Service Manual
19-inch Color Monitor
C1996NSL/NST/PNST
Service Manual Versions and Revision
No. Version Release Date Revision
1. 1.0 Dec. 5, 2001 Original release
Copyright
Copyright 2001 LiteOn Technology Corp.
All Rights Reserved
This manual may not, in whole or in part, be
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.
Trademarks
LiteOn is a registered trademark of LiteOn
Technology Corp.
All other trademarks are the property of their
respective owners.
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
1-1-1 Warnings
1. For safety purpose, do not attempt to modify
the circuit board, and always disconnect the AC
power before performing servicing on the
monitor.
2. Operation of the monitor outside its cabinet or
with the cover removed involves the risk of
shock hazard. Repair work on the monitor
should only be attempted by service personnel
who are thoroughly familiar with all necessary
safety precautions and procedures for working
on high voltage equipment.
3. Do not lift the CRT by the neck. After
completely discharging the high voltage anode,
handle the CRT only when wearing shatterproof
goggles. Try to keep the CRT away from the
body during handling.
4. High voltage should always be kept at the rated
value, no higher. Only when high voltage is
excessive are X-rays capable of penetrating the
shell of the CRT. Operation at high voltages
may also cause failure of the CRT or high
voltage circuitry.
nonmetallic control knobs, insulating materials,
cabinet backs, adjustment and compartment
covers or shields, isolation resistor-capacitor
networks, mechanical insulators, etc.
3. AC Leakage Current Check
Always perform the AC Leakage Current
Check on the exposed metal parts, including
metal cabinets, screwheads and control shafts,
as follows:
a) Plug the AC line cord directly into a rated
AC outlet. Do not use an isolation
transformer during the check.
b) Use an AC voltmeter with at least 5000
ohms per volt sensitivity as follows:
Connect a 1500 ohms, 10 watt resistor
paralleled by a 0.15uF AC capacitor in series
with all exposed metal cabinet parts and a
known earth ground, such as electrical
conduct or electrical ground connected to
earth ground, as shown in the Figure 1-1.
Measure the AC voltage across the
combination of resistor and capacitor.
Figure 1-1. Set Up For AC Leakage Current Check
5. The CRT is especially constructed to limit Xray emission to 0.5mR/HR at 300 microamperes
anode current. To ensure continued X-ray
protection, replace the CRT with only the same
or equivalent type as the original, and adjust the
anodes voltage to the designated maximum
rating, never to exceed.
1-1-2 Safety Checks
Before returning the monitor to the user, perform
the following safety checks:
1. Inspect to make certain that each lead dress is
not pinched or that hardware is not lodged
between the chassis and other metal parts in
the monitor.
2. Inspect all protective devices such as
Page 2
To kno w n
earth ground
0.15ufd
1500 ohm 10 watt
To exposed m e tal
cabinet part
c) Reverse the AC plug at the AC outlet and
repeat the steps for AC voltage
measurements for each exposed metal part.
d) Voltage reading must not exceed 0.3 volts
RMS, equivalent to 0.2 milliampere AC. Any
value exceeding this limit ill constitute a
potential shock hazard and must be
corrected immediately.
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
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.
C1996NSL/NST/PNST
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
Picture Tube
Scanning Frequency VGA, Super VGA, 1024x768@75/85 Hz, 1280x1024@85 Hz
Maximum Resolution 1600 dots (H) x 1200 lines (V) @75Hz refresh rate
Display Area 350 mm (H) x 262 mm (V) typical
Display Characters 80 char. x 60 rows on a 10 x 10 matrix
deflection, dot type black matrix, medium short persistence
phosphor, dark tint, non-glare/ anti-static screen,
0.26 mm dot pitch
Display Colors Analog
Input
Synchronizatin Signals Separate Sync: horizontal/vertical, TTL, positive or negative
Synchronization
Frequencies
Signal Connectors 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 Center Area : <
User Controls
Service Controls PWB-1596/1598 : power voltage adjust (VR801)
Preset Modes 10 (see Table 2-2. Timing Chart)
Unlimited Color s
Horizontal : 30 to 96 kHz
Vertical : 50 to 160 Hz
0.3 mm; Corner Area : < 0.4mm
Power On/O ff, C ontrast, Brightness, Horizontal Size,
Horizontal Position, Vertical Size, Vertical Position,
Pincushion, Trapezoid, Pin Balance, Parallelogram, Rotation,
Color temperature, Language, Display Frequency, Degauss,
Recall, H. Moire, V. Moire
focus 1 , focus 2
Environmental
Considerations
Operation temperature : 5
Operation Humidity : 20% to 80% ambient
Storage temperature : -40
Storage Humidity : 5% to 95% (non-condensing)
Altitude : up to3000m above sea level
o
C to 35oC ambient
o
C to 65oC ambient
Note: Above specifications are subject to change without prior notice.
Page 5
2-2 Signal Cable Pin Connections
Table 2-1. Signal Cable Pin Assignment
Pin Signal Pin Signal
1Red video 9 +5V
2 Green video 10 Digital Ground
3 Blue video 11 Ground
4 Ground 12 SDA
5* Ground 13 H- Sync
6 Red ground 14 V- Sync/VC L
7 Green ground 15 SCL
8 Blue ground
C1996NSL/NST/PNST
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
Mode 12345678910
H. Dots 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-fre q (kHz) 31.47 37.927 43.27 49.725 53.67 68.681 68.67 75 91.146 93.75
Sync Polarity -- - - + -+ -++
A pe riod us
B Bla nking us 6.356 6.085 5.33 5.586 4.409 3.04 3.725 3.457 2.844 2.765
C Sync us 3.81 2.028 1.556 1.117 1.138 1.28 1.016 1.185 1.016 0.948
D B.P. us 1.907 3.042 2.22 3.91 2.702 1.44 2.201 1.877 1.422 1.501
E Active us 25.42 20.282 17.78 14.524 14.222 11.52 10.836 9.877 8.127 7.901
F F. P. us 0.636 1.014 1.556 0.559 0.569 0.32 0.508 0.395 0.406 0.316
V-freq (Hz) 59.94 85 85 74.55 85 75.062 84.99 60 85 75
Sync Polarity -+ - - + - + - ++
G Period ms 16.68 11.759 11.76 13.414 11.756 13.322 11.765 16.667 11.761 13.333
H Blanking ms 1.43 1.213 0.67 0.864 0.578 0.656 0.582 0.667 0.527 0.533
I Sync ms
J B.P. us 1.02 1.107 0.578 0.764 0.503 0.568 0.524 0.613 0.483 0.491
K Active us 15.25 10.546 11.09 12.549 11.179 12.667 11.183 16 11.235 12.8
L F.P. us 0.35 0.026 0.023 0.04 0.019 0.044 0.015 0.013 0.011 0.011
31.78 26.366 23.11 20.11 18.631 14.561 14.561 13.333 10.971 10.667
0.064 0.079 0.069 0.06 0.056 0.044 0.044 0.04 0.033 0.032
Seperate Sync
Horizontal
C
E
Vid eo
D
Sync
A
B
F
H.Parameters:
A: Period B: Blanking Time
C: Sync Width D: Back Porch
E: Active Time F: Front Porch
Ve r ti c a l
I
K
Vid eo
J
Sync
G
H
L
V.Parameters:
G: Period H: Blanking Time
I: Sync Width J: Back 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
LE
State Power
Consumption
ON <120 watts Green
D
Light
Active
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.
<3 watts Amber
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
Page 8
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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
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Page 9
3 Control Location and Functions
C1996NSL/NST/PNST
12
(1) (2)
(3) (4)
(5) (6)
(1) Function Key
(2) Decrease Key
(3) Increase Key
(4) Select Key
(5) Power LED
(6) Power ON/OFF
3-1 Front Panel
3-2 Front Panel Keys Functions
1. Function Key: Display the main menu, and exit the adjustment screen and save adjustments.
2. Decrease Key: Scroll across main menu, highlighting control to be adjusted. Decrease value of selected
control. Toggle between Contrast and Brightness adjustment screens.
3. Increase Key: Scroll across main menu, highlighting control to be adjusted. Increase value of selected
control. Toggle between Contrast and Brightness adjustment screens.
4. Select Key: Press once to display adjustment screen. Press again, for some controls, to toggle between
controls shown in pairs on main menu.
5. Power LED: Display different modes (ON, OFF) of the monitor by showing different color for each
mode.
6. Power ON/OFF: To turn the monitor ON and OFF.
3-3 Adjustment Procedure
1. Press (6) key to turn on the monitor.
2. At normal condition, press (1)on the front panel to activate the on-screen manager (OSM) menu.
3. To select a user control, press (2) or (3) key repeatedly until the control is highlighted.
4. To adjust the value for a particular control, press (4), then press the (2) or (3) key to obtain the desired
value. There are a few parameters that do not require any adjustment, like Manual Degauss, Memory
Recall.
5. Some controls are grouped in pairs on the main menu. Press (4) key to toggle between them.
6. To save your adjustments and exit screen, press (1) key. The menu will automatically clear out from the
screen if no keys are pressed within 30 seconds.
Note: To enter the Internal Adjustment mode, press (1) & (4) keys simultaneously then press (6).
Page 10
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