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Service Manual
19-inch Color Monitor
B1996NST /NSL
Service Manual Versions and Revision
No. Ve rsion Re le ase Dat e Re vision
1. 1.0 Oct. 7, 1999 Original release
Copyright Trademarks
Copyright 1999 LiteOn Technology Corp. LiteOn is a registered trademark of LiteOn
Technology Corp.
All Rights Reserved
All other trademarks are the property of their
This manual may not, in whole or in part, be
respective owners.
copied, photocopied, reproduced, translated, or
converted to any electronic or machine readable
form without prior written permission of LiteOn
Technology Corp.
B1996NST/NST Service Manual.
Printed in Taiwan.
B1996NST/NSL
Table of Contents
1. Precautions.........................................................................................................2
2. Product Specifications .......................................................................................5
3 Control Location and Functions ...................................................................... 10
4. Operation Theory.............................................................................................. 11
5. Alignments and Adjustments ........................................................................... 16
6. Troubleshooting ............................................................................................... 21
7. Recommended Spare Parts List ....................................................................... 27
8. Block Diagram ................................................................................................ 29
9. Exploded Diagrams.................................................................................. Inserted
10. PCB Diagrams ......................................................................................... Inserted
11. Schematic Diagrams ................................................................................ Inserted
Page 1
B1996NST/NSL
1 Precautions
Follow these safety and servicing precautions to prevent damage and to protect against potential hazards
such as electrical shock and X-rays.
1-1 Safety Precautions nonmetallic control knobs, insulating materials,
cabinet backs, adjustment and compartment
covers or shields, isolation resistor-capacitor
1-1-1 Warnings networks, mechanical insulators, etc.
1. For safety purpose, do not attempt to modify 3. AC Leakage Current Check
the circuit board, and always disconnect the AC Always perform the AC Leakage Current
power before performing servicing on the Check on the exposed metal parts, including
monitor. metal cabinets, screwheads and control shafts,
2. Operation of the monitor outside its cabinet or as follows:
with the cover removed involves the risk of a) Plug the AC line cord directly into a rated
shock hazard. Repair work on the monitor AC outlet. Do not use an isolation
should only be attempted by service personnel transformer during the check.
who are thoroughly familiar with all necessary
b) Use an AC voltmeter with at least 5000
safety precautions and procedures for working
ohms per volt sensitivity as follows:
on high voltage equipment.
Connect a 1500 ohms, 10 watt resistor
3. Do not lift the CRT by the neck. After
paralleled by a 0.15uF AC capacitor in series
completely discharging the high voltage anode,
with all exposed metal cabinet parts and a
handle the CRT only when wearing shatterproof
known earth ground, such as electrical
goggles. Try to keep the CRT away from the
conduct or electrical ground connected to
body during handling.
earth ground, as shown in the Figure 1-1.
4. High voltage should always be kept at the rated Measure the AC voltage across the
value, no higher. Only when high voltage is combination of resistor and capacitor.
excessive are X-rays capable of penetrating the
shell of the CRT. Operation at high voltages Figure 1-1. Set Up For AC Leakage Current Check
may also cause failure of the CRT or high
voltage circuitry.
5. The CRT is especially constructed to limit X-
ray emission to 0.5mR/HR at 300 microamperes
anode current. To ensure continued X-ray
protection, replace the CRT with only the same To kn ow n To ex pos ed m e ta l
ca bin et p art
or equivalent type as the original, and adjust the ea rth g ro un d
0.15 ufd
anode's voltage to the designated maximum
rating, never to exceed.
1500 ohm 10 w att
1-1-2 Safety Checks
Before returning the monitor to the user, perform
c) Reverse the AC plug at the AC outlet and
the following safety checks:
repeat the steps for AC voltage
1. Inspect to make certain that each lead dress is measurements for each exposed metal part.
not pinched or that hardware is not lodged
d) Voltage reading must not exceed 0.3 volts
between the chassis and other metal parts in
RMS, equivalent to 0.2 milliampere AC. Any
the monitor.
value exceeding this limit ill constitute a
2. Inspect all protective devices such as potential shock hazard and must be
corrected immediately.
Page 2
B1996NST/NSL
1-1-3 Product Safety Notices
Many electrical and mechanical parts in this chassis have special safety-related characteristics which are
often not evident from visual inspection, the protection afforded by them may not be obtained by replacing
them with components rated for higher voltage, wattage, etc. Before replacing any of these components,
consult the Recommended Spare Parts List given at the end of this manual. Any of the replacements that do
not provide the same safety characteristics may result in shock, fire, X-ray emission or other hazards.
1-2 Servicing Precautions
Warning: An electrolytic capacitor installed with the wrong polarity might explode.
Caution: Before performing servicing covered by this service manual, read and follow the Safety Precautions
section of this manual.
Note: If unforeseen conflict between the following servicing precautions and any of the safety
precautions, always follow the safety precautions
1. Follow closely the servicing precautions printed on the monitor cabinet and chassis.
2. Always unplug the AC power cord from the AC power source before removing or installing any component
or assembly, disconnecting PCB plugs or connectors and connecting a test component in parallel with a
capacitor.
3. When replacing parts or circuit boards, clamp the lead wires around the component before soldering.
4. When replacing a high wattage resistor (>0.5W metal oxide film resistor) in the circuit board, keep the
resistor about 1 cm (1/2 inch) away from the circuit board.
5. Keep wires away from the high voltage or high temperature components.
6. Keep wires in their original positions so as to minimize interference.
7. Always connect a test instrument's ground lead to the instrument chassis ground before connecting the
positive lead; always remove the instrument's ground lead last.
After putting the rear cover back and make sure the monitor is working properly, the Hi-Pot &
Ground Continuity tests MUST BE performed before the monitor is returned to user.
1-3 Hi-Pot Test
1. Test Equipment
Puncture test model PM5530 ADT or KIKUSU TOS-8750 voltage tester or equivalent approved equipment.
Note : The test equipment must be calibrated in regular period.
2. Test Setup
a) Apply voltage : DC 2100 VDC
b) Test duration : 3 seconds
c) Cutoff current should be set to 3 mA
3. Test Procedure
a) Unplug power cord from AC source.
b) Put the power switch of the monitor in the "ON" position.
c) Leave signal cable un-connected.
Page 3
B1996NST/NSL
d) Plug monitor power cord to the Hi Pot tester terminals.
e) Turn on tester and watch the indicator or beeper.
f) If the indicator lamp lighten, or beeper beeps, the test fails.
1-4 Ground Continuity Test
1. Test Equipment
AC low ohm tester TOS-6100 or equivalent approved equipment.
Note : The test equipment must be calibrated in regular period.
2. Test Setup
a) Test duration : 3 seconds
b) Set current limit at 25 A
c) The grounding resistance must be less than 0.1 ohm.
3. Test Procedure
a) Plug the monitor power cord to the tester terminals.
b) Make sure all connections are well-contacted.
c) Turn on monitor power and tester power.
d) Press "Test" button.
e) If green light shows up, means test OK.
If red light shows up, means test fails.
f) If the Tester has a digital display, the resistance value must not exceed 0.1 ohm.
Note : Be sure not to touch the metal portion of the signal cable head during testing.
Page 4
B1996NST/NSL
2 Product Specifications
2-1 Specifications
19- i nc h, ( 18- i nc h vi s ua l i mage a r ea ) s l ote d ma s k, 90
de gr e e s de fl e cti on, dot type bl ac k ma tr i x, med i um s hor t
Pi c tur e Tub e
pe r s i s tenc e pho s phor, d ar k ti nt, non- gl a r e / a nti - s tati c
s c r ee n,
0.26 mm dot pi tch
Sca nni ng Fr eq ue ncy VGA, Super VGA, 1024x768@75/ 85 Hz, 1280x1024@85 Hz
Ma xi mum Re s ol uti o n 1600 dots ( H) x 1200 l i ne s ( V) @75Hz r efr es h r ate
Di s p l a y Ar e a 350 mm ( H) x 262 mm ( V) typi c al
Di s p l a y Char a c ter s 80 cha r. x 60 r ow s on a 10 x 10 ma tr i x
Di s p l a y Col or s Anal og
Unl i mi te d Col or s
Input
Sepa r a te Sync : hor i zonta l / v er ti c a l , TTL, p os i ti ve or
Sync hr oni zati n Si gna l s
nega ti ve
Sync hr oni zati on Hor i zo nta l : 30 to 95 kHz
Fr e que nc i e s Ver ti c a l : 5 5 to 160 Hz
Si gna l Connec tor s 15- pi n, D- s he l l c onne c tor
Vi de o Si gna l s Ana l og : 0.7 Vp- p , RGB pos i ti ve
Pow e r Input 130 Wa tts ( ma xi mum) AC r a ted vol ta ge , 100VAC to 2 40VAC
Mi s co nve r genc e Ce nter Ar e a : < 0 .3 mm; Cor ne r Ar ea : < 0 .4 mm
Pow e r On/ Off, Contr as t, Br i ghtnes s , Hor i zonta l Si ze ,
Hor i zo nta l Pos i ti on, Ve r ti c al Si ze , Ve r ti ca l Po s i ti on,
Us er Contr ol s
Pi ncus hi on, Tr a pezoi d, Pi n Ba l a nc e , Par a l l el ogr a m,
Rota ti on, Col or te mp er a tur e , Langua ge , Di s pl a y Fr e que nc y,
Dega us s , Rec a l l , H. Moi r e, V. Moi r e
Ser vi ce Contr ol s PWB- 146 5/ 1466 : pow e r vol tage a dj us t ( VR801 ) ,
hi gh vol ta ge ad j us t ( VR101) , foc us 1,
foc us 2
Pr e s e t Mo des 14 ( s ee Ta bl e 2- 2. Ti mi ng Char t)
Envi r onmenta l Ope r a ti o n tempe r atur e : 5 o C to 40 o C ambi ent
Cons i de r a ti ons Ope r a ti o n Humi di ty : 20% to 80% ambi ent
Stor a ge te mpe r a tur e : - 40 o C to 65 o C ambi ent
Stor a ge Humi di ty : 5% to 95% ( non- c onde ns i ng)
Al ti tude : up to 3000m a bove s ea l eve l
Note: Above specifications are subject to change without prior notice.
Page 5
B1996NST/NSL
2-2 Signal Cable Pin Connections
Table 2-1. Signal Cable Pin Assignments
Pin Signal Pin Signal
1 Red vi de o 9 +5V
2 Gr een vi deo 10 Di gi tal Gr ound
3 Bl ue vi de o 11 Gr ound
4 Gr ound 12 SDA
5* NC 13 H- Sync
6 Red gr ound 14 V- Sync / VCL
7 Gr een gr ound 15 SCL
8 Bl ue gr ound
Note: * This pin is used for selftest detection. Connect this pin to ground at the PC end.
Page 6
B1996NST/NSL
2-3 Timing Chart
This section describes the timings that the computer industry recognizes as standard for computer-generated
video signals.
Table 2-2. Timing Chart
Mode 1 2 3 4 5 6 7 8 9 10 11 12 13 14
H. Dot s 640 640 720 640 800 832 800 1024 1152 1024 1600 1280 1280 1600
V. Dot s 480 480 400 480 600 624 600 768 870 768 1200 1024 1024 1200
H- f re q ( kHz ) 31.47 37.5 37.927 43.27 46.885 49.725 53.67 60.03 68.681 68.67 75 80 91.146 93.75
Sync
- - - - + - + + - + - + + +
Polarit y
A pe riod us 31.78 26.7 26.366 23.11 21.333 20.11 18.631 16.66 14.56 14.561 13.333 12.504 10.971 10.667
B Blking us 6.356 6.349 6.085 5.33 5.172 5.586 4.409 3.657 3.04 3.725 3.457 3.022 2.844 2.765
C Sync us 3.81 2.032 2.028 1.556 1.616 1.117 1.138 1.219 1.28 1.016 1.185 1.067 1.016 0.948
D B.P. us 1.907 3.81 3.042 2.22 3.232 3.91 2.702 2.235 1.44 2.201 1.877 1.837 1.422 1.501
E Ac t ive us 25.42 20.317 20.282 17.78 16.162 14.524 14.222 13 11.52 10.836 9.877 9.481 8.127 7.901
F F.P. us 0.636 0.508 1.014 1.556 0.323 0.559 0.569 0.203 0.32 0.508 0.395 0.119 0.406 0.316
V- f re q ( Hz ) 59.94 75 85 85 75 74.55 85 75.03 75.062 84.99 60 75 85 75
Sync
- - + - + - + + - + - + + +
Polarit y
O Pe riod ms 16.68 13.3 11.759 11.76 13.33 13.414 11.756 13.33 13.322 11.765 16.667 13.329 11.761 13.333
P Blking ms 1.43 0.533 1.213 0.67 0.533 0.864 0.578 0.533 0.656 0.582 0.667 0.525 0.527 0.533
Q Sync ms 0.064 0.08 0.079 0.069 0.064 0.06 0.056 0.05 0.044 0.044 0.04 0.038 0.033 0.032
R B.P. us 1.02 0.427 1.107 0.578 0.448 0.764 0.503 0.466 0.568 0.524 0.613 0.475 0.483 0.491
S Ac t ive us 15.25 12.8 10.546 11.09 12.8 12.549 11.179 12.8 12.667 11.183 16 12.804 11.235 12.8
T F. P. us 0.35 0.027 0.026 0.023 0.021 0.04 0.019 0.017 0.044 0.015 0.013 0.013 0.011 0.011
S ep era te S y n c
K
H o rizo n tal E Vertic al
B H
Vid e o Vid e o
D F J L
Sync Sync
C A I G
H.Parameters: V.Parameters:
A: Period B: Blanking Time G: Period H: Blanking Time
C: Sync Width D: Back Porch I: Sync Width J: Back Porch
E: Active Time F: Front Porch K: Active Time L: Front Porch
Page 7
B1996NST/NSL
2-4 Display Power Management Signal (DPMS)
Note: These power-saving states exceed the Environmental Protection Agency (EPA) Energy Star
requirements and the Video Electronics Standard Association (VESA) for Display Power
Management Signal (DPMS) .
Table 2-3. Display Power Management Signal (DPMS)
S ta te LED Co lo r H-S y nc V-S y nc Po we r
Co ns umptio n
ON Gre en P ulse P ulse N o rmal
S TAN DBY Yello w N o P ulse P ulse < 1 0 watts
S US P EN D Yello w P ulse N o P ulse < 1 0 watts
OFF Amb e r N o P ulse N o P ulse < 5 watts
2-6 TCO Version (Optional)
The monitor meets the TCO 99, NUTEK energy saving, electric and magnetic field requirements.
2-6-1 TCO 99 Version (Optional)
The emission from magnetic and electric field must comply with the limits specified by the Swedish Board
for Measurement and Testing, commonly known as MPR 1990 recommendations. These limits are
summarized in the Table 2-4.
Table 2-4. TCO 99 Requirements
VL F /T C O E L F /T C O
M a g n e t ic F ie ld 2 5 nT 2 0 0 nT
E le c t r ic F ie ld 1 V/m 1 0 V/m
F r e q ue nc y R a nge 2 ~ 4 0 0 k Hz 5 ~ 2 0 0 0 Hz
Va lu e RM S RM S
D is t a n c e 30 cm 30 cm
E le c t r o s t a t ic
+ /- 5 0 0 V + /- 5 0 0 V
P o t e n t ia l
The monitor is designed with selected CRT and carefully routed wires around CRT, make sure exactly the
same routing scheme is used when doing CRT replacement.
Page 8
B1996NST/NSL
The TCO 99 scheme is for international and environmental labelling of personal computers. The labelling
scheme was developed as a joint effort by the TCO (The Swedish Confederation of Professional Employ
ees), Naturskyddsforeningen (The Swedish Society for Nature Conservation) and NUTEK (The National
Board for Industry and Technical Development in Sweden).
1)`Scope
TCO 95 touches on ergonomic qualities, emissions (electrical and magnetic fields), energy efficiency and
ecology (with demands for environmental adaptation for both the product and the production processes at
the manufacturing plant).
2) Environmental Requirements
The monitor abides by the environmental demands concerning restrictions on the presence and use of
heavy metals, brominated and chlorinated flame retardants, CFCs (freons), and chlorinated solvents,
among other things. The monitor is also recyclable.
3) Energy Requirements
The monitor also follows the energy requirements that, after a certain period of inactivity, the monitor
shall reduce its power consumption to a lower level in one or more stages.
4) Others
The monitor meets the strict environmental demands for the reduction of electric and magnetic fields,
physical and visual ergonomics and good usability.
Table 2-5. TCO 95 Visual Ergonomics
F e a t u re S t a n d a rd D e s c ri p t i o n
L in e a r it y 1 % o r le s s D if f e r e n c e in le n g t h o f c o lu mn s o r r o w s c o mp a r e d t o t h e
c o r r e s p o n d in g le n g t h s t h r o u g h t h e c e n t e r o f t h e mo n it o r .
D is p la y L u min a n c e 1 0 0 c d / m2 ( a t le a s t )
L u min a n c e 1 . 5 :1 o r le s s T h e r a t io is b e t w e e n t h e ma x t o min lu min a n c e w it h in t h e
U n if o r mit y w h o le a c t iv e a r e a .
C o lo r t e mp e r a t u r e