ViewSonic VCDTS23283, A91f+-1 Service Manual

Model No. VCDTS23283

19” Digital Controlled Color Monitor

Service Manual

ViewSonic A91f+-1

ViewSonic



381 Brea Canyon Road, Walnut, California 91789 USA - [phone]

(A91f+-1_SM_830 Rev. 1a – Apr. 2004)

Copyright

Copyright

¤

2004 by ViewSonic Corporation. All rights reserved. No part of this publication may be
reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any language or
computer language, in any form or by any means, electronic, mechanical, magnetic, optical, chemical,
manual or otherwise, without the prior written permission of ViewSonic Corporation.

Disclaimer

ViewSonic makes no representations or warranties, either expressed or implied, with respect to the
contents hereof and specifically disclaims any warranty of merchantability or fitness for any particular
purpose. Further, ViewSonic reserves the right to revise this publication and to make changes from time
to time in the contents hereof without obligation of ViewSonic to notify any person of such revision or
changes.

Revision History

Revision Date Description Of Changes Approval

1a 06/15/04 Initial Release DCN- 4408 Angela Lu

Trademarks

ViewSonic is a registered trademark of ViewSonic Corporation.
All other trademarks used within this document are the property of their respective owners.

Optiquest is a registered trademark of ViewSonic Corporation.

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TABLE OF CONTENTS

2. Specification

3. Front Panel Function Control Description

4. Circuit Description

6. Trouble Shooting Flow Chart

9. Block Diagram,

Schematic Diagrams

7. Recommended Spare Parts List

1. Precautions and Safety Notices

5. Adjusting Procedure

8. Exploded Diagram And Spare Parts List

10

. PCB Layout Diagrams

1

3

14
19

34
43

48
87

73-78

79

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WARNING!

This service information is designed for experience repair technicians only and is not designed for use by the general public.

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 serviced or repaired only by experienced professional technicians.
Any attempt to service or repair the product or products dealt within this service information by anyone else
could result in serious injury or death.

1. CAUTION

No modification of any circuit should be attempted. Service work should only be performed after you are thoroughly
familiar with all of the following safety checks and servicing guide lines.

2. SAFETY CHECK

Care should be taken while servicing this CRT display because of the high voltage used in the deflection circuits.
These voltages are exposed in such areas as the associated flyback and yoke circuits.

3. FIRE & SHOCK HAZARD

3-1 Insert an isolation transformer between the CRT display and AC power line before servicing the chassis.
3-2 In servicing pay attention to original lead dress especially in the high voltage circuit. If a short circuit is found,

replace all parts which have been overheated as a result of the short circuit.
3-3 All the protective devices munt be reinstalled per original design.
3-4 Soldering must be inspected for possible cold solder joints, frayed leads, damaged insulation, solder splashes or

sharp solder points. Be certain to remove all foreign material.

4. LEAKAGE CURRENT COLD CHECK

4-1 Unplug the AC cord and connect a jumper between the two prongs on the plug.
4-2 Turn the CRT display power switch “on”.
4-3 Measure the resistance value with an ohmmeter between the jumpered AC plug and each exposed metallic part

on the CRT display such as the metal frame, screwheads, control shafts, etc. When the exposed metallic part has

a return path to the chassis, the reading should be 1.8 megohm minimum.

5. LEAKAGE CURRENT HOT CHECK

5-1 Plug the AC cord directly into the AC outlet. Do not use an isolation transformer during this check.
5-2 Connect a 1500 ohm, 10 watt resistor, paralleled by a 0.15uF capacitor between each exposed metallic part and

a good earth ground (as shown in Fig.1).
5-3 Use an AC voltmeter with 1000 ohm/volt or more sensitivity and measure the AC voltage across the

combination 1500 ohm resistor and 0.15uF capacitor.

1. Precautions And Safety Noticess

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5-4 Move the resistor connection to each exposed metallic part and measure the voltage.
5-5 Reverse the polarity of the AC plug in the AC outlet and repeat the above measurement.
5-6 Voltage measured must not exceed 7.5 volt RMS, from any exposed metallic part to ground A leakage current

tester may be used in the above hot check, in which case any current measured must not exceed 5.0 milliamp. In
the case of a measurement exceeding the 5.0 milliamp value, a rework is required to eliminate the chance of
shock hazard.

Note： High voltage is present when this CRT display is operating. Always discharge the anode of the picture

tube to the display chassis to prevent shock hazard.

AC VOLTMETER

TO
INSTRUMENT'S
EXPOSED
METAL PARTS

1500 Ω 10W

0.15μF

Fig. 1

(EARTH

GROUND)

6. IMPLOSION PROTECTION

Picture tubes are equipped with an integral implosion protection system, but care should be taken to avoid damage and
scratching during installation. Use only Panasonic replacement picture tubes.

7. X-RADIATION

WARNING：The only potential source of X-Radiation is the picture tube. However when the high voltage circuit is
operating properly there is no possibility of X-Radiation problem. The basic precaution whic h must be exercised is to
keep the high voltage at the following factory-recommended level.

Note：：：： It is important to use an accurate periodically calibrated high voltage meter.

7-1 The

procedure for adjusting high voltage is shown on page 21.

7-2 If can not be adjust 25.0 KV at immediate service is required to prevent the possibility of premature

component failure.

7-3 To prevent X-Radiation possibility it is essential to use the sp ecified p icture tube.

IMPORTANT SAFETY NOTICE

There are special components used in this CRT displays
which are important for safety. These parts are identified

by the international symbol

!

on the schematic
diagram and on the replacement parts list. It is essential
that these critical parts should be replaced with
manufacture’s specified parts to prevent X-RADIATION,
shock, fire, or other hazards. Do not modify the original
design or this will void the original parts and labor
guarantee.

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GENERAL SPECIFICATION

1. SCOPE

1.1 THIS SPECIFICATION DEFINES THE PERFORMANCE OF K986 SBM 19 INCH MULTISYNC

COLOR MONITOR

1.2 PRODUCT CONFIGURATION

TBD

1.3

MAGNETIC REQUIREMENTS

AMERICA (-M) BH = 250 +

10mG, BV = 450 + 10mG

2. INPUT REQUIREMENTS

2.1 AC POWER SUPPLY

2.1.1 POWER SOURCE 90~264VAC 50/60HZ

2.1.2 POWER CONSUMPTION LESS THAN 100W

2.1.3 INRUSH CURRENT LESS THAN 30AP. FOR 1/2 CYCLE AT 110V, LESS THAN 60 AP.

FOR ½ CYCLE AT 240V ON COLD STARTING

2.1.4 INPUT CURRENT 2.0 A MAX IN 110V

2.1.5 LEAKAGE CURRENT 3 mA AT AC 100V/240V

2.1.6 RIPPLE / NOISE SHOULD NOT CAUSE ANY VISIBLE INTERFERENCE

2.1.7 POWER CORD 1.8 METER

2.1.8 SIGNAL CABLE 1.8 METER,

2.2 VIDEO INTERFACE

2.2.1 RGB VIDEO ANALOG 0.7 VP-P AND 1 VP-P POSITIVE INPUT IMPEDANCE 75 OHM

2.2.2 MAX PC VIDEO SIGNAL 950mV WITH NO DAMAGE TO MONITOR

2.2.3 MAX MAC VIDEO SIGNAL 1250mV WITH NO DAMAGE TO MONITOR

2.2.4 SYNC SIGNAL SEPARATE OR COMPOSITE HORIZONTAL AND VERTICAL SYNC TTL LEVEL

2.2.5 INPUT CONNECTOR

15 PINS MINI “D” SUB

PIN NO. SIGNAL PIN NO. SIGNAL

1 RED 9 5V OUT

2 GREEN 10 5V GROUND

3 BLUE 11 GROUND

4 GROUND 12 SDA

5 CHECK SIGNAL 13 H. SYNC

6 R RETURN 14 V. SYNC

7 G RETURN 15 SCL

8 B RETURN

2.2.6 SIGNAL MEMORY MODES 13 PRESET MODES

2.2.7 PLUG & PLAY VESA DDC1 / 2B

2. Specification

2.3 SCANNING FREQUENCY

2.3.1 HORIZONTAL 30 KHZ TO 86KHZ

2.3.2 VERTICAL 50 HZ TO 180 HZ

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3. ADJUSTMENT CONTROL

3.1 USER CONTROL

3.1.1 POWER SWITCH

3.1.2 OSD KEY

1 MENU BUTTON

2 ENTER / SELECT BUTTON

DOWN / DECREASE BUTTON

UP / INCREASE BUTTON

3.2 OSD ADJUSTMENT FUNCTION

CONTRAST / BRIGHTNESS

ZOOM / H-POSITION / H-SIZE / V-POSITION / V-SIZE

PINCUSION / PINBALANCE /TRAPEZOID / PARALLELOGRAM / ROTATION

9300

O

K / 6500OK / 5000OK USER R G B

LANGUAGES ENGLISH / DEUTSCH / FRANCAIS / ESPANOL / ITALIC

H-MOIRE / V-MOIRE

OSD H-POSITION / OSD V-POSITION

INPUT LEVEL

MANUAL DEGAUSS

TOP/BOTTOM HOOK / RESET MEMORY RECALL

OSD

3.3 LED INDICATION

STATUS LED

NORMAL GREEN

POWER SAVING AMBER

POWER ON

OVER RANGE FREQUENCY AMBER

POWER OFF OFF

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4. ELECTRICAL SPECIFICATION

A. ELECTRICAL SPECIFICATION

4.1 STANDARD CONDITION OF MEASUREMENT

4.1.1 BRIGHTNESS – 50% FACTORY SHIPMENT CONDITION

4.1.2 CONTRAST – 100% FACTORY SHIPMENT CONDITION MAX

4.1.3 OTHER SW – FACTORY SHIPMENT CONDITION

4.1.4 BACKGROUND COLOR – BLACK

4.1.5 BRIGHTNESS 30 FL FULL WHITE

4.1.6 TEMPERATURE 0~40 ° C HUMIDITY 5 ~ 90% NON-CONDENSING

4.1.7 POWER INPUT –AC 90~264V 50HZ / 60HZ

4.1.8 TERRESTRIAL MAGNETIC FIELD – NORTHERN HEMISPHERE MAGNETIC FIELD

4.1.9 WARM UP TIME – START TESTING 30 MINUTES OR MORE AFTER POWER ON

4.1.10 TIMING CHART – REFER TO ITEM 7.2.

4.1.11 AMBIENT LIGHTING ENVIRONMENT – 400 TO 600 LUX

4.1.12 CRT FACE TO EAST

4.2 CRT SPECIFICATION

ITEM SPEC
SIZE 19”
DIAGONAL 18”
DEFLECTION

90°

PERSISTENCE MEDIUM SHORT
PHOSPHOR
PITCH

0.25mm

MASK TYPE SHADOW MASK FLAT
FACE PLATE ANTI- REFLECTIVE, ANTI-STATIC

CRT

SDI/M46QCK761X214
LPD/M46QEF903X21

4.3 POWER SAVING

4.3.1 POWER SAVING

HORIZONTAL

SYNC.

VERTICAL SYNC.

POWER

CONSUMPTION

OSD INDICATOR POWER

LED

RECOVERY TIME

YES YES < 100 W NORMAL GREEN N/A

NO YES < 5W POWER SAVING AMBER 10 SEC

YES NO < 5W POWER SAVING AMBER 10 SEC

NO NO < 5 W POWER SAVING AMBER 10 SEC

< 29 KHZ OR

> 87KHZ

< 49 HZ OR

>181 HZ

< 5W FREQUENCY OVER

RANGE

AMBER

10 SEC

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B. SCREEN CHARACTERISTICS

4.4 PICTURE DISPLAY SIZE

HORIZONTAL SIZE 352+

4 mm

VERTICAL SIZE 264+

4 mm

4.5 PICTURE CENTER

PRIMARY MODE (1280X1024/75HZ) LA-BL < 4 mm, LC-DL < 4 mm.

OTHERS MODE LA-BL < 4 mm, LC-DL < 4 mm.

4.6 LINEARITY

12 x 10

INPUT SIGNAL : BLOCK PATTERN

V-LINEARITY :

Xmax
Xmax

Ymax
Ymax

Xmin

Ymin
Ymin

Xmin

X 100%

H-LINEARITY:

X 100%

+

-

+

-

< 4%

< 4%

; WORSE CASE < 5%

4.7 PICTURE DISTORTION

4.7.1 TRAPEZOID / PARALLELOGRAM

4.7.2 PINCUSHION / BARREL / PIN-BALANCE

PICTURE

2mm

268mm

357mm

TRAPEZOID:

HORIZONTAL <= 2mm

VERTICAL <= 2mm

PARALLEL <= 2mm

2mm

2mm

2mm

'

'

C'

PICTURE

PINCUSHION <

BARLEL <

1.5mm

C

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4.7.3 TILT

D

A

B

A - B <= 2mm

.

BEZEL

4.8 MISCONVERGENCE

4.9 FOCUS

4.9.1 UNDER THE CONDITION OF BRIGHTNESS CENTER AND CONTRAST MAXIMUM

“ ME “ PATTERN CAN BE SEEN CLEARLY BY USING THE 1280X1024 69 KHZ/85HZ

IF

NECESSARY, LIMIT SAMPLE AGREED BY BOTH PARTIES WILL BE MADE FOR

FINAL FOCUS JUDGMENT.

4.10 JITTERS

4.10.1 NO VISIBLE

4.11 WHITE BALANCE

4.11.1 COLOR TEMPERATURE USING THE CIE COLOR TEMPERATURE COORDINATE

SYSTEM
COLOR 9300

O

K X = 0.283±0.015; Y = 0.297±0.015

COLOR 6500

O

K X = 0.313±0.020; Y = 0.329±0.020

COLOR 5000

O

K X = 0.346±0.020; Y = 0.359±0.020

PICTURE

357mm

268mm

ZONE A <= 0.25mm

ZONE B <= 0.30mm

B

ZONE C <= 0.35mm

C

A

4.11.2 COLOR PURITY IMPURITY SHOULD NOT APPEAR IN THE PATTERN OF ALL

GREEN ALL RED ALL BLUE OR ALL WHITE

4.11.3 COLOR TRACKING: WHEN THE FULL WHITE PATTERN IS DISPLAYED AT PRESET

(ONLY FOR 9300

O

K) CONDITION. THE DIFFERENCE OF WHITE BALANCE

BETWEEN CONTRAST 30 FL AND LOW CONTRAST 10 FL MUST BE LESS THAN

FOLLOWING VALUE

x AT CONTRAST 30 FL - x AT 25.75 FL < 0.005

y AT CONTRAST 30 FL - y AT 25.75 FL < 0.005

AND: x AT CONTRAST 25.75 FL - x AT 10 FL < 0.009

Y AT CONTRAST 25.75 FL - Y AT 10 FL < 0.009

4.11.4 VIDEO AMPLIFIER LINEARITY INPUT STEP AT 9300

O

K

x 600mV – x 700mV < 0.007

y 600mV – y 700mV < 0.003

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4.12 LIGHT OUTPUT

AT 80 KHZ 1280X1024/75HZ MODE.

4.12.1 LL => AT BLACK PATTERN = 0.4 -1.2FL AT BRIGHTNESS 100%, CONTRAST 0%

FOR 9300

O

K

4.12.2 HL => AT WHITE BLOCK PATTERN = 37-43

FL AT BRIGHTNESS 50%, CONTRAST

100% FOR 9300

O

K

4.12.3 ABL => AT FULL-WHITE PATTERN 28-32

FL, BRIGHTNESS 50%, CONTRAST

100% FOR 9300

O

K

4.13 BRIGHTNESS UNIFORMITY

4.13.1 > 75

% MAXIMUM BETWEEN CENTER TO ANY EIGHT POINTS WITHIN THE

DISPLAY PICTURE FULL WHITE PATTERN

4.14 SIZE REGULATION

4.14.1 STATIC REGULATION

PICTURE GROWTH FROM MINIMUM LIGHT OUTPUT TO MAXIMUM LIGHT OUTPUT

SHALL BE LESS THAN 3mm WHEN PICTURE IS EXCHANGED FROM

4.14.2 DYNAMIC REGULATION

PICTURE GROWTH SHALL BE LESS THAN 1 mm WHEN PICTURE IS EXCHANGED FROM

A

D

F

BC

E

HG

CENTER

PICTURE

BEZEL

BLACK WHITE

A

B

A'

B`

PICTURE

BEZEL

370mm

WHITE

BLACK100mm

100mm

< 1 mm

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5. ENVIRONMENTAL CONDITIONS

5.1 TEMPERATURE AND HUMIDITY AT OPERATION 0 ~ 40 ° C

5 – 95 % RH WITHOUT CONDENSATION

5.2 TEMPERATURE AND HUMIDITY AT STORAGE - 40 ~ 60

°

C

10 – 95 % RH LESS THAN

6

MONTH

5.3 VIBRATION TEST (PACKAGED)

FREQUENCY 5HZ –250 HZ – 5HZ

ACCELERATION 1.0G

SWEEP TIME 1 OCT/MIN.

TEST TIME 60MIN. / AXIS

5.4 DROP TEST (PACKAGED) 61 CM HEIGHT WEAK CORNER, 3 EDGES, 6 FACES, 1 TIME ON

EACH TESTED UNIT, 4 SETS MIN. DROP QTY.

5.5 ALTITUDE

OPERATING 0~3000 METERS.

NON-OPERATING 0~12000 METERS.

6. PHYSICAL SPECIFICATION

6.1 DIMENSION

HEIGHT: 457 mm

WIDTH 445 mm

DEPTH 456 mm

MONITOR WEIGHT 19.2 KG.

6.2 MECHANICAL ADJUSTMENT

TILT - 5/+15 DEGREES
SWIVEL ± 90 DEGREES

6.3 PACKAGING

6.3.1 CARTON DIMENSION

HEIGHT 498 mm

WIDTH 557 mm

DEPTH 577 mm

6.3.2 SHIPPING WEIGHT 22.4 KG

6.3.3 CONTAINER LOADING 320 UNITS WITH PALLET

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7. FACTORY PRESET TIMINGS

7.1 TIMING DIAGRAM

TIMING OF INPUT SIGNALS NOMINAL INPUT LEVEL SPECIFICATION.

INPUT LEVEL

ANALOG VIDEO
RGB: 0.7V ± 3db
SYNC: H.V. SEPARATE SYNC
TTL COMPATIBLE H.V. COMPOSITA SYNC
LOW (0) 0V MIN. 0.65V MAX.
HIGH (1) 2.40V MIN. 3.5V NOM. 5.5V MAX.

TIMING OF INPUT SIGNALS

A: H-TOTAL TIME O: V-TOTAL TIME
B: H-SYNC PULSE WIDTH P: V-SYNC PULSE WIDTH
C: H-BACK PORCH Q: V-BACK PROCH
D: H-DISPLAY TIME R: V-DISPLAY TIME

E: H-FRONT PORCH S: V-FRONT PORCH

VIDEO

C

D

E

B

A

VIDEO

Q

R

S

P

O

VERTICAL

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7.2 PRESET TIMING TABLE

PRESET TIMING TABLE

MODE NO. 1 2 3 4 5 6 7

MODE NAME

VGA

640X

480

VGA
640X

400

VGA
640X

480

VESA

800X

600

VESA

1024X

768

VESA

800X

600

VESA

1024X

768
HORIZONTAL DOTS 640 640 640 800 1024 800 1024
VERTICAL LINES 480 400 480 600 768 600 768
PIXEL CLOCK (MHZ) 25.175 25.175 36.00 49.5 65.000 56.25 78.75
HORIZONTAL FREQ (KHZ) 31.47 31.47 43.269 46.875 48.360 53.674 60.023
SYNC. POLARITY - - - + - +

+
A H.TOTAL (US)
(PIXELS)

31.778
(800)

31.778
(800)

23.111
(832)

21.333
(1056)

20.680
(1344)

18.631
(1048)

16.660

(1312)
B H.SYNC (US)
(PIXELS)

3.813
(96)

3.813 (96) 1.556
(56)

1.616
(80)

2.09

(136)

1.183 (64) 1.129
(96)

C H.SYNC PORCH (US)
(PIXELS)

1.907
(48)

1.907 (48) 2.222
(80)

3.232
(160)

2.460
(160)

2.702 (152) 2.235
(176)

D H.ACTIVE (US)
(PIXELS)

25.422
(640)

25.422
(640)

17.778
(640)

16.162
(800)

15.75

(1024)

14.222
(800)

13.003

(1024)
E H.FRONT PORCH (US)
(PIXELS)

0.636
(16)

0.318 (8) 1.556
(56)

0.323
(16)

0.370
(24)

0 (0) 0.203

(16)
VERTICAL FREQ (HZ) 59.94 70 85.008 75.00 60.000 85 75.029
SYNC. POLARITY - + - + - +

+
O V.TOTAL (MS)
(LINES)

16.684
(525)

14.268
(449)

11.764
(509)

13.333
(625)

16.670
(806)

11.756
(631)

13.328
(800)

P V.SYNC (MS)
(LINES)

0.064
(2)

0.064 (2) 0.069
(3)

0.064
(3)

0.12
(6)

0.056 (3) 0.050
(3)

Q V.BACK PORCH (MS)
(LINES)

1.048
(33)

1.112 (35) 0.578
(25)

0.448
(21)

0.600
(29)

0.503 (27) 0.466
(28)

R V.ACTIVE (MS)
(LINES)

15.254
(480)

12.711
(400)

11.093
(480)

12.800
(600)

15.880
(768)

11.179
(600)

12.795
(768)

S V.FRONT PORCH (MS)
(LINES)

0.318
(10)

0.222 (7) 0.023
(1)

0.021
(1)

0.06
(3)

0

(0)

0.017
(1)

SCANTYPE INTERLACED NO NO NO NO NO NO NO

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PRESET TIMING TABLE (CONTINOUS)

MODE NO. 8 9 10 11 12 13

MODE NAME

VESA

1024X

768

VESA

1280X

1024

VESA

1600X

1200

MAC
640X

480

MAC
832X

624

MAC

1024X

768
HORIZONTAL DOTS 1024 1280 1600 640 832 1024
VERTICAL LINES 768 1024 1200 480 624 768
PIXEL CLOCK (MHZ) 94.5 135.00 162 30.240 57.270 80
HORIZONTAL FREQ (KHZ) 68.677 79.976 75.000 35.000 49.717 60.241
SYNC. POLARITY +

+ + −

-

−
A H.TOTAL (US)
(PIXELS)

14.561
(1376)

12.504
(1688)

13.333
(2160)

28.571
(864)

20.115
(1152)

16.600

(1328)
B H.SYNC (US)
(PIXELS)

1.016 (96) 1.067
(144)

1.185
(192)

2.116
(64)

1.118 (64) 1.200
(96)

C H.SYNC PORCH (US)
(PIXELS)

2.201 (208) 1.837
(248)

1.877
(304)

3.175
(96)

3.911 (224) 2.20
(176)

D H.ACTIVE (US)
(PIXELS)

10.836
(1024)

9.481

(1280)

9.877

(1600)

21.164
(640)

14.528 (832) 12.8
(1024)

E H.FRONT PORCH (US)
(PIXELS)

0 (0) 0.119

(16)

0.395
(64)

2.116
(64)

0 (0) 0.4

(32)
VERTICAL FREQ (HZ) 85 75.025 60.00 66.667 74.55 74.927
SYNC. POLARITY +

+

+

−

-

−

O V.TOTAL (MS)
(LINES)

11.765 (808) 13.329
(1066)

16.667
(1250)

15.000
(525)

13.417 (667) 13.346
(804)

P V.SYNC (MS)
(LINES)

0.044 (3) 0.038
(3)

0.04
(3)

0.086
(3)

0.060 (3) 0.050
(3)

Q V.BACK PORCH (MS)
(LINES)

0.524 (36) 0.475
(38)

0.613
(46)

1.114
(39)

0.784 (39) 0.498
(30)

R V.ACTIVE (MS)
(LINES)

11.183 (768) 12.804
(1024)

16.000
(1200)

13.714
(480)

12.552 (624) 12.749
(768)

S V.FRONT PORCH (MS)
(LINES)

0 (0) 0.013

(1)

0.013
(1)

0.086
(3)

0(0) 0.05

(3)

SCANTYPE INTERLACED NO NO NO NO NO NO

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EDID DATA for SAMSUNG CRT

:

TIME: 09:20:50

DATE: FEB 12, 2004

VIEWSONIC CORPORATION

EDID VERSION # 1, REVISION # 3

DDCTEST FOR: VIEWSONIC A91F+

128 BYTES OF EDID CODE FOR SAMSUNG CRT
_____________________________________________________

0 1 2 3 4 5 6 7 8 9
________________________________________

0 | 00 FF FF FF FF FF FF 00 5A 63

10 | 19 9E 01 01 01 01 01 0E 01 03

20 | 1D 24 1B BE 2A BB B8 A3 52 46
30 | 98 24 0F 48 4C FF FF 80 81 80
40 | C1 40 A9 40 81 40 71 4F 61 59
50 | 45 59 31 59 BC 34 00 98 51 00
60 | 2A 40 10 90 13 00 60 08 11 00
70 | 00 1E 00 00 00 FF 00 50 35 31
80 | 30 34 30 31 30 30 30 30 31 0A
90 | 00 00 00 FD 00 32 B4 1E 56 14
100 |

00 0A 20 20 20 20 2 0 20 00 00

110 | 00 FC 00 41 39 31 66 2B 0A 20
120 |

20 20 20 20 20 20 00 05

___________________ _______________________________

EDID DATA for LG CRT:

TIME: 09:45:14

DATE: FEB 12, 2004

VIEWSONIC CORPORATION

EDID VERSION # 1, REVISION # 3

DDCTEST FOR: VIEWSONIC A91F+

128 BYTES OF EDID CODE FOR LG CRT
_____________________________________________________

0 1 2 3 4 5 6 7 8 9
________________________________________

0 | 00 FF FF FF FF FF FF 00 5A 63
10 | 19 9E 01 01 01 01 01 0E 01 03
20 | 1D 24 1B CE 2A 05 78 A0 56 4A
30 | 99 26 12 48 4C FF FF 80 81 80
40 | C1 40 A9 40 81 40 71 4F 61 59
50 | 45 59 31 59 BC 34 00 98 51 00
60 | 2A 40 10 90 13 00 60 08 11 00
70 | 00 1E 00 00 00 FF 00 50 35 31
80 | 30 34 30 31 30 30 30 30 31 0A
90 | 00 00 00 FD 00 32 B4 1E 56 14
100 | 00 0A 20 20 20 20 20 20 00 00
110 | 00 FC 00 41 39 31 66 2B 0A 20
120 | 20 20 20 20 20 20 00 E0

____

__ __ __

___________________ _______________________________

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Control function﹒

A﹒User control﹒

B﹒OSD function control﹒

1 2

3. Front Panel Function Control Description

A﹒User control﹒

Power switch：Soft power control﹒

Function select button： , ﹒

Adjustment control button

：▽﹑△﹒

Control name﹒

1﹒Power switch：Push-on / push-off switch for soft power control﹒

2﹒LED indication﹒

Status LED

Power on Green

Off mode in 5 sec Orange

Over range freq. Orange

Power off Off

1

2

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3﹒Function select button：

Press the ‘ ’ button to display OSD menu﹒

Press the ‘

▽﹑△

’ button to select menu function or sub-function﹒

Press the ‘ ’ button to enter the select function﹒

4﹒Adjustment control button：

Push the increased ‘△’ or decrease ‘▽’ button for the desired adjustment﹐all adjustment are memorized

automatically immediately﹒

Function select buttons

Adjustment control buttons

Power switcha.

b.

c.

d.

Power-ON indication

1

2

1

2

B. OSD (on screen display) function control method.

. Main menu, Part 1.

1. Contrast / Brightness.

2. H. size / Position.

3. V. size / Position.

4. Pincushion / Balance.

5. Trapezoid / Parallel.

6. Top/Bttom Hook.

7. ZOOM

8. Tilt

. Main menu, Part 2.

9. Degauss

10. H/V Moire.

11. OSD Position.

12. Input Level.

13. View match color.

14. Language.

15. View meter.

16. Memory Recall.

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OSD function control :

Main menu, part1

Note

：

Press button to toggle between

all Controls that appear in pairs on the

Main menu1.

Contrast adjusts the foreground white level of the screen image.

decreases contrast, increases contrast.

Brightness adjusts the background brightness of the screen image.

decreases brightness, increases brightness.

HORIZONTAL SIZE adjusts the width of the screen image.

decreases width of screen image, increases width of screen image.

HORIZONTAL POSITION moves the screen image left or right.

moves the screen image left, moves the screen image right.

VERTICAL SIZE

adjusts the height of the screen image.

decreases the screen height, increases the screen height.

VERTICAL POSITION moves the screen image up and down.

moves the screen image down, moves the screen image up.

PINCUSHION straightens the vertical sides of the screen image by curving them inward or out ward.

curves the vertical edges inward, curves the vertical edges outward.

PIN BALANCE straightens the vertical sides of the screen image by curving them to the right or to the left.

scurves the vertical edges to the left, curves the vertical edges to the right.

TRAPEZOID make vertical sides of the screen image parallel.

narrows the top and widens the bottom, widens the top and narrows the bottom.

PARALLEL (parallelogram) slants vertical edges of the screen to the left or right.

slants vertical edges to left, slants vertical edges to right.

2

MA I N ME N U 1

CONTRAST / BR I GHTNESS

H.SI ZE/POSI TION
V.SIZE/POSITION
P I NCUSH I ON / BA L ANCE

TRAPEZO I D / PARALLEL
TOP / BOT T OM HOOK
ZOOM
TILT

EX I T : 1 SELECT :2

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TOP HOOK

Straightens the top corners of the screen image. [▽] or [△] to adjust.

BOTTOM HOOK

Straightens the bottom corners of the screen image. [▽] or [△] to adjust.

ZOOM CONTROL

to diminish H-Size

＆ V-Size, △ to enlarge H-Size ＆ V-Size.

TILT

rotates the entire screen image.

rotates the screen counter-clockwise, rotates the screen clockwise.

Main menu, part12

MA I N MEN U 2

DEGAUSS

H/V MOIRE
OSD POS I T I ON

I NPUT LEVEL

VIEWMATCH COLOR

LANGUAGE
VIEWMETER
MEMORY RECAL L

EX I T : 1 SELECT : 2

OSD

OSD

?

DEGAUSS manual degauss function.

Press button to active manual degauss function.

H MOIRE reduces vertical interference that causes unwanted color textures or patterns.

Press

▽

or △ to adjust.

V MOIRE reduces horizontal interference patterns that causes unwanted color textures or patterns.

Press

▽

or △ to adjust.

OSD H-Position control

Press the

▽, △ button.

▽ move OSD to left side, △ move OSD to right side﹒

OSD V-Position control

Press the ▽, △ button.

△

move OSD to up, ▽ move OSD to down.

INPUT LEVEL displays the voltage level of the video signal.

2

OSD

OSD

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VIEWMATCH COLOR provides three color adjustment modes : 9300oK, 6500oK, 5000 oK and User.

Press button to select color adjustment mode.

LANGUAGE to select a language use

▽

and △ to highlight English, French, German, Italian, or Spanish,

Then press button .

VIEWMETER displays the signal input coming from your computer (horizontal scan and refresh rate).

Press button to select this feature.

MEMORY RECALL

returns adjustment back to factory setting only if the monitor is operating in a factory

preset mode.

If you make an adjustment you don’t like, press button to recall factory setting.

DIAGNOSTIC MESSAGE:

1.If monitor into DPMS mode will show:
Display Time : 5 seconds

Back ground : Blue

Characters

: White

Horizontal

2.If input V-sync or H-sync out of pull-in range will show:
H:30KHz ~ 86KHz V:50Hz ~ 180Hz

Display Time

Pull-in range

H . V FREQUENCY

Back ground

: Blue

OVER RANGE

Characters : White

Off Pulses

No Pulses

Off

No Pulses

No Pulses

Mode

Signals

Vertical

Off

No Pulses

Pulses

: 25 seconds

:

Off mode in 5 sec

OFF MODE IN 5 SEC

OFF MODE IN 5 SEC

OFF MODE IN 5 SEC

2

2

?

2

2

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1﹒ POWER SUPPLY﹒

1.1 Power supply﹒
A﹒ Primary Side﹒

The raw DC voltage is built on C101 from AC line voltage through EMI filter﹐and bridge rectifier CR101﹐then
composes with main transformer（T101）﹐switching MOSFET（Q101）and PWM IC（IC101）to form a DC-DC

voltage converter by fly back switching topology, which means that the power energy is pumped up at primary
winding of transformer during duty “ON” cycle﹐then transfer the stored energy to primary side﹐and voltage

regulated by PWM IC（3842）using way of pulse width modulation﹒

The IC101 starts up through some components composed of R103﹐R104﹐R105﹐Q102﹐ZD101 D110.R118.
R107 to build up VCC voltage at pin7﹐and supplied by transformer once secondary voltage is established﹒

IC101 have to work synchronously with horizontal sync by feeding fly back pulse through C110﹒
R124 .R125, C112 and D114 composed a soft-start circuit to prevent over-stress occurred during power start﹒

The TP202：40V voltage can be adjusted through VR101﹒

B﹒ Secondary﹒
Each raw of DC voltage output from T101﹒
a﹒ TP201 voltage output from T101 pin9 and is rectified by D202﹐C201﹒
b﹒ TP202 voltage output from T101 pin14 and is rectified by D203﹐D214. C202﹒
c﹒ TP203 voltage output from T101 pin15 and is received by D205﹐C205﹒
d﹒ TP204 voltage output from T101 pin16 and is rectified by D206﹐C206﹒

e﹒ TP205 voltage output from T101 Pin15 and is rectified by Q206﹐ZD201 and D208.C210. ﹒

f﹒ TP206 voltage output from TP204 and is rectified by Q208.Q209.﹐R214. R215.and R213﹒

g﹒ TP207 voltage output from T204﹒and is rectified by Q210 ZD202 D209 R217.C211and C212.

1.2 Power saving﹒
The EPA power management state as follows：

State SUS Pd Power consummation LED

Normal H H 110W Green

Active off L L ≤ 5W Amber

SUS = IC301（MCU）pin17 output﹒
PD = IC301（MCU）pin18 output﹒

There is no output from Q206 and Q203 while is in Active off mode and SUS（IC301 pin17）and PD
（IC301 pin18）are at low level voltage﹒That is, there is no output for 12V and 6.3V﹒

1.3 Degauss﹒

When the powers is on and when press manual degauss﹐IC301 pin20 output high level voltage to turn on
Q201﹐RL101 and activate Degauss﹒

4. Circuit Description

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2﹒ VERTICAL﹒

2.1 Auto SYNC Deflection control and B+ control circuit Horizontal and vertical sync through IC401 TDA9113
transmit﹒

Deflection controller IC401 TDA9113：
a﹒ The control input（V-position﹐H-position﹐V-s iz e﹐H-size﹐Pincushion﹐Pin-Balance﹐Trapezoid﹐

Parallelogram. TOP Corner. Bottom Corner. Zoom, moiré）are use I

2

C control﹒

b﹒ SYNC input：

H-sync（pin1）（From IC301 pin33）﹒
V-sync（pin2）（From IC301 pin32）﹒
c﹒ Output：

∗ B

+

Driver（pin28）﹒
∗ H-Driver（pin26）﹒
∗ EW-Driver（pin24）﹒

∗ Focus（pin32）﹒

∗ V out（pin23）﹒

2.1.1 Horizontal﹒
a﹒ Then take a HFLB pulse from horizontal output Q407 collector C418 and C419 mid voltage to
IC401 for AFC to make pin12 control H-Drive﹒
b﹒ Pin5 and pin6（C410﹐R410）control horizontal hold in range﹒

2.1.2 Vertical﹒

a. V-sync outputs from MCU IC301 pin32 to IC401 pin2﹐then than smite from pin23﹐pin 13 to

IC501 TDA8172 pin1and pin7﹒
b. IC401 pin3﹐pin7 outputs to vertical hold in range is controlled by pin22（C440）﹒

2.1.3 B

+

control﹒

Take a pulse from T403 pin2 and accumulates to become a DC voltage via Q409﹐Q401.Q402.

R418 ,and .R424 to IC 401 pin 28. (Step up circuit control).

2.2 Vertical deflection﹒
a﹒ IC401 pin23 and pin13 output to IC501（TDA8172）pin7 and pin1﹐then IC501 pin5 and pin7 make
vertical deflection output﹒
b﹒ Vertical blank：IC501 pin3 take a blanking pulse﹐After passing Q501 buffer can supply video blanking
signal﹒

2.3 Boost converter﹒

The Booster converter mainly composes of n-channel MOSFET Q409 Transformer T403 capacitor C442 and

rectifier diode D408. IC401 pin28 B

+

driver output via Q401, Q402, to driver Booster converter

and provide a DC-voltage to provide B

+

H-output circuit use﹐As H-freq. change﹐IC401 pin28 B+-driver

will change its output﹐Booster converter will also change the B

+

it provides﹐H-freq. will varies from

30K ~ 86KHz﹐B+ will varies from 40V ~ 180V﹒

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2.4 X-RAY radiation protection﹒

FBT pin6 output one pulse to pass through D4407.ZD4403 .D4408 and C4420 integration DC voltage﹐and
through D4420.Q4404.IC402.pin 2﹐when anode voltage abnormal increase﹐FBT pin6 and IC402 pin2 voltage
to be increased﹐too﹒
As IC402 pin2 ≅0.6V﹐IC402 X-RAY protection circuit immediately active﹐High voltage to shut-down﹒

The X-RAY radiation protection circuit used in this monitor is a latching type the monitor will shown down
and continue until turn-off the monitor with power switch﹒

3﹒ Horizontal﹒

3.1 Horizontal driver circuit﹒

The output of IC401 pin26 H-Driver connect to Q403.Q404 H-Buffer transistor makes The Q403.Q404 push
pull output to Q406 H-driver, push H-output Q407 to reach secondary via induction of T4401﹒For T4401 is a

Transformer of reduced voltage and converted pole﹐Q407 will be turn off when Q406 is on﹐on the contrary﹐
went Q406 is turn off and Q407 will be on﹒

3.2 Horizontal output circuit﹒

Horizontal output circuit is composed by Q407（Horizontal Transistor）﹐CRT YOKE.D406.C418 and C419.

H-output circuit﹐H-Driver circuit output via T4401to switch Q407 ON/OFF to output saw tooth wave and make
DY able to control the circuit scanning of elections in the CRT﹒
L403﹐L404﹐C427﹐C432﹐C428 and C429 modify Horizontal linearity switching individually Dai RL401﹐
Q415﹐Q411﹒

3.3 EW-Pincushion and width control circuit

The parabolic waveform and DC voltage and generated from IC401 pin24 to Q405, R421, R422 to IC401
pin15﹒

The parabolic decreased or increased for compensating the pincushion effect the DC voltage control the
H-width﹒

3.4 High-voltage circuit

High-voltage circuit is composed by Q4401.T401 (FBT) and.C4406 .High-voltage output stage .

The IC 402 is PWM duty-cycle control.

1. Q4405 High voltage buffer stage.

2. Q4401 High voltage output stage.

3. Q4402 PWM control Driver stage.

4. Q4407.Q4408 .and Q4410 Brightness control circuit .

5. Q4406 D4426.R4429.R4430.VR4402 andC4427. ABL control circuit.

6. VR4401 High voltage control.

7. VR4402 ABL Lever control.

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4﹒ Video﹒

4.1 Video amplifier（IC601）﹒
The video amplifier module is composed of three amplifiers for Red﹐Green﹐Blue channel﹒

The video input signal is fed to the video preamplifier IC601（KA2500）pin8 Red﹐pin5 Green﹐pin10 Blue﹐
through AC coupling capacitor﹐C601﹐C601﹐C603﹒

The clamping pulse comes from IC301 pin33﹒

IC603 output amplifier for B﹑R﹑G channel respectively﹒

4.2 On Screen Display（OSD）（IC602）﹒
IC602（NT6827-0047）is a on screen display generator, pin5 for H-sync input﹐pin10 for V- sync input﹒
The IC602 is controlled by IC301 via SCL﹐SDA bus IC602（pin7﹐pin8）﹒

The on screen display signal is output from pin15（r）﹐pin14（g）﹐pin13（b）and OSD BLK to IC601 pin2﹐

pin1﹐pin3﹐pin4﹒

4.3 Auto Beam Limit CKT（ABL CKT）﹒

When beam current pass through VR4402 over 500uA﹐the voltage build at base of Q4406 will be low enough
to turn on Q4406﹐then the voltage of pin12 of IC601 will be pulled down accordingly to reduce the video
preamplifier gain output﹒

4.4 Brightness Control﹒

Brightness is controlled by varying the DC voltage of G1 with the IC301 PIN1（PWM）﹒

`

4.5 Blanking CKT﹒

IC501（TDA8172）pin3 vertical blanking pulse are fed to the base of Q501﹐The blanking pulse O/P is coupled
to G1 by C507﹒

Horizontal blanking pulse are fed to IC601 pin19 and let video O/P amp cut off during the period of horizontal
retrace﹐while mode change﹐IC301 pin19 will pull high to turn off﹒The G1 voltage will down to –180V then

CRT will cut off the video output﹒

5﹒ Tilt﹒

IC301 pin2 PWM to tilt circuit﹐Q211 and Q213 control flow of current of Rotation coil﹐when the base of C215
increase from 0 to 12V﹐As Q211 will turn on gradually﹐the current starts from 14V to 6.3V via Rotate coil﹒
When C215decrease from 12V to 0V﹐the current will change from 6.3V to GND﹒

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