GDM-500PS, GDM-500PST - Sony Monitor Service Manual (repair manual)

MICROFILM

GDM-500PS

US Model

Canadian Model

Chassis No. SCC-L04E-A

GDM-500PST

AEP Model

Chassis No. SCC-L04B-A

Picture tube

0.25 – 0.27 mm aperture grille pitch

21 inches measured diagonally

90-degree deflection

Viewable image size

Approx. 403.8 

×

 302.2 mm (w/h)

(16 

×

 12 inches)

19.8" viewing image

Resolution

Horizontal: Max. 1600 dots

Vertical: Max. 1200 lines

Standard image area

Approx. 388 

×

 291 mm (w/h)

(15 

3

/

8

 

×

 11 

1

/

2

 inches)

or

Approx. 364 

×

 291 mm (w/h)

(14 

3

/

8

 

×

 11 

1

/

2

 inches)

Deflection frequency

Horizontal: 30 to 107 kHz

Vertical: 48 to 160 Hz

AC input voltage/current

100 to 240 V, 50 – 60 Hz, 2.0 – 1.0 A

Power consumption

Max. 160 W

Dimensions

498 

×

 505 

×

 474 mm (w/h/d)

(19 

5

/

8

 

×

 20 

×

 18 

3

/

4

 inches)

Mass

Approx. 31 kg (68 lb 5 oz)

Supplied accessories

See page 6

Design and specifications are subject to change without notice.

– 2 –

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

microampers).

Leakage current can be measured by any one of three meth-

ods.

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

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

use these instruments.

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” indica-

tion is 0.75 V, so analog meters must have an accurate low-

voltage scale. The Simpson 250 and Sanwa SH-63Trd are ex-

amples of a passive VOMs that are suitable. Nearly all battery

operated digital multimeters that have a 2 V AC range are suit-

able.  (See Fig. A)

¡

¡

After correcting the original service problem, perform the fol-

lowing safety checks before releasing the set to the customer:

1. Check the area of your repair for unsoldered or poorly-sol-

dered 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 transis-

tors, 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 recom-

mend 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.

1.5 k

Ω

0.15 

µ

F

AC
Voltmeter
(0.75 V)

To Exposed Metal
Parts on Set

Earth Ground

Fig. A. Using an AC voltmeter to check AC leakage.

•

The connector for DAS (ECS) adjustment is provided inside the

cover shown below. Be careful with an electrical shock when

connecting the connector with the power supplied. Also, return

the removed cover to the home position.

Rear side

– 3 –

This monitor meets the power-saving guidelines set by VESA and
Energy Star, as well as the more stringent NUTEK .
If the monitor is connected to a computer or video graphics board
that is VESA DPMS (Display Power Management Signaling)
compliant, the monitor will automatically reduce power consump-
tion in three stages as shown below.
You can set the delay time before the monitor enters the power
saving mode using the OSD. Set the time according to “Setting the
power saving delay time” on page 16.

Note
If no video signal is input to the monitor, the “NO INPUT SIG-
NAL” message (page 20) appears.  After the delay time has
passed, the power saving function automatically puts the monitor
into the active-off mode and the u indicator lights up orange. Once
the horizontal and vertical sync signals are detected, the monitor
automatically resumes its normal operation mode.

Failre

+B failure

Horizontal / Vertical
Deflection failure,
Thermal protector

ABL protector

HV failure

Aging / Self Test

Power LED

Yellow

→

Off

(0.5 sec)

(0.5 sec)

Yellow

→

Off

(1.5 sec)

(0.5 sec)

Yellow

→

Off

(0.5 sec)

(1.5 sec)

Yellow

→

Off

→

Yellow

→

Off

(0.25 sec)

(0.5 sec)

(0.25 sec)

(1.25 sec)

Yellow

→

Off

→

Green

→

Off

(0.5 sec)

(0.5 sec)

(0.5 sec)

(0.5 sec)

MODE AT PRODUCTION

MODE 1

MODE 2

RESOLUTION

738 X 414

1600 X 1200

CLOCK

28.322 MHz

229.500 MHz

— HORIZONTAL —

H-FREQ

31.469 kHz

106.250 kHz

usec

usec

H. TOTAL

31.777

9.412

H. BLK

5.720

2.440

H. FP

0.318

0.279

H. SYNC

3.813

0.837

H. BP

1.589

1.325

H. ACTIV

26.057

6.972

— VERTICAL —

V. FREQ(HZ)

70.087 Hz

85.000 Hz

lines

lines

V. TOTAL

449

1250

V. BLK

35

50

V. FP

5

1

V. SYNC

2

3

V. BP

28

46

V. ACTIV

414

1200

 — SYNC  —

INT(G)

NO

NO

EXT(H/V)/POLARITY

YES N/P

YES P/P

EXT(CS)/POLARITY

NO

NO

INT/NON INT

NON INT

NON INT

97.9.10 VER.

Aging Mode (Video Aging) : During Power Save, press “MENU” key for

longer than 2 second.

Self Test (OSD Color Bar)

: During Power Save, press “CONTRAST” +

(

>) key for longer than 2 second.

Reliability Check Mode

: During Power Save, press “CONTRAST” –

(

.) key for longer than 2 second.

1

2

3

4

5

Normal operation

Standby (1st mode)

Suspend (2nd mode)

Active-off (3rd mode)

Power-off

≤

 160 W

≤

 100 W

≤

 15 W

≤

 8 W

0 W

present

absent

present

absent

—

present

present

absent

absent

—

active

blank

blank

blank

—

u

Green

Green and orange
alternate

Green and orange
alternate

Orange

Off

—

Approx. 3 sec.

Approx. 3 sec.

Approx. 10 sec.

—

– 4 –

Note: Hand degauss must be used on stand-by or power-off condition.

This model has an automatic earth magnetism correction function by using an earth
magnetism sensor and a LCC coil. When using a hand degauss while monitor (LCC
coil) is being operated, it sometimes gets magnetized, and the system may not work
properly as a result.

...................................................................

5

2-1.

Cabinet Removal .................................................. 13

2-2.

D Board Removal ................................................ 13

2-3.

G Board Removal ................................................ 14

2-4.

A Board Removal ................................................ 14

2-5.

L Board Removal ................................................. 15

2-6.

I/O Terminal Board Removal ............................... 15

2-7.

Service Position .................................................... 16

2-8.

H and J Boards Removal ..................................... 16

2-9.

Picture Tube Removal ......................................... 17

............ 18

...................................................... 19

5-1.

Block Diagrams .................................................... 21

5-2.

Frame Shcematic Diagram .................................... 27

5-3.

Circuit Boards Location ........................................ 29

5-4.

Schematic Diagrams and Printed Wiring Boards ..... 29

(1) Schematic Diagram of D Board ........................... 33

(2) Schematic Diagrams of G, GA, H,

J and L Boards ..................................................... 37

(3) Schematic Diagram of A Board ........................... 44

5-5.

Semiconductors .................................................... 49

6-1.

Chassis ................................................................. 51

6-2.

Picture Tube ......................................................... 52

6-3.

Packing Materials ................................................ 53

............................ 54