saleem Monitor 9

7/28/2019 saleem Monitor 9

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MONITOR

IDENTIFICATION COMPONENTS IN MONITOR:

1.CRTor PT .(cathode ray tube or picture tube).

2.YOKE( horizontal deflection coil,VDC-vertical deflection coil)3.Degaussing coil4.Shield wire5.Ring magnets6.CRT Base or PT base.

1. video amplifier.2. video driver.3. video output

7.Power connector.8.Line filter.9.Bridge rectifier.

10.SM Transformer.11.Diodes12.Capacitors13.Resistors15.IC's.

1.Micro processor I.C2.Memory I.C3.Vertical I.C

16.Driver transformer17.Relay18.Coils

19.LOT(extra high tension,focus,screen)20.Heat sync21.Presets22.Crystal23.Fuse24.PTC(positive thermal conductor)25.Micro switch26.LED27.Iron core

DATA CABLETypes of monitors:1.CGA,XGA,EGA- All are 9 pins connector(9 pin data cable).These monitors cannotsupport graphics.2.VGA,SVGA,AGP- all are 15 pin connectors (15 pin data cable).These monitorssupport graphics.

CGA- color graphic adapter.XGA- extended graphic adaptor.VGA- video graphic adaptorSVGA- super video graphic adaptor.
mailto:[email protected]:[email protected]


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pin no Description

1. Red input2 green input3 blue input4 dummy5 ground or circuit or sensing6 red return ground7 green return ground8 blue return ground9 dummy10 ground11 dummy

12 sensing or circuit or dummy13 Horizontal( H-sync) input14 Vertical(V-sync) input15 Sensing or circuit or Dummy.

Primary colors----- Red,Green.Blue.Secondary colors--- Magenta(G+B), Yellow(B+R),Cyan(R+G).

Color picture tubes are two types:1.Broad neck 2.Narrow Neck.Pin no Description1 Focusing Grid G3234 dummy5 Control grid G16 Green cathode7 screen grid G2


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8 Red cathode9,10 Filament11 blue cathode12,13,14 dummy

Narrow neck:

Pin no Description:

1 Focusing Grid G32 Dummy3 Blue catode4,5 Filament6 Control grid G17 Red cathode8 Sreen Grid G2

9 Green cathode10 Dummy

Function of picture Tube:1* Front side of picture tube is called as screen.2* Back side of picture tube is called as neck.3* Centre part of screen neck called as funnel.4* Phosphorus coating applied inside of the screenAlluminium coating applied for safety purpose on the screen,

when electrons comes on screen it can reflects backsideto stop back reflection aquadag coating applied inside of funnel.

5* Aquadag coating also applied outside of the funnel andit connected to nagative voltage.6* Electron Gun located at part of neck.7* Inside of the neck we can found filament cathode(controlgrid,screen grid and focussing grid).8* Through the electron gun electron beam passes to screen.9* When the electrons fall on backside of screen havingphosphorous coating small spark light appears.

1.Filament:when we apply voltage to filament it will be heat and give heat to cathode

and cathode will be heat.we can also called heater.It is denoted by H or F.2.Cathode:

when we apply voltage to filament it will be heat and give heat to cathode,after cathode become heat,the electrons come outside because of the nikhil oxidecoating applied to cathode.It is denoted by K.3.Control Grid:

It controls flow of electrons passes from cathode to screen.It increases anddecreases of flow of electrons. when we are apply voltage vary the brightness


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controlling.If electrons are passing or generate low brightness decreasing.If electrons

are generate high brightness increasing.4.Screen Grid:

The electrons cannot move from control grid to screen due to long distance

between control grid to screen.For pass the electrons from control grid to screenwe need some force,for forcable purpose we are using one grid.The grid will workwith +ve voltage only.with the help of +ve voltage the electrons will pass throughthe grid,the screen will catching the electrons.The electrons are passing from grid toscreen that why we are calling grid.5.Focussing Grid:

It control the speed of electrons fall on the screen.compared to screen gridlow voltage of negative voltage given to focusiing grid it control focusing so it is calledas focusing grid.6.Screen:

Backside of screen phosphorus coating applied when we give the high voltage

the electron fall on the screen comes from cathode,one spark light appears,finally wegiving voltage to it,that's why we called as final anode or EHT.

Yoke consists of two coils.1.Horizontal deflection coil.2.Vertical deflection coil.

1.Horizontal deflection coils:

IT consists two coils ,in horizontal deflection coil electronic beam scanned in type of"Tracing and retracing".2.Vertical deflection coil:

It consists two coils.in vertical deflection coil electronic beam scanned in typeof vertical traceand vertical retracing.

Horizontal----------left to rightHorizontal----------right to leftVertical trace----- top to bottomVertical retrace--bottom to top

Scanning:with the help of horizontal deflection coil,vertical deflection coil the electron

beam moveto screen from left to right,right to left and top to bottom,botto to top,this process iscalled scanning.In this scanning process the lighting will appear it is called as display.

On this screen the electron beam run slowly from left to rightand run fastfrom right to left,as well as the electron beam run slowly from top to bottom and bottom to top run fastly.


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If vertical oscillator,vertical driver, vertical output components are not working thevertical deflection coils

will noe work because of cannot scanning as vertical.The scanned as horozontal singlehorizontal outputs are not

working cannot display on monitor.

If horizontal deflection coil or coupling network are open the horizontalscanning is not the singlevertical line appear.

For identification of horizontal deflection,vertical deflection coil we checkthe continuity between twocoils on the multimeter,if the high resistance is display on multimeter that coils arevertical deflection coil,if low resistance is display that coils are horizontal deflection coils.

saleem Monitor 9

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