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Service Manual
A1454 / A1554NEL
Color Monitor
Service Manual Versions and Revision
N o. Ve rs ion R e le as e D ate R e vis ion
1. 1.0 May 28, 1998 O riginal release
2 1.1 June 19, 1998 4-1-3 (3)
4-2-2 Screen and White Balance Adjustment
6 (15) update model
6 (16) add spare parts
3 1.2 July 8, 1998 2-6 DPMS (Page 9)
3 (Page 10)
Copyright Trademarks
Copyright 1998 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.
A1454 / A1554 NEL Service Manual.
Printed in Taiwan.
A1454 / A1554 NEL
Table of Contents
1. Precautions ................................................................................................. 2
2. Product Specifications .............................................................................. 5
3. Operation Theory ...................................................................................... 9
4. Alignments and Adjustments .................................................................... 13
5. Troubleshooting......................................................................................... 17
6. Recommended Spare Parts List ................................................................ 21
7. Block Diagram .......................................................................................... 23
8. Exploded Diagrams ..................................................................................... Inserted
9. PCB Diagrams ............................................................................................ Inserted
10. Schematic Diagrams ................................................................................... Inserted
1
A1454 / A1554 NEL
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 tal
ca bin et part
or equivalent type as the original, and adjust the earth g ro und
0.15 ufd
anode's voltage to the designated maximum
rating, never to exceed.
15 00 o hm 1 0 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.
2 Precautions
A1454 / A1554 NEL
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.
Precautions 3
A1454 / A1554 NEL
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.
4 Precautions
A1454 / A1554 NEL
2 Product Specifications
2-1 Specifications
Pi cture Tube 14-i nch ( 13.3- inch Vi sual i mage ar ea) ,
15-i nch ( 14.0- inch Vi sual i mage ar ea)
sl oted mask, 9 0 degrees defl ecti o n, d ot type bl ack matr ix, medi um sho rt
per si stence phosphor, dar k ti nt, no n- glar e/ anti - stati c screen, 0.28 mm dot
p itch
Scanning Frequency VGA, Super VGA, 80 0x600@60 / 72/75/85 Hz, 1024x7 68 @60 Hz
Maxi mum Resol ution 1024 do ts (H) x 768 l i nes ( V) @60Hz refresh rate
Di splay Ar ea 14-i nch 250 mm (H) x 187 mm ( V) typical
15-i nch 262 mm (H) x 196 mm ( V) typical
Di splay Characters 8 0 char. x 60 row s on a 10 x 10 matr i x
Di sp lay Co l or s Anal o g Input Unl i mi ted Col or s
Synchroni zati n Si gnal s Sep ar ate Sync: ho ri zontal /v erti cal , TTL, po siti v e o r negati ve
Ho ri zo ntal : 30 to 54 kHz
Synchroni zati on Freq uenci es
Verti cal : 5 0 to 12 0 Hz
Si gnal Co nnecto rs 1 5-p i n, D-shell connecto r
Vi deo Si gnals Anal og : 0 .7 Vp-p , RGB p osi ti ve
Po w er Inp ut 1 4-i nch 7 0 Watts ( nominal ) AC r ated voltage, 10 0VAC to 26 4VAC
1 5-i nch 7 5 Watts ( nominal ) AC r ated voltage, 10 0VAC to 26 4VAC
Misconvergence Center Area : < 0.3 mm; Corner Area : < 0.4 mm
User Co ntrols Po w er On/ Off, Contrast, Bri ghtness, Verti cal Si zs, Verti cal Po si tion,
Ho ri zo ntal Pos iti on, Ho ri zo ntal Si ze, Pi ncushi on, Tr apezoid,
Servi ce Control s PWB- 14 02 : R- bi as (VR9 10 ), G- bi as (VR9 40 ), B-bias (VR970) ,
R-gain (VR59 9) , G-gain (VR5 98 )
PWB- 14 05 : po w er vo l tage adj ust ( VR8 01 ), high vo ltage ad j ust ( VR80 2) ,
, fo cus
Pr es et Modes 1 2 (see Tabl e 2-2. Timi ng Char t)
Envi ronmental Consi der ati o ns Op erati on temper atur e : 5 o C to 40 o C ambi ent
Storage temp erature : 0 oC to 65 o C ambi ent
Humidity : 5% to 95% ambi ent
Sto rage Humi di ty : 5% to 95 % (no n- cond ensi ng)
Al ti tude : up to 30 00 m abo ve sea l evel
Note: The above specifications are subject to change without prior notice.
Product Specifications 5
A1454 / A1554 NEL
2-2 Signal Cable Pin Connections
Table 2-1. Pin Assignments
Pin Sig na l Pin Sig na l
1 Red video 9 N o pin
2 Green vid eo 10 Digital Ground
3 Blue video 11 Ground
4 Ground 12 SDA
5* Selftest 13 H- Sync
6 Red gro und 14 V- Sync/VC L
7 Green ground 15 SC L
8 Blue ground
Note: * This pin is used for selftest detection. Connect this pin to ground at the PC end.
6 Product Specifications
A1454 / A1554 NEL
2-3 Timing Chart
This section of the service manual describes the timing 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
H. Dots 720 720 640 640 640 800 800 800 800 640 1024 800
V. Dots 350 400 480 480 480 600 600 600 600 480 768 600
H-freq (kHz) 31.47 31.47 31.47 37.86 37.5 35.16 37.88 46.875 48.08 43.3 48.36 53.674
Sync Polarity + - - - - +/- + + + - - +
A Period us 31.78 31.78 31.78 26.413 26.666 28.44 26.4 21.333 20.8 23.11 20.677 18.6
B Blking us 6.356 6.356 6.356 6.095 6.35 6.22 6.4 5.172 4.8 5.333 4.923 4.409
C Sync us 3.81 3.81 3.81 1.27 2.07 2 3.2 1.616 2.4 1.556 2.09 1.138
D B.P. us 1.907 1.907 1.907 4.06 3.81 3.556 2.2 3.232 1.28 2.222 2.462 2.702
E Active us 25.42 25.42 25.42 20.317 20.32 22.22 20 16.162 16 17.778 15.75 14.222
F F.P. us 0.636 0.636 0.636 0.76 0.51 0.667 1 0.323 1.12 1.556 0.369 0.569
V-freq (Hz) 70.08 70.08 59.95 72.81 75 56.25 60.32 75 72.18 85 60 85
Sync Polarity - + - - - +/- + + + - - +
G Period ms 14.27 14.27 16.68 13.735 13.33 17.78 16.58 13.333 13.87 11.764 16.67 11.8
H Blking ms 3.146 1.557 1.43 1.057 0.533 0.711 0.739 0.533 1.373 0.67 0.786 0.578
I Sync ms 0.064 0.064 0.064 0.079 0.08 0.057 0.106 0.064 0.125 0.069 0.124 0.056
J B.P. ms 1.87 1.08 1.02 0.74 0.407 0.626 0.607 0.448 0.478 0.578 0.6 0.503
K Active ms 11.12 12.71 15.25 12.678 12.8 17.07 15.84 12.8 12.51 11.093 15.88 11.179
L F.P. ms 1.21 0.413 0.35 0.238 0.026 0.0284 0.026 0.021 0.770 0.023 0.062 0.019
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
Product Specifications 7
A1454 / A1554 NEL
2-4 Display Power Management Signaling (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 Signaling (DPMS) .
Table 2-3. Display Power Management Signaling (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 5 watts
S US P EN D Yello w P ulse N o P ulse < 1 5 watts
OFF Amb e r N o P ulse N o P ulse < 5 watts
8 Product Specifications
A1454 / A1554 NEL
3 Operation Theory
This is a fully digital multi-sync color monitor that is compliant with DDC1 and 2B Plug and Play VESA
standard and offers the following main features.
3-1 Main Features
1. Simplified design with minimum components.
2. The NOVATEK NT68P61A processor-- that has I2C BUS controlled geometric correction, contrast and
brightness-- offers the functions for: (a) Contrast, (b) Brightness, (c) H-size, (d) H-position, (e) V-size, (f)
V-position, (g) Pincushion, and (h) Trapezoid.
In addition, it also offers more functions as: (a) Sync. processor, I/P and O/P, (b) Mute, (c) Power saving
- Suspend & Stand-By, (d) Power saving override, (e) DDC1/2B, (f) I2C Bus for auto-alignment through
signal cable (g) CS1/CS2 for linearity and size compensation.
3. Stores up to 12 factory preset modes and offers 6 user modes. Recall factory modes by pressing together
"+" and "-" keys from the front panel. Use "Select" key to select a parameter and "+" and "-" for
adjusting the value of the parameter. User setting data are stored automatically.
4. Powerful PHILIPS TDA4853 and TDA4866 present the following useful functions: (a) Pincushion, (b)
Trapezoid, (c) V-Position, (d) V-Size, (e) Vertical's "C" and "S" correction -- factory adjust, (f) Pincushion's
V. position correction, (g) Corner correction -- factory adjust, (h) Pincushion unbalance correction --
factory adjust, (i) Parallelogram distortion -- factory adjust, (j) Moire cancellation -- factory adjust, (k) X-
ray protection, and (l) Full horizontal plus with vertical auto sync capability.
5. Software controlled auto shut off function activated if fH < = 29 kHz and fH > = 56 kHz.
6. Full range AC input and simplified line filter design.
3-2 Microcontrol Section
1. This monitor uses NOVATEK NT68P61 CPU. It contains a 6502 8-bit CPU core, 256 bytes of RAM
used as working RAM and stack area, 24k bytes of OTP ROM, 14-channel 8 bit PWM D/A converter,
2-channel A/D converters for key detection saving I/O pins, internal H. sync and V. sync signals processor
providing mode detection, and an I2C bus interface. When H/V sync through D-Sub signal cable enter pin
39 and pin 40, the CPU marks frequency polarity detection and calculate and send to H/V sync OUT.
Then CPU reads the data from I703 and write to device 4854 and some DAC in CPU. the above
operation takes about 500 ms.
2. There are 12 factory preset modes and 6 user modes. There are 8 functions, Contrast, Brightness, H.
Size, H. Position, V. Size, V. Position, Pincushion, and Trapezoid, all controlled by panel keys which can
be adjusted by user.
3. The user control parameters are selected in sequence listed as above by LEDs. When pressing "select",
the function will be selected one by one. When a particular parameter is chosen, use "+" and "-" button
to adjust the value. LED will flash when reaching extreme value, which means the value cannot be
increased or decreased anymore. There are seven functions which can be controlled only by internal
setting. Through internal setting user can modify the factory preset data.
4. The pin 24 and pin 25 are used for ATE and DDC function. The DDC1 and DDC2 are implemented in
CPU. When power on the CPU is initial in DDC1 mode. At DDC1 mode when V. sync in, the data will
be sent out one by one. When SCL is lowized, the CPU will enter the DDC2 mode. In DDC2 mode, after
receiving A0 0 A1, the EDID data will be sent out. When CPU receive C6 as slave address, the CPU will
operate in ATE mode which is used for auto-alignment. After alignment the data will be stored in I703.
Operation Theory 9
A1454 / A1554 NEL
3-3 Deflection Section
1. I2C -- autosync deflection controller is TDA4853.
2. The TDA4853 is a high performance and efficient solution for autosync monitors. All functions are
controllable by I2C bus. SDA and SCL signals come from microprocessor feed to pin 19 and pin 18 to
control all functions.
3-3-1 Horizontal Section
1. The oscillator is driven by the currents in R419 and R420. The minimum oscillator frequency is determined
by R419 and the maximum frequency is determined by R420.
2. Horizontal sync comes into pin 15 through R318. And horizontal flybok pulse comes into pin 1 through
R401, R402 and by pass filter C403 from pin 6 of FBT for AFC loop.
3. Horizontal driver (pin8) O/P to Q401 via C410.
3-3-2 Vertical Section
1. Vertical sync comes into pin 14 through R317.
2. The free running frequency is determined by R301 and C301.
3-3-3 Vertical O/P section
1. The differential output currents from pin 13 of Vout1 and pin 12 of Vout2 can be directly coupled to the
vertical deflection booster pin 1 and pin 2 of TDA4866.
2. The TDA4866 has two output stages which are current driven in opposite phase and operate in combination
with the deflection coil in a full bridge configuration.
3-3-4 E-W/Trapezoid and H. Width Controls
1. The horizontal O/P stage uses diode modulator D419, D423, C411, C412, L409 and C418 for East-West
(Pincushion) Trapezoid and H. width controls.
2. The scan current is determined by B+ minus Vm ( the voltage of C418) values and the pincushion control
is accomplished by Darlington pair Q418 and Q419 by coupling a parabola waveform from pin 11 of
TDA4853. The H. width size corner correction and trapezoid are also accomplished by this pin 11.
3-3-5 X-Ray Protection
1. To avoid X-ray hazard, a DC voltage generated by pin 6 of FBT and rectified by D408, C432 and divided
by R403, R404 and R405 come into pin 2 of TDA4853.
2. If this voltage is higher than 6.39 V, then TDA4853 will be activated to float HUNLOCK (pin17), H. DRV(
pin 8), B DRV (pin 6), VOUT1 (pin 12), VOUT2 (pin13). After that all deflection circuit stop working.
3-3-6 G1, Blanking and Brightness
1. The vertical blanking signal comes from two ways. One is from pin 8 of I301 (TDA4866), the other is
from vertical sync (pin 32 of I701). This two positive vertical pulses through Q406 amplified and converted
into negative pulse and sent to G1 for vertical blanking.
2. In protection mode or an out of range situation HUNLock will send 5 V pulse to saturate Q405 and open
Q408 then G1 will go down to -140V. During the mode change, Mute acts as same as HUNLock's.
3. The brightness is controlled by CPU pin 1 comes into PNP transistor Q408, low voltage causes high
10 Operation Theory
A1454 / A1554 NEL
current to get brighter raster, high voltage gets lower brightness.
3-4 Power Supply Section
3-4-1 AC Rectifier
The circuit can accept 90 V to 264 V AC input through D801~D804 bridge diodes and C808 filtering to get
DC 126 V~364 V for power conversion in T802.
3-4-2 Line Filter
It consists of C801, C802, C803, C816 and T801 and meets EMI regulation.
3-4-3 Power LED Status
1. The LED has 3 leads common cathode with green and amber colors for different power saving indications.
It is controlled by CPU.
2. Normal : Green light
Amber LED is off because CPU pin10 is high and pin 9 is low, only green LED is turned on.
3. Standby / Suspend : Yellow light
CPU pin 9 and pin 10 are low, then green and amber LED are turned on. That is yellow.
4. Off Mode : Amber light
CPU pin 9 is high and pin 10 is low, then green is off and amber is on.
3-4-4 Auto Degaussing
1. A1454NEL : When SMPS works, the 6.3 V power source is applied to Q802 and CPU let Q802 turn on
a few seconds, then drive the armature of RL801 to perform the degaussing function.
2. A1554NEL : When power switch S801 on, the AC current flows through R862, D816 (D817) and
degaussing coil preforms the degaussing function.
3-4-5 PWM Control
1. Start Up
The I801 gets power from R807, R817, C812 and pin 7 voltage reaches 16 V for starting up. The I801
starts oscillation at 22 kHz, sawtooth on pin 4 and pin 6 output to drive Q803/T802. Once Q803 switches
on, D806, C804 set up an 15 V to keep I801 working through D808 auxiliary voltage.
2. Regulation
The DC O/P voltage is proportional to the auxiliary voltage, so I801 pin 2 senses the feedback voltage
from the divider R802, R823, VR801 and R821 to compare with built-in 2.5 volts reference voltage for
error amplifier operation. Finally pin 6 can modulate the different duty cycle by VR801 setting to achieve
regulation purpose.
Operation Theory 11
A1454 / A1554 NEL
3-4-6 Synchronization
1. Normal Mode
The sync pulse from FBT (31 kHz~54 kHz) via C815, R826, D824 and R816 to pin 4 of I801 to keep I801
synchronized with horizontal sync input frequency.
2. Power Saving Modes: Standby/Suspend
Because there is no pulse from FBT, so the free-run frequency is decided by R815 and C814 and the
SMPS works at 22 kHz.
3. Override
The horizontal free run frequency is about 41 kHz under override condition, SMPS is synchronized to this
frequency.
3-4-7 O.V.P.
If the auxiliary voltage is higher than zener voltage ZD807 (18 volts) and makes pin 3 of I801 higher than
1 V, pin 6 duty cycle is limited to have the OVP activated.
3-4-8 O.P.P.
The excess current of T802 through R813 can develop enough voltage to pin 3 then limit the power delivered
because the pin 6 duty cycle is limited too.
3-4-9 Step Up Power Supply For FBT
1. The B+ of FBT is proportional to horizontal frequency, that is higher frequency, higher voltage. The basic
voltage is 75 volts from T802 pin 9 via D840, L812 and the gate control of Q807 comes from I401 pin 6 via
Q808, Q809 and Q810. The duty cycle is controlled by C843, C462, R489, R846 and R856, R857, R858
VR802 combination ratio.
2. The regulation and boost up (from 77 V to 92 V or more, on demand). The H.V. is set at 24.5 kV (zero
beam) by VR802 which senses the secondary O/P from FBT. The booster comprises Q807, L801, D820,
C425 and I802 to offer the required B+ for different frequency modes.
3-5 Video Amplifier Section
1. RGB signal inputs are terminated by R502, R532 and R562 then pass through the coupling capacitors
C501, C531 and C561 to the IC501 MM1375 pre-amplifier.
2. The amplifier RGB signals (0~3 Vpp) are adjusted by VR599 (R), VR598 (G). Pin 9 is for DC contrast
control input, pin 11 is for clamp pulse which comes from pin 16 of TDA4853 to set up the equal clamp
level.
3. The video output stages are cascode amplifiers with buffer of complementary emitter followers, the stray
capacitance is so small that the load resistor R906, R911, R936, R941, R966 and R971 can be 3.6 k ohm
and the power dissipation is minimized.
4. The RGB cathodes cut off are adjusted by VR910, VR940 and VR970.
5. Under override condition, the self test signal is supplied from pin 1 of CPU, the default value is about 1
volt. In this condition, G1 will increase 10 volts then get about 6 FL light out put.
12 Operation Theory
A1454 / A1554 NEL
4 Alignments and Adjustments
This section of the service manual explains how to make permanent adjustments to the monitor settings.
4-1 General Adjustments
4-1-1 Adjustment Conditions
a) Power Supply
Apply AC 115 V or 220 V
b) Warm-up Time
The monitor must be powered on for 15 minutes before starting any alignment, but requires 30 minutes of
warm-up time for convergence adjustment.
c) Signal Input
1. Video: RGB Analog, 0.7 Vp-p, positive
2. Synchronization: Horizontal and vertical TTL signal, separate, positive or negative
3. All adjustments should be made using a signal of FH = 31.468 kHz, FV = 60 Hz, unless otherwise
defined.
4-1-2 Equipment Required
The following equipments are necessary for adjustment procedures:
1. Volt-ohm-A meter (Sanwa FD-750C or equivalent)
2. 30 kV high voltage probe (HP34111A)
3. Oscilloscope (TEK2235 or equivalent)
4. Minolta Color Analyzer II
5. Signal generator (IBM PC with proper display cards or Chroma 2000)
6. Screwdriver
4-1-3 Switching Power Supply and Regulator Adjustment
The regulated B+ control has been preset in the factory and needs no adjustment. However, if any repair is
made on the power supply section, the following readjustment procedures are recommended:
1. Allow the monitor to warm-up for about 15 minutes.
2. Apply VGA (1024 x 768 @ 48.36 kHz/60 Hz) signal to the monitor.
3. Connect a DC voltage meter to D814 "-" (TP1 on the control PCB), and adjust VR801 for 13.3 + 0.2
V DC, 13.3 - 0 V DC.
4. If a fuse is broken during adjustment, remember to replace it with the exact same type of fuse.
Alignments and Adjustments 13
A1454 / A1554 NEL
4-2 Alignment Procedures
4-2-1 High Voltage Adjustment
CONDITION
Display image : Crosshatch pattern
PROCEDURE
Connect DC meter to TP3 and adjust VR802 to obtain a DC voltage of 152 ◦ Jabse Service Manual Search 2026 ◦ Jabse Pravopis ◦ onTap.bg ◦ Other service manual resources online : Fixya ◦ eServiceinfo