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Service Manual
19-inch Color Monitor
C1996NSL/NST/PNST
Service Manual Versions and Revision
N o. Ve rs ion R e le as e D ate R e vis ion
1. 1.0 Dec. 5, 2001 Original release
Copyright Trademarks
Copyright 2001 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.
C1996NSL/NST/PNST Service Manual.
Printed in Taiwan.
C1996NSL/NST/PNST
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
C1996NSL/NST/PNST
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
or equivalent type as the original, and adjust the ea rth g ro un d ca bin et p art
0.15 ufd
anodes 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
C1996NSL/NST/PNST
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 instruments ground lead to the instrument chassis ground before connecting the
positive lead; always remove the instruments 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
C1996NSL/NST/PNST
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
C1996NSL/NST/PNST
2 Product Specifications
2-1 Specifications
19- inch, (18- inch visual image area) sloted mask , 90 degrees
P icture Tub e deflectio n, dot type black matrix, medium short persistence
phosphor, dark tint, no n- glare/ anti- static screen,
0 . 2 6 mm d ot p itch
Scanning Fre quency VGA, S up er VGA, 1 0 2 4 x76 8 @ 7 5 /8 5 Hz, 1 2 8 0 x1 0 2 4 @ 8 5 Hz
Maximum Reso lutio n 1 6 0 0 d o ts (H) x 1 20 0 lines (V) @ 7 5 Hz refresh rate
Disp lay Are a 3 5 0 mm (H) x 26 2 mm (V) typ ical
Display C haracters 80 char. x 60 ro ws on a 10 x 10 matrix
Display C o lors Analog
Unlimited C o lo rs
Input
S ynchronizatin S ignals S ep arate S ync: ho rizo ntal/vertical, TTL, p o sitive o r negative
S ynchronizatio n Ho rizo ntal : 30 to 96 kHz
F requencies Vertical : 50 to 160 Hz
Signal C o nnectors 15- pin, D- shell connector
Video Signals Analog : 0.7 Vp- p, RGB positive
Power Input 120 Watts (maximum) AC rated voltage, 100VAC to 240VAC
Misconvergence C enter Area : < 0.3 mm; C o rner Area : < 0 . 4 mm
P o wer O n/O ff, C ontrast, Brightness, Horizontal S ize,
Horizontal P o sition, Vertical S ize, Vertical P o sition,
User C ontro ls
P incushion, Trapezoid, P in Balance, P arallelogram, Ro tation,
C o lo r temp erature, Language, Display F req uency, Degauss,
Recall, H. Mo ire, V. Moire
Service C ontro ls PWB- 1596/1598 : power voltage adjust (VR801)
fo cus 1 , fo cus 2
P reset Modes 10 (see Table 2- 2. Timing C hart)
Environmental O p eration temp erature : 5 o C to 35 o C ambient
C onsideratio ns O p eration Humidity : 20% to 80% ambient
S torage temp erature : - 40 o C to 65 o C ambient
Storage Humidity : 5% to 95% (non- condensing)
Altitude : up to3000m above sea level
Note: Above specifications are subject to change without prior notice.
Page 5
C1996NSL/NST/PNST
2-2 Signal Cable Pin Connections
Table 2-1. Signal Cable Pin Assignment
Pin S ig na l Pin S ig na l
1 Re d vid e o 9 +5V
2 Gre e n vid e o 10 Digita l Gro und
3 Blue vid e o 11 Gro und
4 Gro und 12 S DA
5* Gro und 13 H- S ync
6 Re d gro und 14 V- S ync /VC L
7 Gre e n gro und 15 SCL
8 Blue gro und
Note: * This pin is used for selftest detection. Connect this pin to ground at the PC end.
Page 6
C1996NSL/NST/PNST
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
M o de 1 2 3 4 5 6 7 8 9 10
H . D ots 640 720 640 832 800 1152 1024 1600 1280 1600
V. D o t s 480 400 480 624 600 870 768 1200 1024 1200
H - f r e q ( k H z) 31.47 37.927 43.27 49.725 53.67 68.681 68.67 75 91.146 93.75
S y n c P o la rit y - - - - + - + - + +
A pe rio d us 31.78 26.366 23.11 20.11 18.631 14.561 14.561 13.333 10.971 10.667
B B la nk ing us 6.356 6.085 5.33 5.586 4.409 3.04 3.725 3.457 2.844 2.765
C S y nc us 3.81 2.028 1.556 1.117 1.138 1.28 1.016 1.185 1.016 0.948
D B . P. u s 1.907 3.042 2.22 3.91 2.702 1.44 2.201 1.877 1.422 1.501
E A c tiv e us 25.42 20.282 17.78 14.524 14.222 11.52 10.836 9.877 8.127 7.901
F F. P. u s 0.636 1.014 1.556 0.559 0.569 0.32 0.508 0.395 0.406 0.316
V - f r e q ( H z) 59.94 85 85 74.55 85 75.062 84.99 60 85 75
S y n c P o la rit y - + - - + - + - + +
G P e ri o d m s 16.68 11.759 11.76 13.414 11.756 13.322 11.765 16.667 11.761 13.333
H B la nk ing ms 1.43 1.213 0.67 0.864 0.578 0.656 0.582 0.667 0.527 0.533
I S y nc ms 0.064 0.079 0.069 0.06 0.056 0.044 0.044 0.04 0.033 0.032
J B . P. u s 1.02 1.107 0.578 0.764 0.503 0.568 0.524 0.613 0.483 0.491
K A c tiv e us 15.25 10.546 11.09 12.549 11.179 12.667 11.183 16 11.235 12.8
L F. P. u s 0.35 0.026 0.023 0.04 0.019 0.044 0.015 0.013 0.011 0.011
Seperate Sync
Horizontal E Vertical K
B H
Video Video
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
C1996NSL/NST/PNST
2-4 Power Saving Function
Note: The monitor will be driven into Power Saving mode by the control signal from the display
controller, as indicated by the amber-color power LED.
Table 2-3. Power Saving Function
S ta te Po we r LE D
Co ns umptio n Lig ht
ON < 1 2 0 watts Gre en
Active
< 3 watts Amb e r
OFF
The power saving states will be kept until a control signal has been detected or the keyboard or mouse is activated.
The recovery time from Active OFF state back to ON state is around 10 seconds.
2-5 TCO Version (Optional)
The monitor meets the TCO 99, NUTEK energy saving, electric and magnetic field requirements.
2-5-1 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
Page 8
C1996NSL/NST/PNST
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.
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 99 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 99 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