LITE-ON B1770FNS Service Manual

Service Manual

17-inch Color Monitor
B1770FNSL/FNST

Service Manual Versions and Revision

No. Ve rsion Re le as e Dat e Re vision

1. 1.0

July

3

1, 2000

Original release

Copyright

Copyright 2000 LiteOn T echnology 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
T echnology Corp.

B1770FNSL/FNST Service Manual.

Printed in Taiwan.

T rademarks

LiteOn is a registered trademark of LiteOn
T echnology Corp.

All other trademarks are the property of their
respective owners.

B1770FNSL/FNST

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

B1770FNSL/FNST

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 CR T 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
anode’s 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 ex posed 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.

B1770FNSL/FNST

1-1-3Product 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

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 T est

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.

B1770FNSL/FNST

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 T ester 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

2 Product Specifications

2-1 Specifications

17-inch (16 inch Visual image area), sloted mask, 90 degrees

OMPicture Tube

deflection, dot type black matrix, medium short persistence

phosphor, dark tint, non-glare/ anti-stati c screen,

0.25 mm dot pitch, flat screen.

B1770FNSL/FNST

Sc anning Fre quenc y

Maximum Resolution 1280 dots (H) x 1024 lines (V) @60Hz refresh rate
Display Area 306 mm (H) x 230 mm (V) typical
Display Characters 80 char. x 60 rows on a 10 x 10 matrix
Display Col ors Analog

Input
Synchronizatin Signals Separate Sync: horizontal/vertical, TTL, positive or negative
Synchronization

Fr eq ue nci e s
Si gnal Conne cto rs 15 -pi n, D- she ll connector
Video Signals Anal og : 0.7 Vp-p, RGB positive
Power Input 95 Watts (maximum) AC rated voltage, 100VAC to 240VAC
Misconvergence Center Area : <

User C ont ro ls

VGA, Super VGA, 1024x768@60/70/75/85 Hz,

1280x1024@60 Hz

Unl imit ed Co lo rs

Horizontal : 30 to 70 kHz
Vertical : 50 to 160 Hz

0.3 mm; Corner Area : < 0.4mm

Power On/Off, Contrast, Brightness, Horizontal Size,
Horizontal Position, Vertical Size, Vertical Position,
Pincushion, Trapezoid, Rotation, Color temperature,
Language, Dis play Fr eque ncy, Dega uss, Reca ll, H. Moire ,
V. M o i r e

Service Controls PWB-1533 : R-bias (VR901), G-bias (VR931),

B-bi as (VR961),
PWB-1518 : power voltage adjust (VR801),

high voltage adjust (VR401), focus1, focus2
Preset Modes 11 (see Table 2-2. Timing Chart)
Environmenta l

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 40oC 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 Sig nal Pin Signal

1 Red video 9** PC
2 Green video 10 Digital Ground
3 Blue video 11 Ground

4Ground 12SDA
5* NC 13 H-Sync
6 Re d ground 14 V-S ync/ VCL
7 Green gr ound 15 SCL
8 Bl ue gr ound

B1770FNSL/FNST

Note: * This pin is used for selftest detection. Connect this pin to ground at the PC end.

** For PC99 : this pin will provide +5V from PC side.

Page 6

B1770FNSL/FNST

2-3 Timing Chart

This section describes the timings that the computer industry recognizes as standard for computer-generated
video signals.

T able 2-2. Timing Chart

Mode 1 2 3 4 5 6 7 8 9 10 11

H. Dot s

V. D o t s

H-fre q (kHz)

Sync
Polarity

A pe riod us

B Blking us

C S ync us

D B.P. us

E Active us

F F. P. us

V-fre q (Hz)

Sync
Polarity

O Period ms

720 640 800 640 640 800 1024 800 1024 1280 1024

400 480 600 480 480 600 768 600 768 1024 768

31.47 31.47 37.88 37.5 43.3 46.8 48.36 53.67 60.02 64.34 68.68

--+ - - + + + +++

31.78 31.78 26 .4 26 .666 23.111 21.333 20.68 18.63 16.6 6 15.55 14.56

6.356 6.356 6.4 6.35 5.33 5.17 2 4.923 4.40 9 3.65 7 3. 589 3.72 5

3.81 3.81 3.2 2.03 1.556 1.616 2.092 1.138 1.219 0.972 1.016

1.907 1.907 2.2 3.81 2.222 3. 232 2.462 2.702 2.235 2.248 2.201

25.42 25.42 20 20.32 17.778 16.162 15.75 14.22 13 11.96 10.836

0.636 0.636 1 0.51 1.556 0.323 0.369 0.569 0.203 0.374 0. 508

70.08 59.95 60.32 75 85 75 60 85 75.03 60 85

+-+ - - + + + +++

14.27 16.68 16.58 13.33 11.764 13.333 16.67 11.76 13.33 16.67 11.77

P Blking ms

Q Sync ms

R B.P. us

S Active us

T F.P. us

1.557 1.43 0.739 0.533 0.67 0.533 0. 786 0.578 0.533 0.642 0.58 2

0.064 0.064 0.106 0.08 0.069 0.06 4 0.124 0.056 0.05 0.047 0.044

1.08 1.02 0.607 0. 427 0.578 0.44 8 0.6 0.503 0.466 0.501 0.524

12.71 15.25 15.84 12.8 11.093 12.8 15.88 11.18 12.8 16.03 11.18

0.413 0.35 0.026 0.026 0.023 0.02 1 0.062 0.019 0.017 0.094 0.015

Seperate Sync

Horizontal

C

E

Video

D

Sync

A

B

F

H.Parameters:

A: Period B: Blanking Time
C: Sync Width D:Back Porch
E : Active Time F : Front Porch

Ver tic a l

I

K

Video

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

B1770FNSL/FNST

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) .

T able 2-3. Display Power Management Signal (DPMS)

State LED Color H-Sync V-Sync Power

Co nsumpt io n

ON Gre en Puls e Puls e No rma l

STANDBY Yellow No Pulse Pulse <15 wa tts

SUSPEND Yellow Pulse No Pulse <15 watts

OFF Amber No Pulse No Pul se <5 watts

2-6 TCO Version (Optional)

The monitor meets the TCO 92, NUTEK energy saving, electric and magnetic field requirements. Also it
is compliant with TCO 95/TCO 99 labelling scheme.

2-6-1TCO 92 Version (Optional)

The emission from magnetic and electric field must comply with the limits specified by the Swedish Board
for Measurement and T esting, commonly known as MPR 1990 recommendations. These limits are
summarized in the T able 2-4.

T able 2-4. TCO 92 Requirements

OCT/FLVOCT/FLE

dleiFcitengaMTn52Tn002

dleiFcirtcelEm/V1m/V01

egnaRycneuqerFzHk004~2zH0002~5

eulaVSMRSMR

ecnatsiDmc03mc03

citatsortcelE

laitnetoP

V005-/+V005-/+

The monitor is designed with selected CRT and carefully routed wires around CRT, make sure exactly the
same routing scheme is used when doing CR T replacement.

Page 8

B1770FNSL/FNST

2-6-2TCO 95 Version (Optional)

The TCO 95 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 T echnical 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

erutaeFdradnatSnoitpircseD

ytiraeniLsselro%1 ehtotderapmocsworrosnmulocfohtgnelniecnereffiD

ecnanimuLyalpsiD)tsaelta(2m/dc001

ecnanimuL
ytimrofinU

sselro1:7.1 ehtnihtiwecnanimulnimotxamehtneewtebsioitarehT

.aeraevitcaelohw

2-6-3TCO 99 Version (Optional)

TCO 99 will append the color temperature specification.

.rotinomehtforetnecehthguorhtshtgnelgnidnopserroc

Page 9

3 Control Location and Functions

(1) (2) (3) (6)(5)(4)

3-1 Front Panel

B1770FNSL/FNST

(1) Function Key
(2) Decrease Key
(3) Increase Key
(4) Select Key
(5) Power LED
(6) Power ON/OFF

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, Standby, Ssuspend or 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: T o enter the “Internal Adjustment” mode, press (1) & (4) keys simultaneously then press (6).

Page 10