service Mode Adjustments. . . . . . . . . . . . . . . 47

C-Board Schematic . . . . . . . . . . . . . . . . . . . . . 39

C-Board Voltages. . . . . . . . . . . . . . . . . . . . . . . 39

A-Board Schematics

CT-25G6/CE/UE. . . . . . . . . . . . . . . . . . . 40

CT-27G6E/CE/UE) . . . . . . . . . . . . . . . . . 42

SP-2724E/UE . . . . . . . . . . . . . . . . . . . . . 42

A-Board Voltages. . . . . . . . . . . . . . . . . . . . . . . 44

Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

A & C-Boards Layouts. . . . . . . . . . . . . . . . . . . 46

- 3 -

Service Notes

Chip Components

Note: Some components may be affixed wi th glue. B e careful not to bre ak or damag e foil un der the com ponent

or at the pins of th e ICs when removing . Usually applying he at to the component for a short time while twisting with tweezers will break the component loose.

Leadless Chip Component (surface mount)

Chip components must be replaced with identical chips due to critical foil tr ack spacing. There are n o holes in the board to mount standard transistors or diodes. Some chips capacitor or resistor board solder pads may have holes t hrough the board, however the hole diameter limits standard resistor replacement to 1/8 watt. Standard capacitor may also be limited for the same reason. It is recommended that identical components be used. Chip resistor have a three digit numerical resistance code - 1st and 2nd significant digits and a multiplier. Example: 162 = 1600 or 1.6kΩ resistor, 0 = 0Ω (jumper). Chip capacitors generally do not have the value indicated on the capacitor. The color of the co mponent indicates the general range of the capaci tance. Chip transistors are id enti fie d b y a two letter code. The first letter indicates the type and the second lette r, the grade of transistor. Chip diodes have a two lette r i den tif icati on c ode as per the code chart an d are a dual diode pack with either common anode or common cathode. Check the parts list for correct diode number.

Component Removal

1. Use solder wick to remove s older from compo nent end caps or terminal.

2. Without pulling up, carefully twist the component with tweezers to break the adhesive.

3. Do not reuse removed leadless or chip components since they are subject to stress fracture during removal.

Chip Component Installation

1. Put a small amount of solder on the board soldering pads.

2. Hold the chip component against the soldering pads with tweezers or with a miniature alligator clip and apply heat to the pad area with a 30 watt iron until solder flows. Do not appl y heat for more than 3 seconds.

How to Replace Flat-IC

- Required Tools -

• Soldering iron • De-solder braids

• Needle nose pliers • Magnifier

• Wire cutters (sharp & small)

1. Cut the pins of a defective IC with wire cutters. Remove IC from boar d. If IC i s glued to the board , heat the IC and release the IC. See Note above.

Flat IC

2. Using soldering iron and needle nose pliers remove the IC pins from the board.

Soldering Iron

3. Using de-soldering braid and soldering iron remove solder from affected are on board (pads).

De-soldering Braid

Soldering Iron

4. Position the new Flat-I C in place (app ly the pins of the Flat-IC to the soldering pads where the pins need to be soldered). Determine the positions of the soldering pads and pins by correctly aligning the polarity symbol. Solder pin #1 first, align the IC.

Polarity symbol

Solder the pin op posite to pin #1. This will ass ist positioning the IC.

5. Solder all pins to the soldering pads using a fine tipped soldering iron.

2nd solder

1st solder

Solder

6. Check with a magnifier for solder bridge between the pins or for d r y jo int b etwe en pi ns a nd s old er in g pads. To remove a solder bridge, u se a de-solder braid as shown in the figure below.

- 4 -

Soldering Iron

IMPORTANT: To protect against possible damage to the solid state devices due to arcing or static discharge, make certain that all ground wires and CRT DAG wire are securely connected.

CAUTION: The power supply circuit is above earth ground and the chassis cannot be polarized. Use an isolation transformer when servicing the Receiver to avoid damage to the test equipmen t or to the chassis. Connect the test equipment to the proper ground ( ) or

( ) when servicing, or incorrect voltages will be measured.

WARNING: This Receiver has been designed to meet or exceed applicable safety and X-ray radiation protection as specified by government agencies and independent testing laboratories.

To maintain original product safety design standards relative to X-ray radiation and shock and fire hazard,

parts indicated with the s ymbol on the schematic must be replaced with identical parts. Order parts from

the manufacturer’s parts center using the parts numbers shown in t his service manual, or provide the chassis number and the part reference number.

For optimum perfo rmance and reliab ility, all other parts should be replaced with components of identical specification.

X-Ray Protection Circuit Check & Adjustments

This test must be perfo rmed as final check be fore the Receiver is returned to the customer. If voltages are out of tolerance, immediate service and correction is required to insure safe operation and to prevent the possibility of premature component failure.

Equipment:

1. Isolation transformer.

2. High voltage meter.

3. Short jumper.

4. Jumper di od e ( s am e a s D82 3, PN S3L60P154004 ) . Diode should be rated a minimum of 150V.

Procedure:

1. Connect the Receiver to an isolation transformer. Turn Receiver ON.

2. Apply a monoscope pattern.

3. In Service Mode (see S ervi ce Mod e Sect ion in th is manual) select register Cb.

4. Measure TP5 (located near the tuner). Compare the measured value to the left column of the table below. Set Cb with value from the right column corresponding to the measured level at TP5. Example, if the measured level at TP5 is 1.03V , set Cb to 03.

TP5 MEASUREMENT SET Cb TO (HEX)

0 ~ 0.93V 00

0.93 ~ 0.97V 01

0.97 ~ 1.01V 02

1.01 ~ 1.05V 03

1.05 ~ 1.09V 04

1.09 ~ 1.13V 05

1.13 ~ 1.17V 06

1.17 ~ 1.21V 07

5. Exit Service Mode and shut it OFF.

6. Connect the short jumper between TPD16 and TPD17.

7. Connect the jumper diode between TPD14 and TPD15 (cathode connected to TPD14, anode connected to TPD15, See Fig. 4 for locations).

8. Apply 75VAC to the input of the isolation transformer.

9. Turn Receiver ON.

10. Set PICTURE and BRIGHTNESS to minimum.

11. Slowly increase the voltage at the input of the isolation transformer and confirm HHS voltage measure 35.0KV for 25” models, 35.8KV for 27”

models using SAMSUNG CRT or 35.0KV for 27” models using AMEC CRT when the Receiver starts

to go out of sync.

12. Turn Receiver OFF and remove jumper & diode.

- 5 -

Receiver Feature Table

FEATURE\MODEL CT-25G6E/CE/UE CT-27G6E/DE/UE SP-2724E/UE

Chassis AP361 AP362 EC363 Tuning system 40K 40K 40K # of channels 181 181 181 Menu language Eng/Span/Fr Eng/Span/Fr Eng/Span/Fr Closed Caption XXX V-Chip XXX 75 Ω input XXX FM radio XN/AN/A Remote Model # EUR501455 EUR501450 EUR511514 Picture tube A63QDB891X A68QDN891X M68LGL061X Panablack Tube XXX Comb Filter 2 Line Digital 2 Line Digital 2 Line Digital V/A norm VVV MTS/SAP/DBX XXX AI Sound XXX Built-in audio power 1.5W x 2 (10%) 1.5W x 2 (10%) 1.5W x 2 (10%) # of speakers 222 A/V in (rear/front) 1 (1 / 1) 1 (1 / 0) 1 (1 / 0) S-VHS input (rear/front) N/A 1/0 1/0 Headphone Jack XXN/A Dimensions mm

(WxDxH) in Weight (kg/lbs) 29 / 63.8 35 / 77.2 35 / 77.2 Power source (V/Hz) 120 / 60 120 / 60 120 / 60 Anode voltage 29.25kV ± 1.25kV 29.25kV ± 1.25kV 29.25kV ± 1.25kV Video input jack Audio input jack 500mV RMS 47kΩ 500mV RMS 47kΩ 500mV RMS 47kΩ A-Board TNP2AH024 CB* BB* BH* C-Board TNP2AA075 AC* AB* AG*

633.4 x 491.8 x 568

24.9 x 19.4 x 22.4

75Ω, phono jack 1V

p-p

665.2 x 545 x 594.8

26.2 x 21.5 x 23.4

75Ω, phono jack 1V

p-p

731 x 684 x 614

28.8 x 26.9 x 24.2

75Ω, phono jack

p-p

Table 1. Receiver Features

Specifications are subject to change without notice or obligation. Dimensions and weights are approximate.

* Note: When ordering a replacement board assembly,

append an “S” to the board number. Example: to order the A-Board for CT-27G6E, the replacement board is TNP2AH024BBS.

- 6 -

Location of Receiver Controls

4 5

Remote Control

Sensor

Front A/V Input

(Available on

some models)

Figure 2. Location of Controls (Quasar models displayed, Panasonic models vary).

Quick Reference

Control Operation

Power Button - Press to turn ON or OFF. Volu me B uttons - Press to adjust Sound Level, or to adjust Audio Menus, Video

Menus, and select operating features when menus are displayed Channel Buttons - Press to select programmed chan nels. Press to highlight des ired

features when menus are dis played. Also use to s elect Cable Conver ter box c hannel s

after programming R emote Control Infra-red code s (the TV/AUX/CABLE swi tch must be set in CABLE position).

Action Button - Press to display Main Menu and access On Screen feature and

Adjustment Menus.

TV/Video Button - Press to select TV or Video Input.

- 7 -

Location of Controls

POWER Press to turn ON and OFF.

TV/VIDEO Press to select TV or Video

Mode.

VOL Press to adjust TV sound and

navigate in menus.

MUTE Press to mute sound. Press to

access and cancel (CC) Closed Caption.

“0”~ “9” Press numeric keypad to select

any channel.

R-TUNE Press to switch to previously

viewed channel or video mode.

TV, VCR, DBS/CBL, DVD Press to select remote

operation.

EXIT/GUIDE DBS function buttons.

CH Press to select next channel

and navigate in menus.

ACTION Press to access menus.

RECALL Press to display time, channel,

sleep timer, and other options.

REW, PLAY, FF, TV/VCR, STOP, PAUSE, REC, VCR/DBS CH

Component function buttons.

EUR511514

(Typical)

Figure 3. Location of Controls (Quasar models, Panasonic remotes vary).

- 8 -

Disassembly for Service

Back Cover

Remove all the screws marked with an arrow( ) from the back of the Receiver.

Note: Screw configuration, type, and number of

screws vary depending on the model of the Receiver serviced; various models are covered in this Manual. Reuse hardware when reassembling the Receiver.

• 3 screws at the top edge of the Receiver.

• 1 screw at each lower corner of the Receiver.

• 1 screw by the AC cord assembly.

• 1 screw by the A/V jacks.

• 1 screw by the Flyback assembly.

A-Board - Main Chassis

1. Slide the chassis completely out of the guide rails.

2. Stand the Receiver on its edge. The undersi de of the board is completely accessible for component replacement.

Note: Some tie-wraps t hat secure the wire d ressings

may need to be unfastened for chassis removal.

C-Board - CRT Output

The board plugs onto the socket on the CRT neck. To release the Focus wire, use a dull object to release the tab on the socket (near the wire opening) and carefully pu ll on the wi re. To connect the Focus wire, press on the tab to lock it then insert the wire in the opening and press on it until it is fully inserted and locked in place.

Speakers

Each speaker is secured to the cabinet’s front with 2 screws.

Keyboard Push Button Assembly

Fastened with screws to the inside of the cabinet front.

Disassembly for CRT Replacement

1. Discharge the CRT as instructed in the Safety Precautions (see page 2).

2. Disconnect the yoke (DY) plug, degaussing coil (DEG) plug from the main board.

3. Unplug the CRT 2nd anode button from the main board.

4. Remove the C-Board from the CRT base and unplug the black wire (CRT dag ground) C10.

5. Disconnect the A11, A12, and Speakers plugs from the A-Board.

6. Lift the Main Chassis (A-Board) and all mounted boards complet ely o ut w ith th e CR T Bo ard a tt ached .

CRT Replacement

1. Perform Disassembly for CRT Replacement procedure.

2. Insure that the CRT H.V. Anode button is discharged before handling the CRT. Read the Safety Precautions (see page 2 on handling the picture tube.)

3. Remove the components from the CRT neck an d place the cabinet face down on a soft pad.

4. Note the original order for the CRT mounting hardware as they are remove from the CRT mounting brackets at each corner of the CRT.

5. Remove the CRT with the deg aussing coil and th e dag ground braid attached.

6. Note the original locations and mounting of the degaussing coil and the dag ground assembly to insure proper reinstallation on the replacement CRT. To remove and re-mount the degaussing coil: The degaussing coil is held in place by clampers fastened to the CRT corner ears. These clampers must be installed onto th e replacement CRT prior to mounting the degaussing coil.

To remove and re-mount the dag ground braid:

a. Unhook the coil spring from the bottom corners

of the CRT ears.

b. Releas e the braid loop from the upper corne rs

of the CRT ears.

7. Mount the dag ground braid on the replacement CRT. Position the degaussing coil with new ties. Dress coil as was on the original CRT.

8. Replace the components on CRT neck and reinstall into cabinet. Verify that all ground wires and circuit board plugs get connected.

- 9 -

Chassis Service Adjustment Procedures

All service adjustm ents are factory preset and should not require adjustment unless controls and/or associated components are replaced.

Figure 4. A-Board Main

Components and Test Points

(Components within dotted

areas are located on

trace side)

Note: Connect the (-) lead of the voltmeter to the

appropriate ground. Use IC801’s heat sink when the HOT ground symbol ( ) is used.

Otherwise, use COLD ground ( ) — Tuner shield, IC451’s heat sink or FA2.

MOMENTARILY CONNECT A JUMPER TO ENTER SERVICE MODE (FA1 to FA2)

130.0V B+ Voltage Confirmation

1. Set the Bright and the Contrast to Minimum by using the Picture Menu.

2. Connect the DVM between C825 (+ side) or TPD14 and cold ground ( ).

3. Confirm that B+ voltage is 130.0V ± 2.5V. This voltage supplies B+ to the Horizontal Output & Flyback circuits.

Source Voltage Chart

120V AC line input. Se t the Bright and the Picture to Minimum by using th e Picture Menu. Use cold ground

(

) for the (-) lead of the DVM.

LOCATION VOLTAGE

TPD8 26.0V ± 2.0V TPD9 13.0V ± 2.0V IC551 Pin3 9.0V ± 0.25V IC552 Pin3 5.0V ± 0.25V D554 Cathode 220V ± 15V

Adjust Picture Menu for normalized video adjustments.

High Voltage Check

1. Select an active TV channel and confirm that horizont al is in sync.

2. Adjust Brightne ss and Contrast using P icture Icon menu so video just disappears.

3. Confirm B+ 131V is within limit.

4. Using a high voltage meter confirm that the High Voltage is 29.25kV ± 1.25kV.

- 10 -

Purity and Convergence Procedure

Adjustment is necessary only if the CRT or the deflection yoke is replaced or if the setting was disturbed. The complete procedure consists of:

1. Vertical Raster Shift Adjustment. (Only for Models

with Purity/Convergence Assembly with 4 Pairs of Rings).

2. Initial static convergence.

3. Setting the purity.

4. Final static convergence.

results, note part numb er and look fo r specif ications a t Service Center)

When the CRT or the Yoke is Replaced

Place the yoke on the CRT neck (do not tighten the clamp).

For a 2-piece assembly (see Fig. 5):

Position purity/convergence assembly as shown and tighten clamp snugly. Remove the hot-melt glue seal on assembly and position like tabs of purity device

together at 12 o’clock to reduce its magnetic field effect.

Figure 5. Posi tionin g o f Pur ity/Con ve rgence As semb ly

(2-piece assembly)

For models using 4 pairs of rings, place the vertical

raster shift tabs at 3 o’clock (90 convergence tabs, see Fig. 6 and Fig. 7)

from the purity and

Figure 8. Positioning of Purity/Convergence

Assembly (1-pi ece assembly)

For either assemblies: Turn the Receiver ON. Operate the Receiver for 60 minutes using the first Purity Check field (white screen) to stabilize the CRT.

Fully degauss the Receiver by using an external degaussing coil.

Slide the defle ction y oke back and forth o n t he ne ck o f the CRT until it produces a near white, uniform raster.

Vertical Raster Shift Adjustment (Only for

Models with Purity/Convergence Assembly with 4 Pairs of Rings).

Apply a green pattern with a horizontal line, adjus t the Deflection Yoke so that has no tilt, then secure it. Adjust center line of the pattern with the mechanical center of the CRT, this center is determined by two marks at the side edges of the screen. To adjust the line, once the vertical raster shift tabs are place at 3 o’clock to reduce its magnetic field effect (see Fig. 6 and Fig. 7) open the tabs the same angle from the center, until the center line of the pattern becomes a straight line, center ed with the marks of the CRT. (see Fig. 9.)

Figure 6. Positioning of Purity/Convergence

Assembly (4 Pairs of Rings)

Figure 7. Positioning of Purity/Convergence

Assembly (4 Pairs of Rings)

For a 1-piece assembly (see Fig.8):

Position like tabs of purity devices together at 12

o’clock to reduce any ma gnetic field effect. (For be tter

Figure 9. Vertic a l R a s t e r S hift Adjustmen t

(4 pairs of rings assembly)

Initial Center Static Convergence

Connect a dot/cross hatch generator to the Receiver and tune in a signal. Observe misconvergence at center of the screen only. Adjust the R & B pole magne ts; by se parating tab s an d rotating to converge blue with red. Adjust the R & B and R & B & G pole magnets: by separating tabs and rotating to converge blue an d red (magenta) with green.

Note: Precise convergence at this point is

not important.

- 11 -

Purity Adjustment

Figure 10. Green Raster Adjustment

When the Receiver is in the Service Mode fo r making electronic adjustments, press the Rec all button on the Remote Control to enter Purity Check. (See the Service Adjustments Electronic Controls procedure). Operate the Receiver for 60 minutes using the first Purity Check field (white screen) to stabilize the CRT. Fully degauss the Receiver by using an external degaussing coil. Press the Recall button on the Remote Control again until the Purity Check (green screen) appears.

For a 2-piece assembl y (see Fig. 5):

Loosen the deflection yok e clamp screw an d move the deflection yoke bac k as close to the purity magnet as possible. Adjust the Purity r ings to set the vertical green ra ster precisely at the center of the screen (see Fig. 10).

Slowly move the deflecti on yoke forward until the bes t overall green screen is displayed.

Final Convergence Procedure (see Fig. 11

through Fig. 13)

Note: Vertical size and focus adjustments must be

completed prior to performing the convergence adjustment. Connect a dot pattern generator to the Receiver. The Brightness level should not be higher than necessary to obtain a clear pattern.

Converge the red and the blue dots at the center of the screen by rotating the R & B pole Static Convergence Magnets. Align The conver ged red/blue do ts with the green dots at the center of the scree n by rotating the R & B & G pole Static Convergence Magnets. Melt wax with soldering iron to reseal the magnets. Slightly tilt vertica lly and ho rizo ntally (do no t rotate) th e deflection yoke to obtain a good overall convergence. If convergence is not reached at the edges, insert permalloy (see fo llowing section) from the DY corners to achieve proper convergence. Recheck for purity and readjust if necessary. After vertical adjustment of the yoke, insert wedge at 11

o’clock position, then make the horizontal tilt adjustment. Secure the deflection yoke by inserting two side wedges at 3 and 7 o’clock positions. Apply adhesive between tab (thin portion) of wedge and CRT and place tape over the tab to sec ure to the CRT.

For a 1-piece assembl y (see Fig. 8):

Slowly move the deflection yoke and purity rings assembly toward the CRT board and adju st the purity magnet rings to set vertical green raster at center of screen (see Fig. 10). Gradually move the deflection yoke & purity rings forward and adjust for best overall green screen.

Continue from here for either assemblies:

Tighten the deflection yoke clamp screw. Press the Recall button on the Remote Control again until the purity check (blue screen) and (red screen) appear and observe that good purity is obtained on each respective field. Press the Recall button on the Remote Control again until Purity check (white s creen) appear s. Observe th e screen for uniform white. If purity has not been achieved, repeat the above procedure.

Permalloy Convergence Corrector St rip (Part No. 0FMK014ZZ)

This strip is used in some sets to match the yo ke and CRT for optimum convergence. If t he yoke or CRT is replaced, the strip may not be required. First converge the set without the strip and observe the corners.

If correction is needed:

1. Place strip between CRT and yoke, in quadrant needing correction. Slowly move it around for desired results.

2. Press adhesive tightly to the CRT and secure with tape.

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Figure 11. Vertical Yoke Movement

Figure 12. Horizontal Yoke Movement

Figure 13. Convergence Magnets and Wedges Location

Note: For models using 4 pairs of rings

assemblies see Fig. 6 for details

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Service Mode (Electronic Controls)

This Receiver has electronic technology usi ng the I²C Bus Concept. It performs as a control function and it replaces many mechanical controls. Instead of adjusting mechanical controls indivi dually, many of the control functions are now performed by using “On Screen Display Menu”. (The Service Adjustment

Mode.)

Note: It is sug geste d that the tec hnician r eads al l the

way through and understand the following procedure for Entering/Exiting the Service Adjustment Mode; then proceed with the instructions working with the Receiver. When becoming familiar with the procedure, the Flow Chart for Service Mode may be used as a quick guide.

Quick Entry to Service Mode:

At times when minor adjustments need to be done to the electronic controls, the method of Entering the service Mode without rem ov al of the ca bin e t ba ck is as follows using the Remote Control:

1. Adjust VOLUME to minimum (0).

2. Set CC Mode (Close Caption) OFF.

3. Select SET-UP icon and select CABLE mode.

4. Select TIMER icon and set S LEEP time for 30, 60 or 90 Min.

5. Press ACTION button twice to exit menus.

6. Tune to the Channel 124.

7. Press the VOL button (decrease) on Receiver. Red “CHK” appears in the left upper corner.

B 00 33

An address Menu appears in the right hand corner of the screen

C 00 0 255

Figure 14. Service Mode Menu Adjustments.

Note: Only the applicable settings for the Receiver

serviced will be available (See a in Fig. 14).

Exiting the Service Mode:

Press the Action and the Power buttons on the Receiver simultaneously for at least 2 seconds.

THE RECEIVER EXITS SERVICE MODE

The Receiver momentarily shuts off; then comes back on tuned to channel 3 with a preset level of sound. Any programmed c hannel s, ch annels capt ion data an d some others user defined settings will be erased.

IMPORTANT

Always Exit the Service Mode

Following Adjustments.

To toggle between Aging and Service modes:

While the “CHK” is displayed on the left top corner of the CRT, pressing the Action and the Volume Up buttons on the Receiver simultaneously will toggle between the modes. Red “CHK” for Service and yellow “CHK” for Aging.

Note: Three additional indic ators appear on screen.

One is the five digit usage in hours and the other two are four digits for V-Chip Main and Child ratings. Indicators are hexadecimal numbers.

8. Press the Power Button on the Remote Control to select one of seven Service Adjustment Modes.

1. B= Service VCJ SUB-DATA adjustments.

2. C= Service VCJ CUT-OFF adjustments.

3. M= Service MTS adjustments.

4. P= Service VCJ adjustments.

5. S= Service OPTIONS (PICTURE) adjustments.

6. X = Service AFC adjustments.

7. “CHK” = Normal operation of CHANNEL and

VOLUME .

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Press the POWER Button on the Remote Control to select the Service Adjustment.

For Adjustments:

1.Press Channel Up/Down on the Remote Control to select one of

the available Ser vice Adjustments (a in Fig. 14).

Note: Write Down the original

value set (b in

Fig. 14

) for each address before modifying anything. It is easy to erroneously adjust the wrong item.

2.Press Volume Up/Down on the Remote Control to adjust the level of the selected Service Adjustment (b in Fig. 14).

Sub-Data Adjustment

B0 SUB-COLOR 33 B1 SUB-TINT 36 B2 SUB-BRIGHTNESS 127 B3 SUB-CONTRAST 20 B4 R OFFSET-factory preset 0 B5 YNR-factory preset 0 B6 YNR LIM-factory preset 0

Cut-Off Adjustment

C0 CUT-OFF R 0 255 C1 CUT-OFF G 0 255 C2 CUT-OFF B 0 255 C3 R DRIVE 80 C4 G DRIVE 80

Default

Level

Default

Level

C5 B DRIVE 80 C6 V-SIZE 127 C7 NOT USED -C8 NOT USED --

C9 H CENTER 16 CA ACL 1 CB HHS 0 CC OSD SHIFT-factory preset 88 CD A CL-R EF-fa cto r y pres et 74 CE ACL-REF-fa cto ry pres et 64 CF ACL-REF-factory pres et 48

C10 ACL-REF-factory preset 40

C11 ACL-REF-factory pres et 31 C12 ACL-REF-factory preset 20 C13 ACL-COEF-factory preset 124 C14 ACL-COEF-factory preset 117

Note: Registers noted

with “factory preset” should not be modified.

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