Sony CPD-420GS Service manual

CPD-420GS

SERVICE MANUAL

CPD-420GS

China Model

Chassis No. SCC-L20A-A

Picture tube

Video image area

Resolution

Standard image area

Input signal

Video

Sync

SPECIFICATIONS

0.25-0.27 mm aperture grill pitch 19 inches measured diagonally 90-degree deflection Trinitron

(18" maximum viewing image) Approx. 365 X 274 mm (w/h)

3/8

7/8

x 10

inches)

1/2

inches)

(14 Horizontal: Max. 1600 dots

Vertical: Max. 1200 lines Approx. 352 x 264 mm (w/h)

7/8

(13

Analog RGB (75 ohms typical)

0.7 Vp-p, Positive External HD/VD, Composite Polarity Free TTL Video Composite (Sync on Green)

0.3 Vp-p, Negative

D98

Power Consumption

Maximum Nominal

Deflection frequency

AC input voltage / current

Dimensions

Mass

Design and specifications are subject to change without notice.

130 W 100 W

Horizontal: 30 to 96 KHz Vertical: 48 to120 Hz

100 to 120 V, 50/60 Hz, 1.7A 220 to 240V, 50/60Hz, 1.2A

444 x 467 x 455 (w/h/d) (17

Approx. 26 kg (57 lb 5 oz)

CHASSIS

1/2

x 18

x 18 inches)

— 1 —

COLOR MONITOR

CPD-420GS

(

)

POWER SAVING FUNCTION

This monitor has three Power Saving modes. By sensing the absence of a video signal from the computer, it reduces power consumption as follows:

Power Required Recovery

State Consumption Time Power Indicator

Normal Operation

2 Standby (1st mode) 3 Suspend (2nd mode) 4 Active-off (3rd mode)

< 130W Green on

< 15W approx. 5 sec. Green and orange alternate < 15W approx. 5 sec. Green and orange alternate

< 8W approx. 5 sec. Orange 5 Power-off 0 W Off 6 Failure modes See below

SELF DIAGNOSIS FUNCTION

When a failure occurs, the STANDBY/TIMER lamp will flash a set number of times to indicate the possible cause of the problem. If there is more than one error, the lamp will identify the first of the problem areas.

Status Area of Failure LED Indication

1 Failure 1 HV or B+ Orange (0.5 second)/Off (0.5 second) 2 Failure 2 H Stop, V Stop, Thermal Orange (1.5 second)/Off (0.5 second) 3 Failure 3 ABL Orange (0.5 second)/Off (1.5 second) 4 Aging/Self Test Orange (0.5 second)/Off (0.5 second)/

NOTE:

If no video signal is input to the monitor, the "NO INPUT SIGNAL" message appears. After about 30 seconds, the Power Saving function automatically puts the monitor into active-off mode and the indicator lights up orange. Once the monitor detects horizontal and vertical sync signals, the monitor automatically resumes normal operation mode.

Green (0.5 second)/Off(0.5 second)

TIMING SPECIFICATION MODE 1 2 3

Resolution (H x V) 720 X 400 1280 X 960 1600 X 1200 Dot Clock (MHz) 28.321 148.500 202.500

HORIZONTAL

Hor. Freq. (kHz) 31.468 85.938 93.750 H-Total 31.779 11.636 10.667 H-Blanking 6.356 3.017 2.765 H-Front Porch 0.636 0.431 0.316 H-Sync. 3.178 1.077 0.948 H-Back Porch 2.542 1.508 1.501 H-Active 25.423 8.62 7.901

sec

VERTICAL

Ver. Freq. (Hz) 70.084 85.002 75.000 V-Total 449 1011 1250 V-Blanking 4 9 5 1 5 0 V-Front Porch 13 1 1 V-Sync. 2 3 3 V-Back Porch 3 4 4 7 4 6 V-Active 400 960 1200 (lines)

SYNC.

Int (G) No No No Ext (H/V)/Polarity Yes -/+ Yes +/+ Yes +/+ Ext (CS)/Polarity No No No Int/Non Int Non Int Non Int Non Int

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SAFETY CHECK-OUT

(US Model only)

CPD-420GS

After correcting the original service problem, perform

the following safety checks before releasing the set to the

customer:

1. Check the area of your repair for unsoldered or

poorly-soldered connections. Check the entire board

surface for solder splashes and bridges.

2. Check the interboard wiring to ensure that no wires

are “pinched” or contact high-wattage resistors.

3. Check that all control knobs, shields, covers, ground

straps, and mounting hardware have been replaced.

Be absolutely certain that you have replaced all the

insulators.

4. Look for unauthorized replacement parts,

particularly transistors, that were installed during

a previous repair. Point them out to the customer

and recommend their replacement.

5. Look for parts which, though functioning, show

obvious signs of deterioration. Point them out to

the customer and recommend their replacement.

6. Check the line cords for cracks and abrasion.

Recommend the replacement of any such line cord

to the customer.

7. Check the B+ and HV to see if they are specified

values. Make sure your instruments are accurate;

be suspicious of your HV meter if sets always have

low HV.

8. Check the antenna terminals, metal trim,

“metallized" knobs, screws, and all other exposed

metal parts for AC Leakage. Check leakage as

described below.

LEAKAGE TEST

The AC leakage from any exposed metal part to earth ground

and from all exposed metal parts to any exposed metal part having

a return to chassis, must not exceed 0.5 mA (500 microampere).

Leakage current can be measured by any one of three methods.

1. A commercial leakage tester, such as the Simpson 229 or

RCA WT-540A. Follow the manufacturers' instructions to

use these instructions.

2. A battery-operated AC milliammeter. The Data Precision

245 digital multimeter is suitable for this job.

3. Measuring the voltage drop across a resistor by means of

a VOM or battery-operated AC voltmeter. The "limit"

indication is 0.75 V, so analog meters must have an accurate

low voltage scale. The Simpson's 250 and Sanwa

SH-63Trd are examples of passive VOMs that are suitable.

Nearly all battery operated digital multimeters that have a

2V AC range are suitable. (See Fig. A)

WARNING!!WARNING!!

WARNING!!

WARNING!!WARNING!!

NEVER TURN ON THE POWER IN A CONDITION IN WHICH THE DEGAUSS COIL HAS BEEN REMOVED.

SAFETY-RELATED COMPONENT WARNING!! COMPONENTS IDENTIFIED BY SHADING AND MARK ¡ ON THE SCHEMATIC DIAGRAMS, EXPLODED VIEWS AND IN THE PARTS LIST ARE CRITICAL FOR SAFE OPERATION. REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY . CIRCUIT ADJUSTMENTS THAT ARE CRITICAL FOR SAFE OPERATION ARE IDENTIFIED IN THIS MANUAL. FOLLOW THESE PROCEDURES WHENEVER CRITICAL COMPONENTS ARE REPLACED OR IMPROPER OPERATION IS SUSPECTED.

0.15 µF

To Exposed Metal Parts on Set

1.5 k

Earth Ground

AVERTISSEMENT!!

NE JAMAIS METTRE SOUS TENSION QUAND LA BOBINE DE DEMAGNETISATION EST ENLEVEE.

ATTENTION AUX COMPOSANTS RELATIFS A LA

Ω

AC Voltmeter (0.75 V)

LES COMPOSANTS IDENTIFIES PAR UNE TRAME ET PAR UNE MARQUE ¡ SUR LES SCHEMAS DE PRINCIPE, LES VUES EXPLOSEES ET LES LISTES DE PIECES SONT D'UNE IMPORTANCE CRITIQUE POUR LA SECURITE DU FONCTIONNEMENT. NE LES REMPLACER QUE PAR DES COMPOSANTS SONY DONT LE NUMERO DE PIECE EST INDIQUE DANS LE PRESENT MANUEL OU DANS DES SUPPLEMENTS PUBLIES PAR SONY. LES REGLAGES DE CIRCUIT DONT L'IMPORTANCE EST CRITIQUE POUR LA SECURITE DU FONCTIONNEMENT SONT IDENTIFIES DANS LE PRESENT MANUEL. SUIVRE CES PROCEDURES LORS DE CHAQUE REMPLACEMENT DE COMPOSANTS CRITIQUES, OU LORSQU'UN MAUVAIS FONTIONNEMENT SUSPECTE

SECURITE!!

— 3 —

CPD-420GS

Section Title Page

1. GENERAL ................................................................................... 5

2. DISASSEMBLY

2-1. Cabinet Removal ............................................................12

2-2. Service Position .............................................................. 12

2-3. D, A, H and N Board Removal......................................12

2-4. Picture Tube Removal ................................................... 13

3. SAFETY RELATED ADJUSTMENT................................. 14

4. ADJUSTMENTS ........................................................................ 15

5. DIAGRAMS

5-1. Block Diagram ................................................................19

5-2. Circuit Boards Location ................................................. 22

5-3. Schematic Diagrams and Printed Wiring Boards ...... 22

1. D Board - Schematic Diagram .................................23

2. A Board - Schematic Diagram ................................. 27

3. H Board - Schematic Diagram .................................. 31

4. N Board - Schematic Diagram .................................. 32

5-4. Semiconductors ............................................................. 35

6. EXPLODED VIEWS

6-1. Chassis ............................................................................ 37

6-2. Packing Materials .......................................................... 38

7. ELECTRICAL PARTS LIST ................................................ 39

— 4 —

— 5 —

The instructions given here are partial abstracts from the Operating Instruction Manual. The page numbers shown reflect those of the Operating Instruction Manual.

SECTION 1

GENERAL

CPD-420GS

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CPD-420GS

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CPD-420GS

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CPD-420GS

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CPD-420GS

SECTION 2

DISASSEMBLY

2-1. CABINET REMOVAL

Two claws

Cabinet

Two screws

2-2. SERVICE POSITION

PUSH

(BVTP 4 x 16)

2-3. D, A, H and N BOARD REMOVAL

A board

H board

(additional board)

A board

Five screws

(BVTP 3 x 12)

One screw

(BVTT 4 x 8)

rotate 180º

D board

1 When the D-board is placed in service position, the Safety Earth Wire (green and yellow wire) is disconnected. 2 After service is completed and the D-board reinstalled, the Safety Earth Wire must be reattached to the chassis with the proper screw. This must be confirmed before any subsequent procedures are attempted.

H board

N board

Holder

— 12 —

Two Cable stoppers

Two screws

(BVTP 3 x 12)

Cable bracket

D board

+ 28 hidden pages

Sony CPD-420GS Service manual

POWER SAVING FUNCTION

SAFETY CHECK-OUT

TABLE OF CONTENTS

GENERAL

DISASSEMBLY