Magnavox 20MC4304/17 Service Manual

Contents

Chapter

Sec. 1: Adjustment Procedures

Schematic Diagrams and CBA's Exploded Views Mechanical and Electrical Parts Lists

Sec. 2: Standard Maintenance

Mechanism Alignment Procedures Disassembly / Assembly of Mechanism Deck Exploded Views Deck Parts List

Survey of versions:

Published by FU-KC 0517 Service AV Systems Printed in The Netherlands Subject to modification

/17 NTSC

Color TV with Built-In VCR/DVD Player 20MC4304/17

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, or otherwise without the prior permission of Philips.

EN 3139 785 31060

CLASS 1 LASER PRODUCT KLASSE 1 LASER PRODUKT KLASS 1 LASER APPARAT CLASSE 1 PRODUIT LASER

Service Manual

Service Service

Service

This service manual is for 20MC4304/17 Third Generation model, which is different from the previous generation 20MC4304/17 models.

For Third Generation model, the serial number begins with DD2Bxxxxxxxxxx.

Refer to the rating label illustration at right.

MARCH 2005 V x x x x

DD2Bxxxxxxxxxx

Serial number

Rating label

MAIN SECTION

Color TV with Built-In

VCR/DVD Player

TABLE OF CONTENTS

LASER BEAM SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1-1

IMPORTANT SAFETY PRECAUTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2-1

STANDARD NOTES FOR SERVICING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3-1

PREPARATION FOR SERVICING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4-1

OPERATING CONTROLS AND FUNCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5-1

CABINET DISASSEMBLY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6-1

ELECTRICAL ADJUSTMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7-1

HOW TO INITIALIZE THE TV/DVD/VCR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8-1

FIRMWARE RENEWAL MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9-1

BLOCK DIAGRAMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10-1

SCHEMATIC DIAGRAMS / CBA’S AND TEST POINTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-1

WAVEFORMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12-1

WIRING DIAGRAM < TV/VCR SECTION >. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13-1

WIRING DIAGRAM < DVD SECTION >. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13-2

SYSTEM CONTROL TIMING CHARTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14-1

IC PIN FUNCTION DESCRIPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15-1

LEAD IDENTIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16-1

ELECTRICAL PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17-1

EXPLODED VIEWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18-1

MECHANICAL PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19-1

Sec. 1: Main Section

I Adjustment Procedures I Schematic Diagrams and CBA’s I Exploded Views I Mechanical and Electrical Parts List

Manufactured under license from Dolby Laboratories. “Dolby” and the double-D symbol are trademarks of Dolby Laboratories.

1-1-1 E6NLSP

LASER BEAM SAFETY PRECAUTIONS

This DVD player uses a pickup that emits a laser beam.

The laser beam is emitted from the location shown in the figure. When checking the laser diode, be sure to keep your eyes at least 30 cm away from the pickup lens when the diode is turned on. Do not look directly at the laser beam.

CAUTION: Use of controls and adjustments, or doing procedures other than those specified herein, may result in hazardous radiation exposure.

Location: Top of DVD mechanism.

Do not look directly at the laser beam coming from the pickup or allow it to strike against your skin.

Drive Mechanism Assembly

Laser Beam Radiation

Laser Pickup

Turntable

LASER RADIATION

WHEN OPEN. DO NOT

STARE INTO BEAM.

CAUTION

1-2-1 T1102_ISP

IMPORTANT SAFETY PRECAUTIONS

Prior to shipment from the factory, our products are strictly inspected for recognized product safety and electrical codes of the countries in which they are to be sold. However, in order to maintain such compliance, it is equally important to implement the following precautions when a set is being serviced.

Safety Precautions for TV Circuit

1. Before returning an instrument to the customer, always make a safety check of the

entire instrument, including, but not limited to, the following items:

a. Be sure that no built-in protective devices are

defective and have been defeated during servicing. (1) Protective shields are provided on this chassis to protect both the technician and the customer. Correctly replace all missing protective shields, including any removed for servicing convenience. (2) When reinstalling the chassis and/or other assembly in the cabinet, be sure to put back in place all protective devices, including but not limited to, nonmetallic control knobs, insulating fishpapers, adjustment and compartment covers/shields, and isolation resistor/capacitor networks. Do not operate this instrument or

permit it to be operated without all protective devices correctly installed and functioning. Servicers who defeat safety features or fail to perform safety checks may be liable for any resulting damage.

b. Be sure that there are no cabinet openings

through which an adult or child might be able to insert their fingers and contact a hazardous voltage. Such openings include, but are not limited to, (1) spacing between the picture tube and the cabinet mask, (2) excessively wide cabinet ventilation slots, and (3) an improperly fitted and/or incorrectly secured cabinet back cover.

c. Antenna Cold Check - With the instrument AC

plug removed from any AC source, connect an electrical jumper across the two AC plug prongs. Place the instrument AC switch in the on position. Connect one lead of an ohmmeter to the AC plug prongs tied together and touch the other ohmmeter lead in turn to each tuner antenna input exposed terminal screw and, if applicable, to the coaxial connector. If the measured resistance is less than 1.0 megohm or greater than 5.2 megohm, an abnormality exists that must be corrected before the instrument is returned to the customer. Repeat this test with the instrument AC switch in the off position.

d. Leakage Current Hot Check - With the

instrument completely reassembled, plug the AC line cord directly into a 120 V AC outlet. (Do not use an isolation transformer during this test.) Use a leakage current tester or a metering system that complies with American National Standards Institute (ANSI) C101.1

Leakage Current for Appliances and Underwriters Laboratories (UL) 1410, (50.7). With the instrument AC switch first in the on position and then in the off position, measure from a known earth ground (metal water pipe, conduit, etc.) to all exposed metal parts of the instrument (antennas, handle brackets, metal cabinet, screw heads, metallic overlays, control shafts, etc.), especially any exposed metal parts that offer an electrical return path to the chassis. Any current measured must not exceed 0.5 milli-ampere. Reverse the instrument power cord plug in the outlet and repeat the test.

ANY MEASUREMENTS NOT WITHIN THE LIMITS SPECIFIED HEREIN INDICATE A POTENTIAL SHOCK HAZARD THAT MUST BE ELIMINATED BEFORE RETURNING THE INSTRUMENT TO THE CUSTOMER OR BEFORE CONNECTING THE ANTENNA OR ACCESSORIES.

e. X-Radiation and High Voltage Limits -

Because the picture tube is the primary potential source of X-radiation in solid-state TV receivers, it is specially constructed to prohibit X-radiation emissions. For continued Xradiation protection, the replacement picture tube must be the same type as the original. Also, because the picture tube shields and mounting hardware perform an X-radiation protection function, they must be correctly in place. High voltage must be measured each time servicing is performed that involves B+, horizontal deflection or high voltage. Correct operation of the X-radiation protection circuits also must be reconfirmed each time they are serviced. (X-radiation protection circuits also

ALSO TEST WITH PLUG REVERSED USING AC ADAPTER PLUG AS REQUIRED

TEST ALL EXPOSED METAL SURFACES

READING SHOULD NOT BE ABOVE 0.5 mA

EARTH GROUND

DEVICE

LEAKAGE

CURRENT

TESTER

BEING

TESTED

1-2-2 T1102_ISP

may be called “horizontal disable” or “hold down.”) Read and apply the high voltage limits and, if the chassis is so equipped, the Xradiation protection circuit specifications given on instrument labels and in the Product Safety & X-Radiation Warning note on the service data chassis schematic. High voltage is maintained within specified limits by close tolerance safety-related components/ adjustments in the high-voltage circuit. If high voltage exceeds specified limits, check each component specified on the chassis schematic and take corrective action.

2. Read and comply with all caution and safetyrelated notes on or inside the receiver cabinet, on the receiver chassis, or on the picture tube.

3. Design Alteration Warning - Do not alter or add to the mechanical or electrical design of this TV receiver. Design alterations and additions, including, but not limited to circuit modifications and the addition of items such as auxiliary audio and/or video output connections, might alter the safety characteristics of this receiver and create a hazard to the user. Any design alterations or additions will void the manufacturer's warranty and may make you, the servicer, responsible for personal injury or property damage resulting therefrom.

4. Picture Tube Implosion Protection Warning - The picture tube in this receiver employs integral implosion protection. For continued implosion protection, replace the picture tube only with one of the same type number. Do not remove, install, or otherwise handle the picture tube in any manner without first putting on shatterproof goggles equipped with side shields. People not so equipped must be kept safely away while picture tubes are handled. Keep the picture tube away from your body. Do not handle the picture tube by its neck. Some “in-line” picture tubes are equipped with a permanently attached deflection yoke; because of potential hazard, do not try to remove such “permanently attached” yokes from the picture tube.

5. Hot Chassis Warning -

a. Some TV receiver chassis are electrically

connected directly to one conductor of the AC power cord and maybe safety-serviced without an isolation transformer only if the AC power plug is inserted so that the chassis is connected to the ground side of the AC power source. To confirm that the AC power plug is inserted correctly, with an AC voltmeter, measure between the chassis and a known earth ground. If a voltage reading in excess of

1.0V is obtained, remove and reinsert the AC power plug in the opposite polarity and again measure the voltage potential between the chassis and a known earth ground.

b. Some TV receiver chassis normally have 85V

AC(RMS) between chassis and earth ground

regardless of the AC plug polarity. This chassis can be safety-serviced only with an isolation transformer inserted in the power line between the receiver and the AC power source, for both personnel and test equipment protection.

c. Some TV receiver chassis have a secondary

ground system in addition to the main chassis ground. This secondary ground system is not isolated from the AC power line. The two ground systems are electrically separated by insulation material that must not be defeated or altered.

6. Observe original lead dress. Take extra care to assure correct lead dress in the following areas: a. near sharp edges, b. near thermally hot parts-be sure that leads and components do not touch thermally hot parts, c. the AC supply, d. high voltage, and, e. antenna wiring. Always inspect in all areas for pinched, out of place, or frayed wiring. Check AC power cord for damage.

7. Components, parts, and/or wiring that appear to have overheated or are otherwise damaged should be replaced with components, parts, or wiring that meet original specifications. Additionally, determine the cause of overheating and/or damage and, if necessary, take corrective action to remove any potential safety hazard.

8. Product Safety Notice - Some electrical and mechanical parts have special safety-related characteristics which are often not evident from visual inspection, nor can the protection they give necessarily be obtained by replacing them with components rated for higher voltage, wattage, etc.. Parts that have special safety characteristics are identified by a # on schematics and in parts lists. Use of a substitute replacement that does not have the same safety characteristics as the recommended replacement part might create shock, fire, and/or other hazards. The product's safety is under review continuously and new instructions are issued whenever appropriate. Prior to shipment from the factory, our products are strictly inspected to confirm they comply with the recognized product safety and electrical codes of the countries in which they are to be sold. However, in order to maintain such compliance, it is equally important to implement the following precautions when a set is being serviced.

1-2-3 T1102_ISP

Precautions during Servicing

A. Parts identified by the # symbol are critical for

safety. Replace only with part number specified.

B. In addition to safety, other parts and assemblies

are specified for conformance with regulations applying to spurious radiation. These must also be replaced only with specified replacements. Examples: RF converters, RF cables, noise blocking capacitors, and noise blocking filters, etc.

C. Use specified internal wiring. Note especially:

1) Wires covered with PVC tubing

2) Double insulated wires

3) High voltage leads

D. Use specified insulating materials for hazardous

live parts. Note especially:

1) Insulation Tape

2) PVC tubing

3) Spacers

4) Insulators for transistors.

E. When replacing AC primary side components

(transformers, power cord, etc.), wrap ends of wires securely about the terminals before soldering.

F. Observe that the wires do not contact heat

producing parts (heat sinks, oxide metal film resistors, fusible resistors, etc.)

G. Check that replaced wires do not contact sharp

edged or pointed parts.

H. When a power cord has been replaced, check that

5~6 kg of force in any direction will not loosen it.

I. Also check areas surrounding repaired locations.

J. Be careful that foreign objects (screws, solder

droplets, etc.) do not remain inside the set.

K. Crimp type wire connector

When replacing the power transformer in sets where the connections between the power cord and power transformer primary lead wires are performed using crimp type connectors, in order to prevent shock hazards, perform carefully and precisely the following steps. Replacement procedure

1) Remove the old connector by cutting the wires at a point close to the connector. Important: Do not re-use a connector (discard it).

2) Strip about 15 mm of the insulation from the ends of the wires. If the wires are stranded, twist the strands to avoid frayed conductors.

3) Align the lengths of the wires to be connected. Insert the wires fully into the connector.

4) Use the crimping tool to crimp the metal sleeve at the center position. Be sure to crimp fully to the complete closure of the tool.

L. When connecting or disconnecting the DVD/VCR

connectors, first, disconnect the AC plug from the AC supply socket.

1-2-4 T1102_ISP

Safety Check after Servicing

Examine the area surrounding the repaired location for damage or deterioration. Observe that screws, parts and wires have been returned to original positions. Afterwards, perform the following tests and confirm the specified values in order to verify compliance with safety standards.

1. Clearance Distance

When replacing primary circuit components, confirm specified clearance distance (d) and (d') between soldered terminals, and between terminals and surrounding metallic parts. (See Fig. 1)

Table 1: Ratings for selected area

Note: This table is unofficial and for reference only. Be

sure to confirm the precise values.

2. Leakage Current Test

Confirm the specified (or lower) leakage current between B (earth ground, power cord plug prongs) and externally exposed accessible parts (RF terminals, antenna terminals, video and audio input and output terminals, microphone jacks, earphone jacks, etc.).

Measuring Method: (Power ON)

Insert load Z between B (earth ground, power cord plug prongs) and exposed accessible parts. Use an AC voltmeter to measure across both terminals of load Z. See Fig. 2 and following table.

Table 2: Leakage current ratings for selected areas

Note: This table is unofficial and for reference only. Be sure to confirm the precise values.

AC Line Voltage Region

Clearance

Distance (d), (d’)

110 to 130 V

U.S.A. or

Canada

≥ 3.2 mm

(0.126 inches)

AC Line Voltage Region Load Z Leakage Current (i) Earth Ground (B) to:

110 to 130 V

U.S.A. o r

Canada

0.15 µF CAP. & 1.5 kΩ

RES. Connected in parallel

i ≤ 0.5 mA rms

Exposed accessible

parts

Chassis or Secondary Conductor

dd'

Primary Circuit Terminals

Fig. 1

AC Voltmeter (High Impedance)

Exposed Accessible Part

Earth Ground Power Cord Plug Prongs

Fig. 2

1-3-1 T1102_SN

STANDARD NOTES FOR SERVICING

Circuit Board Indications

1. The output pin of the 3 pin Regulator ICs is indicated as shown.

2. For other ICs, pin 1 and every fifth pin are indicated as shown.

3. The 1st pin of every male connector is indicated as shown.

Instructions for Connectors

1. When you connect or disconnect the FFC (Flexible Foil Connector) cable, be sure to first disconnect the AC cord.

2. FFC (Flexible Foil Connector) cable should be inserted parallel into the connector, not at an angle.

Pb (Lead) Free Solder

When soldering, be sure to use the Pb free solder.

Information about lead-free soldering

Philips CE is producing lead-free sets from 1.1.2005 onwards.

IDENTIFICATION

Regardless of special logo (not always indicated)

One must treat all sets from onwards, according to the next rule: Serial Number gives a 9-digit. Digit 2&3 shows the WEEK, and digit 4 shows the YEAR.

So from onwards=from 1 Jan 2005 onwards

Important note:

In fact also products of year 2004 must be treated in this way as long as you avoid mixing solder-alloys (leaded/ lead-free). So best to always use SAC305 and the higher temperatures belong to this.

Due to lead-free technology some rules have to be respected by the workshop during a repair:

• Use only lead-free solder alloy Philips SAC305 with

order code 0622 149 00106. If lead-free solderpaste is required, please contact the manufacturer of your solder-equipment. In general use of solderpaste within workshops should be avoided because paste is not easy to store and to handle.

• Use only adequate solder tools applicable for lead-

free solder alloy. The solder tool must be able

• To reach at least a solder-temperature of 400°C,

• To stabilize the adjusted temperature at the solder-

tip

• To exchange solder-tips for different applications.

• Adjust your solder tool so that a temperature around

360°C

- 380°C is reached and stabilized at the solder joint. Heating-time of the solder-joint should not exceed ~ 4 sec. Avoid temperatures above 400°C otherwise wear-out of tips will rise drastically and flux-fluid will be destroyed. To avoid wear-out of tips switch off un-used equipment, or reduce heat.

Top View

Out

Bottom View

Input

Pin 1

FFC Cable

Connector

CBA

* Be careful to avoid a short circuit.

1 Jan 2005

015

1-3-2 T1102_SN

• Mix of lead-free solder alloy / parts with leaded

solder alloy / parts is possible but PHILIPS recommends strongly to avoid mixed solder alloy types (leaded and lead-free). If one cannot avoid or does not know whether product is lead-free, clean carefully the solder-joint from old solder alloy and re-solder with new solder alloy (SAC305).

• Use only original spare-parts listed in the Service-

Manuals. Not listed standard-material (commodities) has to be purchased at external companies.

• Special information for BGA-ICs:

- always use the 12nc-recognizable soldering temperature profile of the specific BGA (for desoldering always use the lead-free temperature profile, in case of doubt)

- lead free BGA-ICs will be delivered in so-called 'dry-packaging' (sealed pack including a silica gel pack) to protect the IC against moisture. After opening, dependent of MSL-level seen on indicatorlabel in the bag, the BGA-IC possibly still has to be baked dry. (MSL=Moisture Sensitivity Level). This will be communicated via AYS-website. Do not re-use BGAs at all.

• For sets produced before 1.1.2005 (except products

of 2004), containing leaded solder-alloy and components, all needed spare-parts will be available till the end of the service-period. For repair of such sets nothing changes.

• On our website

www.atyourservice.ce.Philips.com

you find more

information to:

• BGA-de-/soldering (+ baking instructions)

• Heating-profiles of BGAs and other ICs used in

Philips-sets

You will find this and more technical information within the “magazine”, chapter “workshop news”.

For additional questions please contact your local repair-helpdesk.

How to Remove / Install Flat Pack-IC

1. Removal

With Hot-Air Flat Pack-IC Desoldering Machine:

1. Prepare the hot-air flat pack-IC desoldering machine, then apply hot air to the Flat Pack-IC (about 5 to 6 seconds). (Fig. S-1-1)

2. Remove the flat pack-IC with tweezers while applying the hot air.

3. Bottom of the flat pack-IC is fixed with glue to the CBA; when removing entire flat pack-IC, first apply soldering iron to center of the flat pack-IC and heat up. Then remove (glue will be melted). (Fig. S-1-6)

4. Release the flat pack-IC from the CBA using tweezers. (Fig. S-1-6)

CAUTION:

1. The Flat Pack-IC shape may differ by models. Use an appropriate hot-air flat pack-IC desoldering machine, whose shape matches that of the Flat Pack-IC.

2. Do not supply hot air to the chip parts around the flat pack-IC for over 6 seconds because damage to the chip parts may occur. Put masking tape around the flat pack-IC to protect other parts from damage. (Fig. S-1-2)

3. The flat pack-IC on the CBA is affixed with glue, so be careful not to break or damage the foil of each pin or the solder lands under the IC when removing it.

Fig. S-1-1

Hot-air Flat Pack-IC Desoldering Machine

CBA

Flat Pack-IC

Tweezers

Masking Tape

Fig. S-1-2

1-3-3 T1102_SN

With Soldering Iron:

1. Using desoldering braid, remove the solder from all pins of the flat pack-IC. When you use solder flux which is applied to all pins of the flat pack-IC, you can remove it easily. (Fig. S-1-3)

2. Lift each lead of the flat pack-IC upward one by one, using a sharp pin or wire to which solder will not adhere (iron wire). When heating the pins, use a fine tip soldering iron or a hot air desoldering machine. (Fig. S-1-4)

4. Release the flat pack-IC from the CBA using tweezers. (Fig. S-1-6)

With Iron Wire:

1. Using desoldering braid, remove the solder from all pins of the flat pack-IC. When you use solder flux which is applied to all pins of the flat pack-IC, you can remove it easily. (Fig. S-1-3)

2. Affix the wire to a workbench or solid mounting point, as shown in Fig. S-1-5.

3. While heating the pins using a fine tip soldering iron or hot air blower, pull up the wire as the solder melts so as to lift the IC leads from the CBA contact pads as shown in Fig. S-1-5.

4. Bottom of the flat pack-IC is fixed with glue to the CBA; when removing entire flat pack-IC, first apply soldering iron to center of the flat pack-IC and heat up. Then remove (glue will be melted). (Fig. S-1-6)

5. Release the flat pack-IC from the CBA using tweezers. (Fig. S-1-6)

Note: When using a soldering iron, care must be

taken to ensure that the flat pack-IC is not being held by glue. When the flat pack-IC is removed from the CBA, handle it gently because it may be damaged if force is applied.

Flat Pack-IC

Desoldering Braid

Soldering Iron

Fig. S-1-3

Fine Tip Soldering Iron

Sharp Pin

Fig. S-1-4

To Solid Mounting Point

Soldering Iron

Iron Wire

Hot Air Blower

Fig. S-1-5

Fine Tip Soldering Iron

CBA

Flat Pack-IC

Tweezers

Fig. S-1-6

1-3-4 T1102_SN

2. Installation

1. Using desoldering braid, remove the solder from the foil of each pin of the flat pack-IC on the CBA so you can install a replacement flat pack-IC more easily.

2. The “●” mark on the flat pack-IC indicates pin 1. (See Fig. S-1-7.) Be sure this mark matches the 1 on the PCB when positioning for installation. Then presolder the four corners of the flat pack-IC. (See Fig. S-1-8.)

3. Solder all pins of the flat pack-IC. Be sure that none of the pins have solder bridges.

Instructions for Handling Semiconductors

Electrostatic breakdown of the semi-conductors may occur due to a potential difference caused by electrostatic charge during unpacking or repair work.

1. Ground for Human Body

Be sure to wear a grounding band (1 MΩ) that is properly grounded to remove any static electricity that may be charged on the body.

2. Ground for Workbench

Be sure to place a conductive sheet or copper plate with proper grounding (1 MΩ) on the workbench or other surface, where the semi-conductors are to be placed. Because the static electricity charge on clothing will not escape through the body grounding band, be careful to avoid contacting semi-conductors with your clothing.

Example :

Pin 1 of the Flat Pack-IC is indicated by a " " mark.

Fig. S-1-7

Presolder

CBA

Flat Pack-IC

Fig. S-1-8

CBA

Grounding Band

Conductive Sheet or Copper Plate

1MΩ

CBA

1-4-1 T1102PFS

PREPARATION FOR SERVICING

How to Enter the Service Mode

Caution 1:

1. Optical sensors system are used for Tape Start and End Sensor on this equipment. Read this page carefully and prepare as described on this page before starting to service; otherwise, the unit may operate unexpectedly.

Preparing 1:

1. Cover Q202 (START SENSOR) and Q201 (END SENSOR) with Insulation Tape or enter the service mode to activate Sensor Inhibition automatically.

Note: Avoid playing, rewinding or fast forwarding the

tape to its beginning or end, because both Tape End Sensors are not active.

How to Enter the Service Mode

1. Turn power on.

2. Use service remote control unit and press [DISC MENU] button. (See page 1-7-1.)

3. When entering the service mode, one of the number (1, 2 or 4) will display at corners of the screen.

4. During the service mode, electrical adjustment mode can be selected by remote control key. (Service remote control unit).

Details are as follows.

Caution 2:

1. The deck mechanism assembly is mounted on the Main CBA directly, and SW1211 (REC-SAFETY SW) is mounted on the Main CBA. When deck mechanism assembly is removed from the Main CBA due to servicing, this switch can not be operated automatically.

Preparing 2:

1. To eject the tape, press the [STOP/EJECT] button on the unit (or Remote Control).

2. When you want to record during the Service mode, press the [Rec] button while depressing SW1211 (REC-SAFETY SW) on the Main CBA.

Key Adjustment Mode

PICTURE

Picture adjustment mode: Press the [PICTURE] button to change from BRT (Bright), *CNT (Contrast), *COL (Color), *TNT(Tint), *V-TNT(V-Tint) and *SHP (Sharpness). Press [CH o/p] buttons to display Initial Value. *Marked items are not necessary to adjust normally.

C-Trap adjustment: See adjustment instructions page 1-7-2. Y DL Time TV/Y DL Time EXT/Y SW LPF/Black Stretch Off/ Black Stretch CONT/C. Angle data values setting: See adjustment instructions page 1-7-3.

1 No need to use.

H f

adjustment mode: See adjustment

instructions page 1-7-5.

3 No need to use.

Auto record mode: Perform recording (15 Sec.) --> Stop --> Rewind (Zero return) automatically.

Head switching position adjustment: See adjustment instructions page 1-7-8.

6 No need to use.

Purity check mode: Shows Red, Green, Blue or White cyclically on the screen each time the [7] button is pressed.

H. Position adjustment: See adjustment instructions page 1-7-7.

V. Shift/V.Size adjustment: See adjustment instructions page 1-7-8.

VOL o

CD-VOL/DVD-BRT/DVD-CNT/DVDSHARP data values setting: See adjustment instructions page 1-7-4.

VOL p

Cut-off adjustment: See adjustment instructions page 1-7-5. DATA/SLP REC/MONO data values setting: See adjustment instructions page 1-7-6. White balance adjustment: See adjustment instructions page 1-7-6.

Key Adjustment Mode

MAIN CBA

Q201 (END SENSOR)

SW1211 (REC-SAFETY SW)

Q202 (START SENSOR)

1-5-1 T1102IB

OPERATING CONTROLS AND FUNCTIONS

1-5-2 T1102IB

1-5-3 T1102IB

1-5-4 T1102IB

1-6-1 T1102DC

CABINET DISASSEMBLY INSTRUCTIONS

1. Disassembly Flowchart

This flowchart indicates the disassembly steps for the cabinet parts, and the CBA in order to gain access to item(s) to be serviced. When reassembling, follow the steps in reverse order. Bend, route and dress the cables as they were.

CAUTION!

When removing the CRT, be sure to discharge the Anode Lead of the CRT with the CRT Ground Wire before removing the Anode Cap.

2. Disassembly Method

Note:

(1) Order of steps in procedure. When reassembling,

follow the steps in reverse order. These numbers are also used as the Identification (location) No. of parts in figures.

(2) Parts to be removed or installed.

(3) Fig. No. showing procedure of part location

(4) Identification of parts to be removed, unhooked,

unlocked, released, unplugged, unclamped, or desoldered. P = Spring, L = Locking Tab, S = Screw, CN = Connector * = Unhook, Unlock, Release, Unplug, or Desolder e.g. 2(S-2) = two Screws (S-2), 2(L-2) = two Locking Tabs (L-2)

(5) Refer to the following “Reference Notes in the

Ta b l e” .

Step/

Loc.

No.

Part

Removal

Fig.

No.

Remove/*Unhook/

Unlock/Release/

Unplug/Unclamp/

Desolder

Note

[1]

Rear Cabinet

D1 4(S-1), (S-2), 2(S-3) ---

[2]

Tr ay Chassis Unit

D2 D3 D5

Anode Cap, *CN2501, CRT CBA, *CN1601, *CN1802, *CN2571, *CN2801

[3] CRT

D3 D5

4(S-4) ---

[4]

DVD Mechanism

D2 D4 D5

4(S-5), Wire Holder C, 2(S-6), Loader Cover, *CN201, *CN301

2, 3

[5]

DVD Ma i n CBA Unit

D2 D4D5*CN1, *CN2 ---

[6] Sub CBA

D2 D5

6(S-7), Loader PCB Holder, *CN1301, *CN1602

---

[7]

Function CBA

D2 D5

(S-8), *CN2401 ---

[8]

Deck AssemblyD2D5

3(S-9), Top Shield, 7(S-10), (S-11), (S-12), *CL1201, *CL1401, *CL1402, *CL403

[1] Rear Cabinet

[3] CRT[2] Tray Chassis Unit

[4] DVD

Mechanism

[5] DVD Main

CBA Unit

[6] Sub CBA

[8] Deck Assembly

[9] Main CBA

[7] Function CBA

[9] Main CBA D2 5(S-13) ---

↓

(1)

↓

(2)

↓

(3)

↓

(4)

↓

(5)

Step/

Loc.

No.

Part

Removal

Fig.

No.

Remove/*Unhook/

Unlock/Release/

Unplug/Unclamp/

Desolder

Note

1-6-2 T1102DC

Reference Notes in the Table

CAUTION!

When removing the CRT, be sure to discharge the Anode Lead of the CRT with the CRT Ground Wire before removing the Anode Cap.

1. CAUTION 1: Discharge the Anode Lead of the CRT with the CRT Ground Wire before removing the Anode Cap.

Disconnect the following: Anode Cap, CN2501, CRT CBA, CN1601, CN1802, CN2571 and CN2801. Then remove Tray Chassis Unit.

2. CAUTION 2: Electrostatic breakdown of the laser diode in the optical system block may occur as a potential difference caused by electrostatic charge accumulated on cloth, human body etc., during unpacking or repair work. To avoid damage of pickup follow next procedures.

1) Disconnect Connector (CN301) on the DVD Main CBA Unit.

2) Short the three short lands of FPC cable with solder before removing the FFC cable (CN201) from it. If you disconnect the FFC cable (CN201), the laser diode of pickup will be destroyed. (Fig. D4)

3) Remove four screws (S-5) and Wire Holder C, and remove DVD Mechanism.

3. CAUTION 3: When reassembling, confirm the FFC cable (CN201) is connected completely. Then remove the solder from the three short lands of FPC cable. (Fig. D4)

4. Remove three screws (S-9) and remove Top Shield. Remove screws 7(S-10), (S-11) and (S-

12). Then, desolder connectors (CL1201, CL1401, CL1402, CL403) and lift up the Deck Assembly.

[1] Rear Cabinet

(S-1)

(S-3)

(S-2)

Fig. D1

1-6-3 T1102DC

Wire Holder C

[5] DVD Main CBA Unit

Loader Cover

Loader PCB Holder

[4] DVD Mechanism

[2] Tray Chassis Unit

(S-6)

(S-5)

(S-9)

Top Shield

(S-10)

[8] Deck Assembly

(S-12)

(S-11)

(S-13)

[9] Main CBA

(S-8)

(S-7)

[6] Sub CBA

[7] Function CBA

Fig. D2

1-6-4 T1102DC

[3] CRT

Anode Cap

CRT CBA

(S-4)

Fig. D3

DVD Mechanism

Fig. D4

View for A

Short the three short lands by soldering. (Either of two places.)

Connector

1-6-5 T1102DC

ANODE

CRT

GND

DVD MAIN CBA UNIT

FE HEAD

CYLINDER ASSEMBLY

ACE HEAD ASSEMBLY

CAPSTAN MOTOR

DECK ASSEMBLY

TUNER

MAIN CBA

SUB CBA

CRT CBA

TO SPEAKER

CL2504A

SCREEN

CL2501B

CN2501

FOCUS

CN1802

CL1201

CN1602CN1301

CN1302

CN1803

CL1402

CN1601

CL1401

CL403

CL2501A

CN2571

CN1

CN2

CN2502

CN2503

CN2401

CN2801

AC CORD

FUNCTION CBA

Fig. D5

CN201

CN301

CN2A CN1A

1-7-1 T1102EA

ELECTRICAL ADJUSTMENT INSTRUCTIONS

General Note: “CBA” is abbreviation for “Circuit Board Assembly.”

Note: Electrical adjustments are required after

replacing circuit components and certain mechanical parts. It is important to perform these adjustments only after all repairs and replacements have been completed. Also, do not attempt these adjustments unless the proper equipment is available.

Test Equipment Required

1. NTSC Pattern Generator (Color Bar W/White Window, Red Color, Dot Pattern, Gray Scale, Monoscope, Multi-Burst)

2. AC Milli Voltmeter (RMS)

3. Alignment Tape (VFMS0001H6), Blank Tape

4. DC Voltmeter

5. Oscilloscope: Dual-trace with 10:1 probe, V-Range: 0.001~50 V/Div, F-Range: DC~AC-60 MHz

6. Frequency Counter

7. Plastic Tip Driver

8. Color Analyzer

How to make service remote control unit:

1. Prepare normal remote control unit (Part No. NE206UD). Remove 4 screws from the back lid (Fig. 1-1).

2. Cut off pin 10 of the remote control microprocessor and short circuit pins 10 and 17 of the microprocessor with a jumper wire

How to Set up the Service mode:

Service mode:

1. Use the service remote control unit.

2. Turn the power on. (Use main power on the TV unit.)

3. To enter the TV mode, press [CH. o / p] buttons on the TV unit.

4. Press [DISC MENU] button on the service remote control unit. Version of micro computer will display on the CRT. (Ex: 057-001)

X-Ray Protection Test

X-Ray protection test should be done when replacing any parts of this chassis.

1. Short both ends of R2592 (on Sub CBA).

2. Confirm that the main power turns off.

3. If the main power does not turn off, then replace the following parts (D2591, Q2591, R2592, R2593, R2594 and IC1201).

4. Perform steps 1 to 3 again.

1. DC 114V (+B) Adjustment

Purpose: To obtain correct operation.

Symptom of Misadjustment: The picture is dark and

unit does not operate correctly.

Note: TP2501(+B), J2550(GND) --- Sub CBA,

VR1601 --- Main CBA

1. Connect the unit to AC Power Outlet.

2. Connect DC Volt Meter to TP2501(+B) and J2550(GND).

3. Adjust VR1601 so that the voltage of TP2501(+B) becomes +114±1.0 V DC.

Fig. 1-1

Screws

Remote control unit (bottom)

Test Point Adj. Point Mode Input

TP2501(+B)

J2550(GND)

VR1601 --- ---

Tape M. EQ. Spec.

--- DC Voltmeter +114±1.0 V DC

1-7-2 T1102EA

2. Setting for CONTRAST, COLOR, TINT, V-TINT and SHARP Data Values

General

1. Enter the Service mode. (See page 1-7-1.)

2. Press [PICTURE] button on the service remote

control unit. Display changes “BRT,” “CNT,” “COL,” “TNT,” “V-TNT,” and “SHP” cyclically when [PICTURE] button is pressed.

CONTRAST (CNT)

1. Press [PICTURE] button on the service remote

control unit. Then select “CONTRAST (CNT)” display.

2. Press [CH. o / p] buttons on the service remote

control unit so that the value of “CONTRAST (CNT)” becomes 84.

COLOR (COL)

1. Press [PICTURE] button on the service remote

control unit. Then select “COLOR (COL)” display.

2. Press [CH. o / p] buttons on the service remote

control unit so that the value of “COLOR (COL)” becomes 58.

TINT (TNT)

1. Press [PICTURE] button on the service remote

control unit. Then select “TINT (TNT)” display.

2. Press [CH. o / p] buttons on the service remote

control unit so that the value of “TINT (TNT)” becomes 56.

V-TINT (V-TNT)

1. Press [PICTURE] button on the service remote

control unit. Then select “V-TINT (V-TNT)” display.

2. Press [CH. o / p] buttons on the service remote

control unit so that the value of “V-TINT (V-TNT)” becomes 56.

SHARP (SHP)

1. Press [PICTURE] button on the service remote

control unit. Then select “SHARP (SHP)” display.

2. Press [CH. o / p] buttons on the service remote

control unit so that the value of “SHARP (SHP)” becomes 46.

Note: BRIGHT data value does not need to be

adjusted at this moment.

3. C-Trap Adjustment

Purpose: To get minimum leakage of the color signal

carrier.

Symptom of Misadjustment: If C-Trap Adjustment is incorrect, stripes will appear on the screen.

Note: TP1301(B-OUT) --- Main CBA

1. Connect oscilloscope to TP1301.

2. Input a color bar signal from RF input. Enter the Service mode. (See page 1-7-1.)

3. Press [0] button on the remote control unit and select C-TRAP mode. (Fig. 3)

4. Press [CH. o / p] buttons on the remote control unit so that the carrier leakage B-Out (3.58 MHz) value becomes minimum on the oscilloscope.

Test Point Adj. Point Mode Input

TP1301

(B-OUT)

[CH. o / p]

buttons

--- Color Bar

Tape M. EQ. Spec.

---

Oscilloscope

Pattern Generator

---

Figure

Fig. 2

minimum

1-7-3 T1102EA

4. Setting for Y DL Time TV, Y DL Time EXT, Y SW LPF, Black Stretch Off, Black Stretch CONT and C. Angle Data Values

1. Enter the Service mode. (See page 1-7-1.)

2. Y DL Time TV Adjustment: Press [0] button on

the service remote control unit twice to show “D-T TV” on the display. Y DL Time EXT Adjustment: Press [0] button on the service remote control unit three times to show “D-T EXT” on the display. Y SW LPF Adjustment: Press [0] button on the service remote control unit four times to show “Y SW” on the display. Black Stretch Off Adjustment: Press [0] button on the service remote control unit five times to show “B-S” on the display. Black Stretch CONT Adjustment: Press [0] button on the service remote control unit six times to show “BS2” on the display. C. Angle Adjustment: Press [0] button on the service remote control unit seven times to show “C-ANG” on the display.

3. Y DL Time TV Adjustment: Select “2” by

pressing [CH. o / p] buttons on the service remote control. Y DL Time EXT Adjustment: Select “3” by pressing [CH. o / p] buttons on the service remote control. Y SW LPF Adjustment: Select “0” by pressing [CH. o / p] buttons on the service remote control. Black Stretch Off Adjustment: Select “OFF” by pressing [CH. o / p] buttons on the service remote control. Black Stretch CONT Adjustment: Select “0” by pressing [CH. o / p] buttons on the service remote control. C. Angle Adjustment: Select “103” by pressing [CH. o / p] buttons on the service remote control.

Fig. 3

[0] button

C-TRAP Adjustment (Factory mode)

[CH. ] button

C-TRP 0 C-TRP 1

[CH. ] button

Y DL Time TV Adjustment

[CH. ] button

D-T TV 0 D-T TV 1

[CH. ] button

[0] button

Y DL Time EXT Adjustment

[CH. ] button

D-T EXT 0 D-T EXT 1

[CH. ] button

[0] button

Y SW LPF Adjustment

[0] button

[CH. ] button

Y SW

[CH. ] button

0 Y SW

[0] button

Black Stretch Off Adjustment

[CH. ] button

B-S OFF

[CH. ] button

B-S 0

Black Stretch CONT Adjustment

[CH. ] button

BS2 0

[CH. ] button

[0] button

BS2 1

C. Angle Adjustment

[CH. ] button

C-ANG 103

[CH. ] button

[0] button

C-ANG 95

1-7-4 T1102EA

5. Setting for CD-VOL, DVD-BRT, DVD-CNT and DVD-SHARP Data Values

1. Enter the Service mode. (See page 1-7-1.)

2. CD-VOL Adjustment: Press [VOL o] button on

the service remote control unit once to show “CD VOL” on the display. DVD-BRT Adjustment: Press [VOL o] button on the service remote control unit twice to show “DVD BRT” on the display. DVD-CNT Adjustment: Press [VOL o] button on the service remote control unit three times to show “DVD CNT” on the display. DVD-SHARP Adjustment: Press [VOL o] button on the service remote control unit four times to show “DVD SHP” on the display.

3. CD-VOL Adjustment: Select “7” by pressing [CH.

o / p] buttons on the service remote control. DVD-BRT Adjustment: Select “14” by pressing [CH. o / p] buttons on the service remote control. DVD-CNT Adjustment: Select “0” by pressing [CH. o / p] buttons on the service remote control. DVD-SHARP Adjustment: Select “3” by pressing [CH. o / p] buttons on the service remote control.

Fig. 4

[VOL ] button

CD-VOL Adjustment (Factory mode)

[CH. ] button

[VOL ] button

CD VOL 0 CD VOL 1

[CH. ] button

DVD-BRT Adjustment

[CH. ] button

DVD BRT 0 DVD BRT 1

[CH. ] button

DVD-CNT Adjustment

[CH. ] button

DVD CNT 0 DVD CNT 1

[CH. ] button

[VOL ] button

DVD-SHARP Adjustment

[CH. ] button

DVD SHP 0 DVD SHP 1

[CH. ] button

DVD Key Transmission

DVD KEY

DVD Test

DVD TEST

1-7-5 T1102EA

6. H f0 Adjustment

Purpose: To get correct horizontal position and size of

screen image.

Symptom of Misadjustment: Horizontal position and size of screen image may not be properly displayed.

Note: R2583 --- Sub CBA

1. Connect frequency counter to R2583.

2. Operate the unit for at least 20 minutes.

3. Enter the Service mode. (See page 1-7-1.) Press

[2] button on the remote control unit and select HADJ mode.

4. Press [CH. o / p] buttons on the remote control

unit so that the display will change “0” to “7.”

5. At this moment, choose display “0” to “7” when the

frequency counter display is closest to 15.734 kHz ± 300 Hz.

7. Cut-off Adjustment

Purpose: To adjust the beam current of R, G, B, and

screen voltage.

Symptom of Misadjustment: White color may be reddish, greenish or bluish.

Notes: Screen Control --- FBT (Sub CBA),

FBT = Fly Back Transformer, Use the Remote Control Unit.

1. Degauss the CRT and allow the unit to operate for 20 minutes before starting the alignment.

2. Input the Black raster signal from RF input.

3. Enter the Service mode. (See page 1-7-1.)

4. Press the [VOL p] button. (Press [VOL p] button then display will change “C/D”, “7F” and Initial Setting.)

5. Choose CUT OFF/DRIVE mode then press [1] button. This adjustment mode is CUT OFF (R).

6. Increase the screen control so that the horizontal line just appears on the CRT.

7. Press the [CH. o / p] buttons until the horizontal line becomes white.

8. Choose CUT OFF/DRIVE mode then press [2] button. This adjustment mode is CUT OFF (G). Press [CH. o / p] buttons until the horizontal line becomes white.

9. Choose CUT OFF/DRIVE mode then press [3] button. This adjustment mode is CUT OFF (B). Press [CH. o / p] buttons until the horizontal line becomes white.

Test Point Adj. Point Mode Input

R2583 [CH. o / p] buttons Video ---

Tape M. EQ. Spec.

--- Frequency Counter 15.734 kHz±300 Hz

Test Point Adj. Point Mode Input

---

Screen-Control

[CH. o / p]

buttons

Black

Raster

Tape M. EQ. Spec.

---

Pattern

Generator

See Reference

Notes below.

Figure

Fig. 5-1

Pattern Generator

RF Input

1-7-6 T1102EA

8. Setting for 7F DATA/SLP REC/ MONO Data Values

1. Enter the Service mode. (See page 1-7-1.)

2. 7F Data Adjustment: Press [VOL p] button on

the service remote control unit once to show “7F” on the display. SLP REC Adjustment: Press [VOL p] button on the service remote control unit twice to show “SLP R” on the display. MONO Adjustment: Press [VOL p] button on the service remote control unit three times to show “MONO” on the display.

3. 7F Data Adjustment: Select “FF” by pressing

[CH. o / p] buttons on the service remote control. SLP REC Adjustment: Select “+2” by pressing [CH. o / p] buttons on the service remote control. MONO Adjustment: Select “ON” by pressing [CH. o / p] buttons on the service remote control.

9. White Balance Adjustment

Purpose: To mix red, green and blue beams correctly

for pure white.

Symptom of Misadjustment: White becomes bluish or reddish.

Note: Use service remote control unit

1. Operate the unit more than 20 minutes.

2. Face the unit to the east. Degauss the CRT using a degaussing coil.

3. Input the White Raster (APL 100%).

4. Set the color analyzer to the CHROMA mode and after zero point calibration, bring the optical receptor to the center on the tube surface (CRT).

5. Enter the Service mode. Press [VOL p] button on the service remote control unit and select “C/D” mode. (Display changes “C/D”, “7F” and Initial Setting cyclically when [VOL p] button is pressed.)

6. Press [4] button on the service remote control unit for Red adjustment. Press [5] button on the service remote control unit for Blue adjustment.

7. In each color mode, press [CH. o / p] buttons to adjust the values of color.

8. Adjust Red and Blue color so that the temperature becomes 9200K (x: 286 / y: 294) ±3%.

9. At this time, re-check that horizontal line is white. If not, re-adjust Cut-off Adjustment until the horizontal line becomes pure white.

10. Turn off and on again to return to normal mode. Receive APL 100% white signal and confirm that Chroma temperatures become 9200K (x: 286 / y:

294) ±3%.

Note: Confirm that Cut Off Adj. is correct after this

adjustment, and attempt Cut Off Adj. if needed.

Fig. 5-2

[VOL ] button

7F DATA Adjustment (Factory mode)

[CH. ] button

[VOL ] button

7F= FF 7F= 00

[CH. ] button

SLP REC Adjustment

[CH. ] button

SLP R= +2 SLP R= 0

[CH. ] button

MONO Adjustment

[CH. ] button

MONO= ON MONO= OFF

[CH. ] button

Test Point Adj. Point Mode Input

Screen

[CH. o / p]

buttons

White Raster

(APL 100%)

Tape M. EQ. Spec.

---

Pattern

Generator,

Color analyzer

See below

Figure

Fig. 6

Color Analyzer

1-7-7 T1102EA

10. Sub-Brightness Adjustment

Purpose: To get proper brightness.

Symptom of Misadjustment: If Sub-Brightness is

incorrect, proper brightness cannot be obtained by adjusting the Brightness Control.

Note: SMPTE Setup level --- 7.5 IRE

1. Enter the Service mode. (See page 1-7-1.) Then input SMPTE signal from RF input.

2. Press [PICTURE] button. (Press [PICTURE] button then display will change BRT, CNT, COL, TNT, V-TNT, and SHP). Select BRT and press [CH. o / p] buttons so that the bar is just visible (See above figure).

11. Focus Adjustment

Purpose: Set the optimum Focus.

Symptom of Misadjustment: If Focus Adjustment is

incorrect, blurred images are shown on the display.

Note: Focus VR --- FBT (Sub CBA),

FBT = Fly Back Transformer

1. Operate the unit more than 30 minutes.

2. Face the unit to the East and degauss the CRT using a degaussing coil.

3. Input the monoscope pattern.

4. Adjust the Focus Control on the FBT to obtain a clear picture.

12. H. Position Adjustment

Purpose: To obtain correct horizontal position of

screen image.

Symptom of Misadjustment: H. position may not be properly displayed.

1. Enter the Service mode. (See page 1-7-1.) Press [8] button on the remote control unit and select H-P mode.

2. Input monoscope pattern.

3. Press [CH. o / p] buttons on the remote control unit so that the left and right side of the monoscope pattern are equal to each other.

Test Point Adj. Point Mode Input

---

[CH. o / p]

buttons

---

SMPTE

7.5IRE

Tape M. EQ. Spec.

---

Pattern

Generator

See below

Figure

Fig. 7

White

Black

This bar just visible

Test Point Adj. Point Mode Input

--- Focus Control --- Monoscope

Tape M. EQ. Spec.

--- Pattern Generator See below

Test Point Adj. Point Mode Input

---

[CH. o / p]

buttons

--- Monoscope

Tape M. EQ. Spec.

--- Pattern Generator ---

1-7-8 T1102EA

13. V. Shift Adjustment

Purpose: To obtain correct vertical position of screen

image.

Symptom of Misadjustment: If V. position is incorrect, vertical position of image on the screen may not be properly displayed.

1. Enter the Service mode. (See page 1-7-1.) Press [9] button on the remote control unit and select V-P mode. (Press [9] button then display will change to V-P and V-S).

2. Input monoscope pattern.

3. Press [CH. o / p] buttons on the remote control unit so that the top and bottom of the monoscope pattern are equal to each other.

14. V. Size Adjustment

Purpose: To obtain correct vertical height of screen

image.

Symptom of Misadjustment: If V. Size is incorrect, vertical height of image on the screen may not be properly displayed.

1. Enter the Service mode. (See page 1-7-1.) Press [9] button on the remote control unit and select V-S mode. (Press [9] button then display will change to V-P and V-S).

2. Input monoscope pattern.

3. Press [CH. o / p] buttons on the remote control unit so that the monoscope pattern is 90±5% of display size and the circle is round.

15. Head Switching Position Adjustment

Purpose: Determine the Head Switching Position

during Playback.

Symptom of Misadjustment: May cause Head Switching Noise or Vertical Jitter in the picture.

Note: Unit reads Head Switching Position automatically and displays it on the screen (Upper Left Corner).

1. Playback test tape (VFMS0001H6).

2. Enter the Service mode. (See page 1-7-1.)

Then press the number [5] button on the remote control unit.

3. The Head Switching position will display on the

screen; if adjustment is necessary follow step 4.

6.5H(412.7µs) is preferable.

4. Press [CH. o] or [CH. p] button on the remote

control unit if necessary. The value will be changed in 0.5H steps up or down. Adjustable range is up to 9.5H. If the value is beyond adjustable range, the display will change as: Lower out of range: 0.0H Upper out of range: -.-H

Test Point Adj. Point Mode Input

---

[CH. o / p]

buttons

--- Monoscope

Tape M. EQ. Spec.

--- Pattern Generator ---

Test Point Adj. Point Mode Input

---

[CH. o / p]

buttons

--- Monoscope

Tape M. EQ. Spec.

--- Pattern Generator 90±5%

1-7-9 T1102EA

The following 2 adjustments normally are not attempted in the field. They should be done only when replacing the CRT then adjust as a preparation.

16. Purity Adjustment

Purpose: To obtain pure color.

Symptom of Misadjustment: If Color Purity

Adjustment is incorrect, large areas of color may not be properly displayed.

* This becomes RED COLOR if the [7] button is pressed while in service mode.

1. Set the unit facing east.

2. Operate the unit for over 30 minutes before adjusting.

3. Fully degauss the unit using an external degaussing coil.

4. Set the unit to the AUX mode which is located before CH2 then input a red raster from video in.

5. Loosen the screw on the Deflection Yoke Clamper and pull the Deflection Yoke back away from the screen. (See Fig. 9.)

6. Loosen the Ring Lock and adjust the Purity Magnets so that a red field is obtained at the center of the screen. Tighten Ring Lock. (See Fig. 8, 9.)

7. Slowly push the Deflection Yoke toward the bell of the CRT and set it where a uniform red field is obtained.

8. Tighten the clamp screw on the Deflection Yoke.

17. Convergence Adjustment

Purpose: To obtain proper convergence of red, green

and blue beams.

Symptom of Misadjustment: If Convergence Adjustment is incorrect, the edge of white letters may have color edges.

1. Set the unit to the AUX mode which is located before CH2 then input a dot or crosshatch pattern.

2. Loosen the Ring Lock and align red with blue dots or crosshatch at the center of the screen by rotating (RB) C.P. Magnets. (See Fig. 10.)

3. Align red / blue with green dots at the center of the screen by rotating (RB-G) C.P. Magnet. (See Fig. 11.)

4. Fix the C.P. Magnets by tightening the Ring Lock.

5. Remove the DY Wedges and slightly tilt the Deflection Yoke horizontally and vertically to obtain the best overall convergence.

6. Fix the Deflection Yoke by carefully inserting the DY Wedges between CRT and Deflection Yoke.

Test Point Adj. Point Mode Input

---

Deflection Yoke

Purity Magnet

--- *Red Color

Tape M. EQ. Spec.

--- Pattern Generator See below

Figure

Fig. 8

GREEN RED BLUE

Test Point Adj. Point Mode Input

---

C.P. Magnet (RB)

C.P. Magnet (RB-G)

Deflection Yoke

---

Dot Pattern

Crosshatch

Tape M. EQ. Spec.

--- Pattern Generator See below

Figure

Fig. 9

Fig. 10

Fig. 11

DY WEDGE

DEFLECTION YOKE

C.P. MAGNET

RING LOCK

SCREW

RB-GRB

PURITY

CRT

COIL

COIL CLAMPER

C.P. MAGNET CLAMPER

C.P. MAGNET (RB)

C.B. MAGNET (RB-G)

+ 87 hidden pages

Magnavox 20MC4304/17 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual