Compaq MV7500 User Manual

Compaq MV7500

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SERVICE MANUAL

LG: CA-110

LG CQ771G

MODEL: S7500 (PE1165T), S7500 (PE1165),

MV7500 (PE1165U), MV7500 (PE1165),
CV7500 (PE1165U)

CONTENTS

SPECIFICATIONS ................................................... 2

SAFETY PRECAUTIONS ........................................ 3

TIMING CHART ....................................................... 4

OPERATING INSTRUCTIONS ................................ 5

WIRING DIAGRAM ................................................. 6

BLOCK DIAGRAM ................................................... 7

DESCRIPTION OF BLOCK DIAGRAM.....................8

SPECIFICATIONS

1. PICTURE TUBE

Size : 17 inch
DefIection Angle : 90°
Neck Diameter : 29.1 mm
Dot Pitch : 0.28 mm
Face Treatment : Anti-Glare
Diagonal Inch : 16.06"

2. SIGNAL

2-1. Horizontal & Vertical Sync

1) Input Voltage Level: Low=0~1.2V, High=2.5~5.5V

2) Sync Polarity : Positive or Negative

2-2. Video Input Signal

1) Voltage Level : 0 ~ 0.7 Vp-p
a) Color 0, 0 : 0 Vp-p
b) Color 7, 0 : 0.467 Vp-p
c) Color 15, 0 : 0.7 Vp-p

2) Input Impedance : 75 Ω

3) Video Color : R, G, B Analog

4) Signal Format : Refer to the Timing Chart

2-3. Signal Connector

3 row 15-pin Connector (Attached)

ADJUSTMENT ...................................................... 10

TROUBLESHOOTING GUIDE .............................. 12

EXPLODED VIEW...................................................22

REPLACEMENT PARTS LIST ............................... 24

PIN CONFIGURATION........................................... 29

PACKING AND ACCESSORIES............................ 31

SCHEMATIC DIAGRAM......................................... 32

PRINTED CIRCUIT BOARD................................... 34

3-2. Power Consumption

MODE

FULL POWER

STAND-BY

SUSPEND

POWER OFF

4. DISPLAY AREA

4-1. Active Video Area :

• Max Image Size - 326.7 x 245.5 mm (12.86" x 9.67")

• Preset Image Size - 312 x 234 mm (12.28" x 9.21")
4-2. Display Color : Full Colors
4-3. Display Resolution : 1280 x 1024 / 60Hz

4-4. Video Bandwidth : 110 MHz

5. ENVIRONMENT

5-1. Operating Temperature: 10°C ~ 35°C (50°F ~ 95°F)

5-2. Relative Humidity : 8%~ 80%

5-3. Altitude : 5,000 m

POWER CONSUMPTION

less than 100 W

less than 5 W
less than 5 W
less than 5 W

(Non-Interlace)

(Ambient)

(Non-condensing)

LED COLOR

GREEN
AMBER
AMBER

OFF

2-4. Scanning Frequency

Horizontal : 30 ~ 70 kHz
Vertical : 50 ~ 140 Hz

3. POWER SUPPLY

3-1. Power Range

AC 100~240V , 50/60Hz, 2.0A

6. DIMENSIONS (with TILT/SWIVEL)

Width : 404.0 mm (15.90 inch)
Depth : 438.5 mm (17.26 inch)
Height : 426.0 mm (16.77 inch)

7. WEIGHT (with TILT/SWIVEL)

Net Weight : 15.1 kg (33.29 lbs.)
Gross Weight : 17.8 kg (39.24 lbs.)

SAFETY PRECAUTIONS

SAFETY-RELATED COMPONENT WARNING!

There are special components used in this color monitor
which are important for safety. These parts are marked

on the schematic diagram and the replacement

parts list. It is essential that these critical parts should be

replaced with the manufacturer's specified parts to
prevent X-radiation, shock, fire, or other hazards. Do not
modify the original design without obtaining written
permission from manufacturer or you will void the original
parts and labor guarantee.

CAUTION:

SAFETY CHECK

Care should be taken while servicing this color monitor
because of the high voltage used in the deflection circuits.
These voltages are exposed in such areas as the
associated flyback and yoke circuits.

FIRE & SHOCK HAZARD

An isolation transformer must be inserted between the

color monitor and AC power line before servicing the
chassis.

• In servicing, attention must be paid to the original lead
dress specially in the high voltage circuit. If a short
circuit is found, replace all parts which have been
overheated as a result of the short circuit.

• All the protective devices must be reinstalled per the
original design.

• Soldering must be inspected for the cold solder joints,
frayed leads, damaged insulation, solder splashes, or
the sharp points. Be sure to remove all foreign
materials.

No modification of any circuit should be
attempted.
Service work should be performed only after
you are thoroughly familiar with all of the
following safety checks and servicing
guidelines.

X-RADIATION

The only potential source of X-radiation is the picture tube.
However, when the high voltage circuitry is operating
properly there is no possibility of an X-radiation problem.
The basic precaution which must be exercised is keep the
high voltage at the factory recommended level; the normal
high voltage is about 25.5kV. The following steps describe
how to measure the high voltage and how to prevent X­radiation.

Note : It is important to use an accurate high voltage

meter calibrated periodically.

• To measure the high voltage, use a high impedance
high voltage meter, connect (–) to chassis and (+) to
the CDT anode cap.

• Set the brightness control to maximum point at full
white pattern.

• Measure the high voltage. The high voltage meter
should be indicated at the factory recommended level.

• If the meter indication exceeds the maximum level,
immediate service is required to prevent the possibility
of premature component failure.

• To prevent X-radiation possibility, it is essential to use
the specified picture tube.

CAUTION:

Please use only a plastic screwdriver to protect yourself
from shock hazard during service operation.

IMPLOSION PROTECTION

All used display tubes are equipped with an integral
implosion protection system, but care should be taken to
avoid damage and scratching during installation. Use only
same type display tubes.

TIMING CHART

VIDEO

SYNC

C

E

D

F

AB

<< Dot Clock (MHz), Horizontal Frequency (kHz), Vertical Frequency (Hz), Horizontal etc... (µs), Vertical etc... (ms) >>

Mode

1

2

3

4

5

6

7

8

9

Sync

H/V

Polarity

Sort

H – 37.500 26.667 20.317 6.349 2.032 3.810 0.508
V – 75.000 13.333 12.800 0.533 0.080 0.427 0.027
H – 31.469 31.778 25.422 6.356 3.813 1.907 0.636
V – 59.940 16.683 15.253 1.430 0.064 1.048 0.318
H – 43.269 23.112 17.778 5.334 1.556 2.222 1.556
V – 85.008 11.764 11.093 0.671 0.069 0.579 0.023
H – 31.470 31.778 25.422 6.356 3.813 1.907 0.636
V + 70.080 14.269 12.711 1.558 0.064 1.080 0.414
H + 46.880 21.330 16.160 5.170 1.620 3.230 0.320
V + 75.010 13.331 12.798 0.533 0.064 0.448 0.021
H + 53.674 18.631 14.222 4.409 1.138 2.702 0.569
V + 85.061 11.756 11.178 0.578 0.056 0.503 0.019
H + 60.023 16.660 13.003 3.657 1.219 2.235 0.203
V + 75.029 13.328 12.795 0.533 0.050 0.466 0.017
H + 68.677 14.561 10.836 3.725 1.061 2.201 0.508
V + 84.997 11.765 11.183 0.582 0.044 0.523 0.015
H + 63.98 15.63 11.85 3.78 1.04 2.30 0.44
V + 60.02 16.661 16.005 0.656 0.047 0.594 0.015

Frequency

Total Period

(E)

Video Active

Time (A)

Blanking Time

(B)

Sync Duration

(D)

Back Porch

(F)

Front Porch

(C)

Resolution

1024x768

1024x768

1280x1024

640x480

75Hz

640x480

60Hz

640x480

85Hz

720x400

70Hz

800x600

75Hz

800x600

85Hz

75Hz

85Hz

60Hz

OPERATING INSTRUCTIONS

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FRONT VIEW REAR VIEW

See Front Control Panel

Power ON/OFF Button

Front Control Panel

1. Power/LED

Controls power to the monitor.
The LED on the power button is illuminated when the
power is on.

2. Right Adjustment

Moves clockwise through menu options or increases
adjustment levels.

AC Power Socket

Signal Connector

4. Select

Launches on-screen displays, selects functions and
adjustments, and exits menus and On-Screen Display.

5. Hot Key

Left Adjustment
Just select left adjustment key without OSD display.
Contrast menu display.

3. Left Adjustment

M

oves counter-clockwise through menu options or

decreases adjustment levels.

Right adjuatment
Just select right adjustment key with OSD display.
Brightness menu display.

P501

P201

P405

P301

P302

P303

P702

P701

T1

P402

P902

S

+

S

Signal

Cable

AC

Socket

FBT

MENU

POWER

POWER INPUT

100~240VAC

(50/60Hz)

Line
Filter

Degaussing
Circuit

< OSD Control >

SMPS

TRANS

(T901)

SMPS
CONTROL
(IC901)

DPM

CONTROL

CIRCUIT

Voltage

Regulating

Circuit

80V
50V

15V

6.3V

TILT
Control
Circuit

6.3V

15V

E2PROM
(IC402)

H POSITION

BRIGHTNESS

CONTRAST

H SIZE
V POSITION
V SIZE
SPCC
TRAPEZOID
PIN BALANCE
PARALLELOGRAM
ROTATION
DEGAUSS
COLOR TEMPERADURE
FACTORY RECALL

EXIT

5V

OSD IC

(IC301)
NT6872

H-Sync Sig
V-Sync Sig

I2C DATA(SDA)
I2C CLOCK(SCL)

VIDEO

LM1269

PRE-AMP
(IC302)

Signal
Cable

R

G

B

VIDEO

LM2467

LM2480

CUT OFF IC
(IC304)

MAIN AMP
(IC303)

5V

5V

H/V Sync Processor

( IC701 )

TDA4857

V-OUT

( IC601)

TDA4866

H-OUT

( Q706)

H-Linearity

Correction

DC/DC Converter

X-RAY

Protection

Circuit

FBT

( T701 )

Dynamic

Focus
Circuit

Auto
Beam
Limit

Vertical Blanking,

Brightness Control

- 160V

40V

400V

STEP UP

15V

D/D Feed Back

15V

MICOM
(IC401)

SCL / SDA

H/V Sync,

PWM Control

15V

5V

15V

80V

15V

50V

DY CDT

Heater ( 6.3V )

I

2

C

I

2

C

I2C

H/V

Sync

G
1

Screen(G2)

Dynamic Focus

Static Focus

H.V

R/G/B

Drive/Contrast

Cut-Off

H-DRV

B-DRV

B+

15V

TILT

COIL

DEGAUSSING

COIL

I2C

Vout 1
Vout 2

+

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DESCRIPTION OF BLOCK DIAGRAM

1. Line Filter & Associated Circuit.

This is used for suppressing noise of power input line
flowing into the monitor and/or some noise generated in
this monitor flowing out through the power input line.
That is to say, this circuit prevents interference between
the monitor and other electric appliances.

2. Degauss Circuit & Coil.

The degauss circuit consists of the degaussing coil, the
PTC(Positive Temperature Coefficient) thermistor(TH901),
and the relay(RL901). This circuit eliminates abnormal
color of the screen automatically by degaussing the
shadow mask in the CRT during turning on the power
switch. When you need to degauss in using the monitor,
select DEGAUSS on the OSD menu.

3. SMPS(Switching Mode Power Supply).

This circuit is working of 90~264V AC(50/60Hz).
The operation procedure is as follows:

1) AC input voltage is rectified and smoothed by the bridge
diodes (D900) and the capacitor (C908).

2) The rectified voltage(DC) is applied to the primary coil
of the transformer(T901).

3) The control IC(IC901) generates switching pulse to turn
on and off the primary coil of the transformer (T901)
repeatedly.

4) Depending on turn ratio of the transformer, the
secondary voltages appear at the secondary coils of the
transformer(T901).

5) These secondary voltages are rectified by each
diode(D941, D942, D951, D961, D962, D971) and operate
other circuit. (horizontal and vertical deflection, video
amplifier, ...etc.)

4. Display Power Management Circuit.

This circuit control power consumption of the monitor by
detecting H and V sync signal. There are off mode. When no
horizontal or vertical sync signal input, the circuit consists of
Q941 and Q951 becomes off mode. It’s power consumption
is below 5W.

5. X-ray Protection.

If the high voltage of the FBT reaches up to 29kV (abnormal
state), IC401(MICOM) pin 35 Sensing from FBT directly.
Then MICOM control IC701 (Deflection controller) to stop
Horizontal drive pulse and stop Horizontal Deflection.

6. Micom(Microprocessor) Circuit.

The operating procedure of Micom(Microprocessor) and
its associated circuit is as follows:

1) H and V sync signal is supplied from the signal cable.

2) The Micom(IC401) distinguishes polarity and
frequency of H and V sync.

3) The Micom sets operating mode and offers the
controlled data. (H-size, H-position, V-size, ... etc.)

4) The controlled data of each mode is stored in itself.

5) User can adjust screen condition by each OSD
function. The data of the adjusted condition is stored
in EEPROM(IC402).

7. Horizontal and Vertical Synchronous Processor.

This circuit generates the horizontal drive pulse and the
vertical drive pulse by taking sync-signal from the Signal­Cable. This circuit consists of the TDA4857(IC701) and
the associated circuit.

8. D/D(DC to DC) Converter.

This circuit supplies DC voltage to the horizontal deflection
output circuit by increasing DC 50V which is the
secondary voltage of the SMPS in accordance with the
input horizontal sync signal.

9. Side-Pincushion & Trapezoid Correction Cirucit.

This circuit improves the side-pincushion and the
trapezoid distortion of the screen by mixing parabola and
saw-tooth wave to output of the horizontal deflection D/D
converter which is used for the supply voltage(B + ) of the
deflection circuit.

10. Horizontal Deflection Output Circuit.

This circuit makes the horizontal deflection by supplying
the saw-tooth current to the horizontal deflection yoke.

11. High Voltage Output & FBT(Flyback Transformer).

The high voltage output circuit is used for generating pulse
wave to the primary coil of the FBT(Flyback Transformer) .
A boosted voltage(about 25.5KV) appears at the
secondary of the FBT and it is supplied to the anode of the
CDT. And there are another output voltages such as the
dynamic focus and the screen voltage(G2).

12. H-Linearity Correction Circuit.

This circuit corrects the horizontal linearity for each
horizontal sync frequency.

13. Vertical Output Circuit.

This circuit takes the vertical ramp wave from the
TDA4857(IC701) and performs the vertical deflection by
supplying the saw-tooth current from the TDA4866(IC601)
to the vertical deflection yoke.

14. Dynamic Focus Output Circuit.

This circuit takes the horizontal and the vertical parabola
waves from the TDA4857(IC701) and amplifies it to
maintain constant focus on center and corners in the
screen.

15. H& V Blanking and Brightness Control.

Blanking circuit eliminates retrace line by supplying
negative pulse to the G1 of the CRT. And Brightness
circuit is used for control of the screen brightness.

18. Video Pre-Amp Circuit.

This circuit amplifies the analog video signal from 0-0.7V
to 0-4V. It is operated by taking the clamp, R, G, B drive
and contrast signal from the Micom(IC401).

16. Image Rotation (Tilt) Circuit.

This circuit corrects the tilt of the screen by supplying the
image rotation signal to the tilt coil which is attached near
the deflection yoke of the CRT.

17. OSD Circuit

This circuit is used for performing the OSD(On-Screen­Display) function.
When a user selects the OSD Select/Adjustment control,
the adjustment status displays on the screen.

19. Video Output Amp Circuit.

This circuit amplifies the video signal which comes from
the video pre-amp circuit and amplified it to applied the
CRT cathode.

GENERAL INFORMATION

ADJUSTMENT

All adjustment are thoroughly checked and corrected
when the monitor leaves the factory, but sometimes
several adjustments may be required.
Adjustment should be following procedure and after
warming up for a minimum of 30 minutes.

• Alignment appliances and tools.

- IBM compatible PC.

- Programmable Signal Generator.
(eg. VG-819 made by Astrodesign Co.)

- EPROM or EEPROM with saved each mode data.

- Alignment Adaptor and Software.

- Digital Voltmeter.

- White Balance Meter.

- Luminance Meter.

- High-voltage Meter.

AUTOMATIC AND MANUAL DEGAUSSING

The degaussing coil is mounted around the CDT so that
automatic degaussing when turn on the monitor. But a
monitor is moved or faced in a different direction, become
poor color purity cause of CDT magnetized, then

DEGAUSS on the OSD menu.

press

ADJUSTMENT PROCEDURE & METHOD

-Install the cable for adjustment such as Figure 1and run

the alignment program on the DOS for IBM compatible PC.

-Set external Brightness and Contrast volume to max position.

1. Adjustment for B+ Voltage.

1) Display cross hatch pattern at Mode 8.

2) Check C999 (+) voltage to 50± 0.5Vdc.

2. Adjustment for High-Voltage.

1) Display cross hatch pattern at Mode 8.

2) DIST.ADJ→CTRL PWM → High Voltage Command.

3) Adjust High Voltage to 25.5kV

4) Press Enter Key.

3. Adjustment for Factory Mode (Preset Mode).

1) Display cross hatch pattern at Mode 1.

2) Run alignment program for CQ771G on the IBM
compatible PC.

3) EEPROM → ALL CLEAR → Y(Yes) command.

<Caution> Do not run this procedure unless the
EEPROM is changed. All data in EEPROM (mode
data and color data) will be erased.

4) Power button of the monitor turn off → turn on.

5) COMMAND→PRESET START→Y(Yes) command.

6) DIST. ADJ. → CTRL PWM → TILT command.

±

0.3 kVdc.

7) Adjust tilt as arrow keys to be the best condition.

8) DIST. ADJ. → BALANCE command.

9) Adjust parallelogram as arrow keys to be the best
condition.

10)

Adjust balance of pin-balance as arrow keys to be

the best condition.

11)

DIST. ADJ. → FOS. ADJ command.

12)

Adjust V-SIZE as arrow keys to 234±2mm.

13)

Adjust V-POSITION as arrow keys to center of the
screen.

14)

Adjust H-SIZE as arrow keys to 312±2mm.

15)

Adjust H-POSITION as arrow keys to center of the
screen.

16)

Adjust S-PCC (Side-Pincushion) as arrow keys to be
the best condition.

17)

Adjust TRAPEZOID as arrow keys to be the best
condition.

18)

Save of the Mode 1.

19)

Display from Mode 1 to 8 and repeat above from
number 12) to 19)

20)

PRESET EXIT → Y (Yes) command.

4. Adjustment for White Balance and Luminance.

1) Set the White Balance Meter.

2) Press the DEGAUSS on the OSD menu for
demagnetization of the CDT.

3) COLOR ADJ. → LUMINANCE command of the
alignment program.

4) Set Brightness and Contrast to Max position.

5) Display color 0,0 pattern at Mode 8.

6) COLOR ADJ.→ BIAS ADJ.→ COLOR No. → 1
command of the alignment program.

7) Check whether green color or not at R-BIAS and G­BIAS to min position and B-BIAS to 127(7F) and
Sub-Brightness to 177(B1) position. Adjust G2
(screen) command to 0.4
luminance.

8) Adjust R-BIAS and G-BIAS command to x=0.283

0.005 and y=0.298
Meter with PC arrow keys.

9)

Adjust SUB-Brightnesscommand to 0.5±0.1FL of the
raster luminance.

10)

Adjust repeat number 8).

11)

After push the “ENTER” key.
COMMAND → PRESET START → Y(Yes) command.

11-1)

12)

Display color 15,0 full white pattern at Mode 8.

13)

DRIVE ADJ.→ No 1. command.

±

±

0.05FL of the raster

0.005 on the White Balance

±