BELINEA 103026 User manual

_ Belnea
Service Manual
17-inch Color Monitor
(Belinea 103026)

Belnea (Maxdata 103026)
Table of Contents
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Belnea
1
Precautions
(Maxdata 103026)
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
j-
1.
1-1 Warnings
For safety purpose, do not attempt to modify
the circuit board, and always disconnect the AC
power before performing servicing on the
monitor.
. 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.
. 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.
. 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.
. 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
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.
. Inspect all protective devices such as
nonmetallic control knobs, insulating materials,
cabinet backs, adjustment and compartment
covers or shields, isolation resistor-capacitor
networks, mechanical insulators, etc.
. 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 anda
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
To exposed meatal
cabinet part
To known
earth ground
4500 ohm 10 watt
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.
Page 2
Precautions

Belnea (Maxdata 103026)
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
ot
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 Page} |

Belnea (Maxdata 103026)
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) Ifthe 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 Precautions

Belnea (Maxdata 103026)
2 Product Specifications
2-1 Specifications
17-inch (16-inch Visual image area), sloted mask, 90 degrees
Picture Tube deflection, dot type black matrix, medium short persistence
phosphor, dark tint, non-glare/ anti-static screen,
0.28 mm dot pitch
s ing F Z VGA, Super VGA, 1024x768@60/70/75/85 Hz
eRRRE ee REGUS? 1280x1024@60Hz
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
Colors
Analog
|
ty,
jimited
Colors
Input
Horizontal: 30 to 70 kHz
Frequencies Vertical : 50 to 160 Hz
iso Sk _[Amfon'07 ven ROB peeve =
75 Watts (maximum) AC rated voltage, 100VAC to 240VAC
Center Area : < 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, Display Frequency,
Degauss, Recall, H. Moire,
V. Moire
Service Controls PWB-1618
PWB-1606 : power voltage adjust (VR801), high voltage adjust
10 (see Table 2-2. Timing Chart)
Operation temperature : 10°C to 40°C ambient
Operation Humidity : 20% to 80% ambient
Storage temperature : -40°C to 65°C ambient
Storage Humidity : 10% to 90% (non-condensing)
Altitude : Non operating 40,000 feet sea level
operating 10,000 feet sea level
User Controls
Environmental
Considerations
Note: Above specifications are subject to change without prior notice.
Product Specifications Pages |

| Belnea (Maxdata 103026)
2-2 Signal Cable Pin Connections
Table 2-1. Signal Cable Pin Assignment
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Note* This pinis used for selftest detection. Connect this pin to ground at the PC end.
** — For PC 99: This pin will provide +5V from PC side.
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| Page 6 Product Specifications

Belnea (Maxdata 103026)
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
Pa Ee ce aee ee ees eee
H. Dots 720 640 640 640 800 800 1024 800 1280 1024
V. Dots 400 480 480 480 600 600 {| 600 1024 768 |
37.5
H-freq (kHz)
Syne Polarity
A period us
B Blking us
C Syne us
D B.P. us
E Active us
F FE.P. us
V-freg (Hz)
Sync Polarity
O Period ms
P Biking ms
Q Sync ms
R B.P. us
S Active us
T F.P. us
Seperate Sync
Horizontal E Vertical .
Video == Video iw
o
J
4
Le
a
H.Parameters: V.Parameters:
A: Period B: Blanking Time G: Period H: Blanking Time
[ C: Syne Width D: Back Porch L Sync Width J: Back Porch
ae E: Active Time F: Front Porch K: Active Time L: Front Porch
Product Specifications Page? }

Belnea (Maxdata 103026)
2-4 Display Power Management Signal (DPMS)
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. Display Power Management Signal (DPMS)
State Power LED
Cousumption Light
Active
<
* For power consumption : 75W Max. (@ 230V AC, preset size and maximum light output condition)
2-5 TCO Version (Optional)
The monitor meets the TCO 95/99, NUTEK energy saving, electric and magnetic field requirements.
Also it is compliant with TCO 95/TCO 99 labelling scheme.
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 sum-
marized in the Table 2-4.
Table 2-4. TCO 95 Emission Requirements
Electrostatic +/- 500 V +/- 500 V
Potential
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 Product Specifications

Belnea 3 (Maxdata 103026)
2-5-1 TCO 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 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
Linearity 1% or less Difference in length of columns or rows compared to the
corresponding lengths through the center of the monitor.
Luminance 1.7:1 or less The ratio is between the max to min luminance within the
Uniformity whole active area.
2-5-2 TCO 99 Version (Optional)
TCO 99 will append the color temperature and energy efficiency specification, also cover the environment]
requirement.
Product Specifications . Page 9 |

Belhea (Maxdata 103026)
3
Control
Location
and
Functions
(1)
(2)
(3)
(4)
(5)
(1) Power LED
(2) ENTER Key
(3) Flywheel Knob
(4) MENU/EXIT Key
(5) Power Button
3-1 Front Panel
3-2 Front Panel Keys Functions
1.
Power
LED:
Display
different
modes
(ON
or
OFF)
of
the
monitor
by
showing
different
color
for
each
mode.
2. ENTER Key: To activate the function.
3. Flywheel Knob: To select the desired function icon using the OSD dial.
4. MENU/EXIT Key: To display the OSD menu on or exit the screen,
5. Power ON/OFF: To turn the monitor ON and OFF.
3-3 Adjustment Procedure
1. Press (5) key to turn on the monitor.
2.
At
normal
condition,
press
(4)
key
on
the
front
panel
to
activate
the
on-screen
manager
(OSM)
menu.
3,
Rotate
the
flywheel
to
highlight
an
option.
The
name
of
the
highlighted
option
appears
in
the
center
of
the
menu.
4. Press (2) key to select the highlighted option, then rotate the flywheel to adjust it.
Some
options
can
only
be
enabled
or
disabled,
like
Manual
Degauss,
Memory
Recall.
There
are
also
some
options that
contain
additional
menus.
5. Press (2) key again.
6. Repeat steps 3 to 5 until you have made all your changes,
7, Press (4) key to exit the OSD control system.
Note: To enter the “Internal Adjustment” mode, press (2) key and hold it then press (5) key.
| Page 10 Operation Theory

Belnea (Maxdata 103026)
4 Operation Theory
This
is
a
fully
digital
controlled
multi-sync
color
monitor
that
is
compliant
with
DDC1
and
2B
Plug
and
Play
VESA
standard
and
offers
the
following
main
features.
4-] Main Features
1. Simplified design with minimum components.
2.
The
MYSON
MTV212
M(A)
32
processor--
that
has
IC
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)
’C
Bus
for
auto-alignment
through
signal
cable
(g)
CS1/CS2/CS3/CS4
for
linearity
and
size
compensation.
3.
Stores
up
to
10
factory
preset
modes
and
offers
8
user
modes.
There
are
16
function
icons
at
OSD.
They
are
controlled
by
{]
«
»
[z]
keys
on
front
panel.
4.
Powerful
PHILIPS
TDA4863
and
TDA4841
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)
Comer
correction
--
factory
adjust,
(h)
Pincushion
unbalance
correction
--
factory
adjust,
(i)
Parallelogram
distortion
--
factory
adjust,
(j)
Moire
cancellation,
(k)
X-ray
protection,
and
(1)
Full
horizontal
and
vertical
auto
sync
capability.
5.
Software
controlled
auto
shut
off
function
activated
if
fH
<=
29
kHz
and
fH
>
=
70
kHz.
6. Full range AC input and simplified line filter design.
4-2 Microcontrol Section
1.
This
monitor
uses
MYSON
MTV212
M(A)
32
CPU.
It
contains
a
8051
8-bit
CPU
core,
256
bytes
of
RAM
used
as
working
RAM
and
stack
area,
32k
bytes
of
OTP
ROM,
13-channel
8
bit
PWM
D/A
converter,
2-channel
A/D
converters
for
key
detection
saving
I/O
pins,
internal
H.
sync
and
V.
syne
signals
processor
providing
mode
detection,
and
an
’C
bus
interface.
When
H/V
sync
through
D-Sub
signal
cable
enter
pin
41
and
pin
42,
the
CPU
performs
frequency
/
polarity
detection
and
calculate
and
send
to
H/V
sync
OUT.
Then
CPU
reads
the
data
from
1703
and
transfer
to
device
4841
and
some
DAC
in
CPU,
above
operation
takes
about
500
ms.
2.
There
allowed
8
factory
preset
modes
and
8
user
modes.
There
are
11
functions,
Contrast,
Brightness,H.
Size,
H.
Position,
V.
Size,
V.
Position,
Pincushion,
and
Trapezoid,
Rotation,
H.
Moire,
V
Moire,
all
controled
by
OSD
icon
which
can
be
adjusted
by
user.
3.
The
pin
27
and
pin
28
are
used
for
ATE
function.
When
CPU
receives
C6
as
slave
address,
it
will
ope
te
in
ATE
mode
which
is
used
for
auto-alignment.
After
alignment
the
data
will
be
stored
in
1703,
4.
The
user
control
parameters
are
selected
by
OSD
icons,
through
[1]
«
&
p
a]
keys,
they
are
detectedby
sensing
the
voltage
through
R710,
R740,
R741,
R743,
R716,
R717
to
pin
25
and
26
of
1701.
4-3 Deflection Section
1. PC -- autosync deflection controller is TDA4841.
2.
The
TDA4841
is
a
high
performance
and
efficient
solution
for
autosyne
monitors.
All
functionsire
controllable
by
?C
bus.
SDA
and
SCL
signals
coming
from
microprocessor
feed
to
pin
19
and
pin
li
to
control
all
functions.
Operation Theory | Page 1 |

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Belnea (Maxdata 103026)
4-3-1 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 goes into pin 15 through R318. And horizontal flyback pulse goes into pin | through R401
and bypass filter C403 from pin 6 of FBT and R496 for HFLB loop.
3. Horizontal driver (pin8) O/P to Q401 via C410.
4-3-2 Vertical Section
1. Vertical sync goes into pin 14 through R317.
2. The free running frequency is determined by R301 and C301.
4-3-3 Vertical O/P section
1. The differential output currents from pin 13 of Vout! and pin 12 of Vout2 can be directly coupled to the
vertical deflection booster pin 1 and pin 2 of TDA4863J.
2. The TDA4863 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. This IC is powered by two sets of positive voltage and one set of negative voltage. (+12V at pin 1, -12V
at pin 4, +35V at pin 2).
4-3-4 E-W/Trapezoid and H. Width Controls
1. The horizontal O/P stage uses diode modulator D419, D433, 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 TDA4841.
The H. width / corner and trapezoid correction are also accomplished by this pin 11. The DC level
controls H. size. The AC level is combined with side pin and trapezoid corners functions.
4-3-5 X-Ray Protection
1. To avoid X-ray hazard, a DC voltage generated at pin 6 of FBT and rectified by D408, C432 and divided
by R403, R404 and R405 come into pin 2 of TDA4841.
2. If this voltage is higher than 6.39 V, then TDA4841 will be activated to float HUNLOCK (pini7), H.
DRV( pin 8), B DRV (pin 6), VOUT! (pin 12), VOUT2 (pin13). After that all deflection circuit stop
working.
4-3-6 G1, Blanking and Brightness
1. The vertical blanking signal comes from two ways. One is from pin 8 of I301 (TDA4863), the other is
from vertical sync (pin 32 of 1701). These two positive vertical pulses through Q405 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 cutoff Q407, then G1
will go down to -150V. During the mode change, Mute acts as same as HUNLock’s.
4-3-7 Contrast Section
1, Contrast is controlled by 1701 through PC bus to 501 (LM1267) directly.
2. Beam current is detected through T402 (FBT) pin 7, C429, R449 and detected voltage feeding into Q432,
| Page 12 Operation Theory

Belnea (Maxdata 103026)
Q433, R436, R497, R459, C482 to control 1501 pin 22 voltage. When [501 pin 22 voltage drops
below 4.1 V, the ABL function will happen.
4-3-8 H/V size breathing compensation
1. Beam current is sensed as above section (3-3-7 item 2) and this voltage routes through R451, R468, C470
then through R437 to 1401 pin 31 for H. size compensation.
2. HV voltage is detected through T402(FBT) pin 11. C481, R4F4, R4F8, R4F9, Q428, R4GO, Q431, RAGI,
then through R302 to 1401 pin 21 for V. size compensation.
4-3-9 Dynamic focus circuitry
The dynamic focus is applied to improve the corner focus performance, it includes horizontal and vertical
dynamic focus.
1. Horizontal dynamic comes from C413 through R435, C450, T401, R434, C448 and feed to FBT dynamic
focus pin (T401 pin 12).
2. Vertical dynamic comes from 1401 pin 32 through C315, R322, R326, R321, R323, Q301, R324, R325 and
feed to FBT dynamic focus pin.
4-4 Power Supply Section
4-4-1 AC Rectifier
The circuit can accept 90 V to 264 V AC input through D801~D803 bridge diodes and C808 filtering to get
DC 126 V~364 V for power conversion in T802.
4-4-2 Line Filter
It consists of C803, T801, C804, C805, C808, C819, C807, C817 and meets EMI regulation.
4-4-3 Power LED Status
1. The LED has 3 leads with common cathode to emit green and amber color light for different power
saving states. It is controlled by CPU.
2. Normal: Green light
Amber LED is off because CPU pin 30 is 1.96V and pin 31 is 0.45V, only green LED is turned on.
3. Off Mode : Amber light
CPU pin 30 is 1.87V and pin 31 is 0.46V, then green is off and amber is illuminated.
4-4-4 Auto Degaussing
When S801 turns on, pin 14 of I701 will send a signal to Q802 and turns on RL801 for degaussing. Afr 4
seconds, it will turn off RL801 automatically.
4-4-5 PWM Control
i. Start Up
The [801 (5S0765C) gets power from R807, R808, C830 and pin 3 voltage reaches 15 V for starting p.
Operation Theory Page 3 |

Belnea | (Maxdata 103026)
The I801 starts oscillation at 20 kHz, pin 1 output to drive T802. Switching on, R819 set up an 15 V to
keep 1801 working through D809 auxiliary voltage.
2. Regulation
The DC O/P voltage is proportional to the auxiliary voltage, so 1801 pin 4 senses the feedback voltage
from the divider D806, R809, C810, VR801, Q803, Q801 and R821 to compare with the built-in 1.5 volts
reference voltage for error amplifier operation. Finally pin 6 can modulate the different duty cycle by
VR801 setting to achieve regulation purpose.
4-4-6 Synchronization
1. Normal Mode
The sync pulse from FBT (31 kHz~69 kHz) via R812, R811 and C815 to pin 5 of [801 to keep 1801
synchronized with horizontal sync input frequency.
2. Power Saving Modes: Standby/Suspend
Because there is no pulse from FBT, so the free-run frequency SMPS works at 20 kHz by [801 itself.
3. Override
The horizontal free run frequency is about 63.2 kHz under override condition, SMPS is synchronized to
this frequency.
4-4-7 O.V.P.
If the auxiliary voltage is higher than 25 volts makes pin 3 of 1801 is limited to have the OVP activated.
4-4-8 O.P.P.
The excess current of T802 through [801 pin 1, 2, make Vs>1.1V internal of 1801, then limite the power.
4-4-9 Step Up Power Supply For FBT
1. The B+ of FBT is proportional to horizontal frequency, that is the higher frequency, the higher voltage.
The basic voltage is 58 volts from T802 pin 10 via L811, D813, C824 and the gate control of Q451 comes
from 1401 pin 6 via Q450, Q434, D435 and R4E5. The duty cycle is controlled by 1701 pin 33 (PWM pin
Adj.) via R719, C741, R4F6, R4F5, R4F1.
2. The regulation and boost up (from 68 V to 160 V or more, on demand). The H.V. is set at 25.6 kV (zero
beam) by 1301 pin 33 which senses the secondary O/P from FBT. The booster comprises Q451, L410,
L411, D450, C425 and T802 to offer the required B+ for different frequency modes.
4-5 Video Amplifier Section
1. RGB signal inputs are terminated by R501, R531 and R561 then pass through the coupling capacitors
C503, C533 and C563 to IC501 LM1267 prearnplifier.
2. The amplifier RGB signals (0~3 Vpp) are adjusted by ?'C bus, [501 pin 23 is for clamp pulse which comes
from pin 16 of TDA4841 to set up equal clamp level.
3. The video output stages are amplified by 1502 (LM2469).
4. The RGB cathodes cut off are adjusted by 1503 (LM2479) pin 8, 7, 6, which comes from IS01 pin 16, 15,
14 to adjust cut iff voltage level by PC bus.
5. Under override condition, “NO SIGNAL” will show up on the screen.
| Page 14 Operation Theory

Belnea (Maxdata 103026)
4-6 OSD (On Screen Display) Circuit
1. The 1504 MTV021-08 is OSD IC. The OSD signals are worked by positive vertical pulse from 1701 pin
34 that goes through R720 to 1502 pin 10, and positive horizontal pulse from T402 pin 5 goes through R496
to 1502 pin 5. CPU I701 pin 13, 12 (?C bus) transfers information to I502 pin 7, 8.
2. The OSD R. G. B signals and blanking signal are terminated at 1502 pin 15, 14, 13, and 12 to [501 pin 1,
2, 3 and 4 then the OSD picture appears.
Operation Theory Page 15 |

Belnea - (Maxdata 103026)
5 Alignments and Adjustments
This
section
of
the
service
manual
explains
how
to
make
permanent
adjustments
to
the
monitor
settings.
5-1 General Adjustments
5-1-1 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
=
68.68
kHz,
FV
=
85
Hz,
unless
otherwise
defined.
5-1-2 EquipmentRequired
The following equipments are necessary for adjustment procedures:
1. Volt-ohm-A meter (Sanwa FD-750C or equivalent)
. 30 kV high voltage probe (HP34111A)
. Oscilloscope (TEK2235 or equivalent)
. Minolta Color Analyzer 0
. Signal generator (IBM PC with proper display cards or Chroma 2000)
nan th WY WY
. Screwdriver
5-1-3 Switching Power Supply and Regulator Adjustment
a.
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 @ 68.68 kHz/85 Hz) signal to the monitor.
3.
Connect
a
DC
voltage
meter
to
TP001
(on
the
Main
board),
and
adjust
VR801
for
11.7
+
0.1
Vdc
4. Ifa fuse is broken during adjustment, remember to replace it with the exact same type of fuse.
b. Ifnecessary, follow the following procedures to enter the factory mode.
1. Press ENTER key simultaneously then power ON.
2. After turn the power off, this monitor will go back to normal mode.
| Page 16 Alignments and Adjustments

Belnea _ (Maxdata 103026)
5-2 Alignment Procedures
5-2-1 High Voltage Adjustment
CONDITION
Press
ENTER
key
simultaneously
when
switching
the
power
“On”.
Display
image
:
No
video
(68.68kHz
Mode)
PROCEDURE
Connect DC meter to TP002 and adjust HV (i)
R802
to
obtain
a
DC
voltage
of
-152.2
+
0.2
V
DC
(Sampo
FBT)
or
-153
+
0.2V
DC
(LCE
FBT)
for
CPT
CRT
M41AJR53X46
(TCO)
.
5-2-2 Screen and White Balance Adjustment
CONDITION
Press ENTER key simultaneously when switching the power “On”,
Display image : No video (68.68kKHZ Mode)
PROCEDURE
1 Raster color setting
l-a. Set Brightness max. to 77 (OSD cursor) and 500 + 5 at G2.
1-b Adjust R and B cutoff to min.
1-c Adjust G cutoff to about 0.45FL
l-d
Adjust
B
cutoff
to
get
y=298
+
5,
R
cutoff
to
get
x=283
+
5
and
Y=0.65
+
0.05
FL.
1-e
Adjust
Brightness
cutoff
to
raster
0.01-0.02
FL.
CONDITION
Display image : 50 mm x 50 mm white block pattern
PROCEDURE
2 6500°K. color temperature setting
2-a. Set Brightness to cutoff and Contrast to maximum.
2-b
Move
cursor
on
OSD
to
choose
color
temperature
icon.
2-c.
With
green
block
pattern,
adjust
G
gain
to
get
Y
about
32FL.
2-d
Adjust
R.B.
gain
to
get
x=313
+5,
y=329
+
5;
and
Y=43
+
0.5FL
©
3 9300°K color temperature setting
3-a. Set Brightness to cutoff and Contrast to maximum.
3-b Move cursor on OSD to choose color temperature icon.
3-c. With green block pattern, adjust G gain to get Y about 32FL.
3-d Adjust R.B. gain to get x=298+5, y=297+5; and Y=4340.5FL
Alignments
and
Adjustments
Page
[7
|

Belnea (Maxdata 103026)
4 Full white ABL setting
CONDITION
Display image : full white pattern
4-a Set Brightness to cutoff and Contrast to maximum.
4-b, Adjust ABL to Y=32FL + 0.5FL.
4-c, Check the white balance at SFL and 28FL.
4-d. Repeat all the procedures in 4-2-2 section until the best white balance is obtained.
5-2-3 Focus Adjustment
CONDITION
Display image : “me” character pattern (68.68 kHz Mode)
PROCEDURE
1. Set Brightness to cutoff and Contrast to maximum,
2. Adjust focus 1 at T402 (static focus VR) to make vertical line clear.
3. Adjust focus 2 at T402 (static focus VR) to make horizontal line clear.
4. Repeat above procedures to get best focus.
5-2-4 Static Convergence Adjustments
Static convergence involves alignment of the red, blue and green lines in the center area of the display.
Note: The monitor requires 30 minutes of warm-up time for convergence adjustment.
CONDITION
Display image : Crosshatch pattern
Warm-up Time : 30 minutes
PROCEDURE
1. Set Brightness and Contrast to display a well-defined pattern.
2. Ensure the convergence magnet rings are correctly positioned on the CRT.
Figure 4-1. Convergence Magnets on the CRT
937654 3 2
1) Setup Bolt 2) Bow Magnet 3) Band 4) 2-Pole Magnet
5) Spacer 6) 4-Pole Magnet 7) Spacer 8) 6-Pole Magnet
9) Holder 10) Band 11) Tabs
| Page 18 Alignments and Adjustments