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.OKIA $ISPLAY 0RODUCTS /Y 0 /"OX &). 3ALO &INLAND
#HASSIS :
(IGH 2ESOLUTION #OLOR -ONITOR
#ONTENTS
3ERVICE #IRCUIT $ESCRIPTION -ONITOR $ISMANTLING 0ART ,IST 0#" 0ART ,IST 0#" ,AYOUT PICTURES
,EVEL
-AIN "OARD MODULE 3-!$ #24 MODULE 3-($
7HEN RE ORDERING MANUALS PLEASE QUOTE THE MODEL NAME AND PART NUMBER
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3ERVICE
#ONTENTS
0RODUCT /VERVIEW 4ECHNICAL 3PECIFICATIONS 0RESET $ISPLAY -ODES -ONITOR #ONNECTION !UDIO &EATURES !UDIO (EADPHONES -ICROPHONE 5SERS #ONTROLS 0OWER SWITCH .ORMAL /PERATIONS 3HIFT /PERATIONS 3ITE 0REPARATION ,OCATION 4ROUBLESHOOTING #HECKING THE /PERATION OF 0OWER 3AVER #ONTROLLING THE -EMORY FOR 0ICTURE !DJUSTMENTS -EMORY FOR 5SER !DJUSTMENTS !DJUSTMENT 2ESETTING THE 5SER MADE SETTINGS FOR GEOMETRY OR IMAGE -EMORY FOR &ACTORY !DJUSTMENTS !DJUSTMENT 3ERVICE -ODE 'ROUPING OF THE ADJUSTMENTS 3ERVICE -ENU !CCESS TO THE 3ERVICE -ODE 'EOMETRY !CCESS TO THE 3ERVICE -ODE 6IDEO )NITIALIZING THE 2EPLACEMENT )# )# ON 3-! 3TORING AND 2ETURNING TO THE 5SER -ODE 7ORKSHOP -AINTENANCE )MPORTANT 3AFETY .OTICE $ISCHARGING THE #24 %3$ 3ENSITIVE 0ARTS 4EST %QUIPMENT 4EST 0ATTERNS $ISASSEMBLY 3TAND ASSEMBLY #ABINET !DJUSTMENT 0ROCEDURE !DJUSTMENT &LOW $IAGRAM 0RELIMINARY 0REPARATIONS 0RELIMINARY 0ICTURE !DJUSTMENTS (IGH 6OLTAGE #OARSE WIDTH 'EOMETRY 'REY 3CALE 4HE -OST 3ENSITIVE #OLOUR ,OW ,IGHT (IGH ,IGHT -AXIMUM-INIMUM #ONTRAST &OCUS #ONVERGENCE -EASURING #ONDITIONS #ONVERGENCE -EASURING 'AUGE 3TATIC #ONVERGENCE $YNAMIC #ONVERGENCE !LLOWED %RROR ,EVELS FOR #ONVERGENCE #OLOUR 0URITY
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0RODUCT /VERVIEW
: IS A INCH MONITOR 4HE MAXIMUM RESOLUTION OF X MAKES THE MONITOR SUITABLE FOR 0# APPLICATIONS USING GRAPHICAL USER INTERFACES 4HE MONITOR HAS AN OWN POWER SUPPLY WITH INPUT VOLTAGE REQUIREMENTS FROM 6 TO 6
4ECHNICAL 3PECIFICATIONS
#ATHODE 2AY 4UBE IN DIAGONAL DEFLECTION ANGLE $ARK ANTIGLARE SPIN COATING 3HORT PERSISTENCE 0 $OT PITCH MM 0ICTURE 3IZE MM X MM WITH SPECIFIED GEOMETRIC DISTORTION -AXIMUM 0ICTURE 3IZE MM X MM DIAGONALLY MM 0OWER )NPUT 2EQUIREMENTS 6OLTAGE 6 (Z !UTOSENSE #URRENT ! 6 ! 6 )NRUSH CURRENT MAX ! PEAK 0OWER $ISSIPATION 7 .ORMAL /PERATION ~ 7 3TAND BY 7 3USPEND 7 !CTIVE OFF -EMORY ,OCATIONS FOR FACTORY PRESET TIMINGS IN USE FREE FOR USER ADJUSTED TIMINGS 'EOMETRIC $ISTORTION 4HE DISTANCE BETWEEN BEZEL AND ACTIVE SCREEN EDGE SHALL NOT VARY MORE THAN MM IN BOTH VERTICAL AND HORIZONTAL DIMENSIONS ,UMINANCE -IN CDM AT CENTER WITH FULL WHITE FIELD 6IDEO )NPUT )NPUT 3IGNAL 2'" ANALOG POSITIVE MAX 6 ¬ (ORIZONTAL ADDRESSABILITY DOTS MAXIMUM 6ERTICAL ADDRESSABILITY DOTS MAXIMUM 3YNCHRONIZATION 2ANGE (ORIZONTAL K(Z TO K(Z AUTOMATIC 6ERTICAL (Z TO (Z AUTOMATIC 3YNCHRONIZATION 3IGNAL 3EPARATE 44, POSITIVENEGATIVE #OMPOSITE 44, POSITIVENEGATIVE -AX $OT &REQUENCY #APABILITY -(Z 4EMPERATURE /PERATING # TO # 0ACKED # TO # (UMIDITY /PERATING TO 0ACKED TO 7EIGHT KG NET KG GROSS 3IZE 4ILT AND 3WIVEL
$IMENSIONS -ONITOR H W D 0ACKAGE ( 7 $
MM MM MM MM MM MM
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!UDIO
!UDIO /UTPUT POWER !MPLIFIER 2-3 POWER )NPUT LEVEL ,INE LEVEL INPUT AT CLIPPING (EADPHONE IMPEDANCE
7 6RMS 6PP OHM
-ICROPHONE -IC AMPLIFIER GAIN D" -IC OUTPUT LEVEL ADJUSTABLE 6PP %XTERNAL -IC INPUT TYPE DYNAMIC CAPACITIVE 3PEAKER .OMINAL POWER 7 .OMINAL )MPEDANCE OHM &REQUENCY RANGE USEABLE AREA (Z K(Z .UMBER OF ELEMENTS TWO PCS 4YPE OF ELEMENT &ULLRANGE %NCLOSURE S TYPE "ACKDAMPED FREE AIR BOX
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0RESET $ISPLAY -ODES
&ULL INTENSITY 6
2IGHT "ORDER
,EFT "ORDER
6IDEO
"LANKING 6
( "LANKING ( &RONT 0ORCH
( !CTIVE 6IDEO ( "ACK PORCH
( 3YNC 3IGNAL
( 3YNC
&ULL INTENSITY
"OTTOM "ORDER
6
5PPER "ORDER
6IDEO
"LANKING 6
6 "LANKING 6 &RONT 0ORCH
6 !CTIVE 6IDEO 6 "ACK 0ORCH
6 3YNC 3IGNAL
6 3YNC
$ISPLAY -ODE -EMORY LOCATION $ISPLAY -ODE .AME ( &REQUENCY K(Z ( 0ERIOD¿S ( !CTIVE 6ID
EO¿S ( 2ESOLUTION ( 3YNC¿S ( "ACK 0ORCH¿S 6 &REQUENCY(Z 6 0ERIOD,INES 6 2ESOLUTION 6 3YNC,INES 6 "ACK 0ORCH ,INES ( SYNC 0OLARITY 6 SYNC 0OLARITY 6 &RONT 0ORCH ,INES $OT &REQUENCY -(Z )NTERLACING
.#% NO
.#% NO
.#%
.#%
.#% NO
.#% NO
.#%
.#%
.#%
( &RONT 0ORCH¿S
NO
NO
NO
NO
NO
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-ONITOR #ONNECTION
-AKE SURE THAT THE MONITOR IS DISCONNECTED FROM MAINS AND THE POWER SWITCHES OF THE COMPUTER AND ALL ATTACHED DEVICES ARE TURNED OFF BEFORE CONNECTING THE MONITOR #ONNECT THE SIGNAL CABLE PLUG TO THE VIDEOCONTROLLER CONNECTOR AT THE BACK OF THE COMPUTER 4IGHTEN THE SCREWS ON THE PLUG BY HAND #ONNECT THE POWER CORD FIRST TO THE MONITOR AND THEN TO A GROUNDED POWER OUTLET
0OWER CORD
)F YOUR MONITOR IS $$# COMPATIBLE 0#
$O NOT USE ANY ADAPTER WHEN CONNECTING SIGNAL CABLE TO YOUR COMPUTER $O NOT EXTEND THE SIGNAL CABLE WITH EXTENSION LEAD 4HE $$# SIGNALS WILL NOT ACCEPT EXTENDED CABLE
4O GROUNDED POWER OUTLET 6 (Z 3CREW
)F THERE IS NO $$# IN YOUR COMPUTER 0#
.ORMALLY THERE IS NO NEED FOR ADAPTOR WHEN CONNECTING SIGNAL CABLE TO YOUR COMPUTER
$ISPLAY $ATA #HANNEL $$# 0LUGèNè0LAY 0N0
4HE DATA CHANNEL IS INTENDED TO SIMPLIFY MONITOR INSTALLATION 4HE MONITOR SENDS TO THE COMPUTER DETAILS OF ITS CAPABILITIES 5SING THIS INFORMATION THE COMPUTER MAY CONFIGURE ITS DISPLAY DRIVER TO MAKE BEST USE OF THE MONITOR S FEATURES
3IGNAL CABLE PLUG 4O VIDEO CONTROLLER CONNECTION IN COMPUTER
.OTE
9OUR MONITOR OPERATES ACCORDING TO THE 6%3! $$# LEVEL !" /NLY COMPUTERS THAT SUPPORT THE SAME GUIDELINES AND OPERATE AT THE SAME OR A HIGHER LEVEL CAN MAKE USE OF THIS FEATURE )F YOUR COMPUTER DOES NOT SUPPORT THE RELEVANT GUIDELINES YOU CAN STILL USE YOUR MONITOR AND COMPUTER 9OU MAY NEED TO SPECIFY MANUALLY THE APPROPRIATE RESOLUTION IN THE COMPUTER
3IGNAL CONNECTOR
0IN 3IGNAL 26 '6 "6 '.$ 3GND 2GND 'GND "GND 3YNCGND '.$ 3$! (SYNC 6S 3#, 2ED VIDEO 'REEN VIDEO "LUE VIDEO 'ROUND 'ROUND RETURN FOR SERIAL DATA INOUT 2ED VIDEO GROUND RETURN 'REEN VIDEO GROUND RETURN "LUE VIDEO GROUND RETURN .O #ONNECTION 3YNC RETURN 'ROUND $$# DATA )/ (ORIZONTAL SYNC 6ERTICAL SYNC $$# CLOCK INPUT
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!UDIO &EATURES
-ONITOR HAS BUIL IN BASIC AUDIO FEATURES THE SOUND SYSTEM IS CAPABLE OF PRODUCING STEREO SOUND VIA 2 AND , LOUDSPEAKERS )F THE AUDIO SIGNAL INPUT LEVEL EXCEEDS THE SPECIFIED RANGE THE ACOUSTIC WAVES MAY CAUSE DISTURBANCIES IN THE PICTURE WITH HIGH 6/,5-% SETTING 4HE PICTURE RETURNS TO NORMAL BY REDUCING THE SOUND VOLUME
!UDIO
4HERE ARE TWO 2#! CONNECTORS FOR LINE LEVEL !5$)/ ). IN REAR OF THE MONITOR
(EADPHONES
4HERE IS MM (%!$0(/.% /54 SOCKET FOR AUDIO OUT FOR W HEADPHONE CONNECTION IN FRONT SIDE OF CORNER USAGE WILL SWITCH OFF INTERNAL SPEAKERS
-ICROPHONE
4HERE IS MM %84%2.!, -)#2/0(/.% ). CONNECTION IN FRONT SIDE OF CORNER USAGE WILL SWITCH OFF INTERNAL MICRO
PHONE 4HERE IS MM -)#2/0(/.% /54 SOCKET IN REAR OF THE MONITOR
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5SER #ONTROLS
0OWER 3WITCH 4URNING THE -ONITOR /. AND /&&
0USH THE POWER SWITCH TO TURN THE MONITOR ON OR OFF 7HEN THE POWER IS TURNED ON THE POWER ON INDICATOR WILL LIGHT 0OWER ON INDICATOR
'REEN 4HE MONITOR IS IN NORMAL OPERATION "LINKING 4HE MONITOR IS IN 0OWER OFF STATE .OT ILLUMINATED 4HE MONITOR IS TURNED OFF WITH POWER SWITCH OR DISCONNECTED FROM MAINS OUTLET 0OWER SWITCH
)F THE POWER MANAGEMENT FUNCTION WORKS PROPERLY IN YOUR COMPUTER YOU DO NOT NEED TO SWITCH THE MONITOR ON OR OFF )T HAPPENS AUTOMATICALLY 4HE POWER SWITCH DOES NOT DISCONNECT THE MONITOR FROM MAINS )N ODER TO MAKE THE MONITOR COMPLETELY POWERLESS UNPLUG THE POWER CORD FROM POWER OUTLET
.ORMAL /PERATIONS
6OLUME (OR #ENTRING 7IDTH $EGAUSS
3PEAKER /./&& 6ERT #ENTRING (EIGHT
"RIGHTNESS #ONTRAST
0USH 2%3%4
BUTTON DOWN TO RETURN TO THE FACTORY SETTINGS :
3HIFT /PERATIONS
&IRST PUSH THE SHIFT BUTTON AND HOLD IT DOWN DURING ADJUSTMENT OF SHIFT OPERATIONS /RTHOGONALITY %7 !MPL
4RAPEZOID #OLOR 2ESET
#OLOR TEMPERATURE
-OIRE -IC -UTE
-IC ,EVEL
0USH 2%3%4
BUTTON DOWN TO RETURN TO THE FACTORY SETTINGS
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3ITE 0REPARATION
,OCATION
4HIS -ONITOR IS DESIGNED FOR NORMAL OFFICE CONDITIONS )T IS EQUIPPED WITH OWN POWER SUPPLY )T IS NOT TO BE SERVICED OR REPAIRED ON SITE
4ROUBLESHOOTING
,OCAL SERVICE FACILITIES SHOULD PERFORM SIMPLE MAINTENANCE SUCH AS TRIMMING -ORE ADVANCED MAIN
TENANCE AND REPAIR THAT REQUIRES REPLACEMENT OF COMPONENTS WHICH IN TURN REQUIRES TESTING AND RE
TRIMMING SHOULD BE CARRIED OUT IN A CENTRAL WORKSHOP
3YMPTOM 0ICTURE SCREEN IS BLANK 4HE INDI
CATOR ON THE FRONT PANEL IS NOT ILLUMI
NATED 4HE INDI
CATOR ON THE FRONT TH F T PANEL IS IL
LUMINATED -EASURES #HECK THAT THE POWER CORD IS CORRECTLY CONNECTED TO THE MONITOR AND TO THE POW
ER OUTLET IF THE MONITOR IS POWERED THROUGH THE COMPUTER CHECK THAT THE COMPUT
ER IS SWITCHED ON WITH THE MAINS SWITCH 5SE A DESK LIGHT FOR EXAMPLE TO VERIFY THAT CURRENT IS CONNECTED TO A POWER OUTLET )F NO ELECTRICITY IS CONNECTED TO THE OUTLET CALL AN ELECTRICIAN 5NPLUG THE MONITOR FROM POWER OUTLET FOR ABOUT ONE MINUTE 4HE MONITOR MIGHT BE IN STAND BY POSITION 0USH ONE OF THE KEYBOARD BUTTONS OR MOVE THE MOUSE #HECK THAT THE KEYBOARD S CONNECTION TO THE COMPUTER IS /+ #HECK THAT THE SIGNAL CABLE CONNECTOR IS CONNECTED )F THE CONNECTOR IS LOOSE TIGHTEN THE CONNECTOR S SCREWS 5NPLUG THE MONITOR FROM POWER OUTLET FOR ABOUT ONE MINUTE 3WITCH OFF THE MONITOR AND THE COMPUTER 2EMOVE THE SIGNAL CABLE FROM THE COMPUTER 3WITCH ON THE MONITOR USING THE POWER SWITCH )F A GRAY SLIGHTLY BLINKING FRAME BACKGROUND APPEARS ON THE SCREEN IT IS EVIDENT THAT THE MONITOR FUNCTIONS CORRECTLY AND THE PROBLEM IS CAUSED BY AN ERROR IN OTHER PARTS OF THE SYSTEM #HECK THE SIGNAL CABLE S CONNECTION PINS )F THE PINS ARE SLIGHTLY DISTORTED USE NOSE PLIERS TO STRAIGHTEN THEM 4HE COMPUTER MAY USE A TIMING VALUES WHICH ARE OUT OF THE MONITOR S SYNCHRONIZATION RANGE 0ICTURE HAS COLOUR DE
FECTS $EMAGNETIZE THE MONITOR )F COLOUR DEFECT IS REPEATED WITHOUT THE MONITOR HAVING BEEN MOVED IT IS POSSIBLE THAT THE MONITOR IS INFLUENCED BY A STRONG MAGNETIC INTERFERENCE FIELD NEAR TO A HIGH POWER CABLE FOR EXAMPLE 4RY TO FIND A BETTER LOCATION FOR THE MONITOR OR THE INTERFERENCE SOURCE .OTE THAT ANOTHER MONITOR PLACED TOO NEAR LESS THAN CM MAY ALSO GENERATE INTERFERENCE IN THE PICTURE 9OUR COMPUTER MAY USE A TIMING FOR WHICH THE CORRESPONDING PICTURE CHAR
ACTERISTIC ADJUSTMENTS HAVE NOT BEEN SET AT THE FACTORY !DJUST THE PICTURE CHARACTERISTICS -AKE SURE YOUR COMPUTER AND VIDEO CARD ARE PROPERLY CONFIGURED FOR YOUR MONITOR #HECK THE PROXIMITY OF OTHER ELECTRICAL DEVICES THAT GENERATE MAGNETIC FIELDS SUCH AS SPEAKERS OTHER MONITORS ELECTRIC FANS AND FLUORESCENT LIGHT FIXTURES 0ICTURE IS BLACK AND WHITE #HECK THAT THE SIGNAL CABLE S CONNECTOR IS COMPLETELY INSERTED 3WITCH OFF THE COMPUTER AND RESTART
0ICTURE IS STABLE BUT DIS
TORTED 0ICTURE IS UNSTABLE
#HECKING THE /PERATION OF 0OWER3AVER
4HE PROPER OPERATION OF THE FUNCTION REQUIRES A COMPUTER WITH 6%3! $0-3 POWER MANAGEMENT CAPABILITIES .OTE THAT THE POWER SAVING FEATURE MUST BE ACTIVATED IN THE COMPUTER WHEN CHECKING THE OPERATION
3TATE .ORMAL /PERATION 3TAND BY 3USPEND !CTIVE /FF #OLOUR OF THE POWER ON INDICATOR 'REEN 'REEN 'REEN "LINKING 6 9ES 9ES 9ES 9ES 6 9ES 9ES 9ES .O 6 9ES 9ES 9ES .O (IGH 6OLTAGE 6IDEO 9ES 9ES .O .O 9ES .O .O .O
$0-3 $ISPLAY 0OWER -ANAGEMENT 3IGNALING IS A TRADE MARK OF 6IDEO %LECTRONICS 3TANDARD !SSOCIATION 6%3!
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#ONTROLLING THE -EMORY FOR 0ICTURE !DJUSTMENTS
4HE PICTURE ADJUSTMENT VALUES ARE STORED IN NON
VOLATILE MEMORY 4HE MEMORY HAS SEPARATED AREAS FOR 5SER !DJUSTMENTS AND FOR &ACTORY !DJUSTMENTS
-EMORY FOR 5SER !DJUSTMENTS
!DJUSTMENT
)F THERE ARE VALUES AVAILABLE IN THE MEMORY FOR USER ADJUSTMENTS CORRESPONDING TO THE PRESENT TIMING SIGNALS THEY ARE ALWAYS USED .EW USER MADE ADJUSTMENTS ARE STORED TO THE MEMORY FOR USER ADJUSTMENTS
2ESETTING THE 5SER MADE SETTINGS FOR GEOMETRY OR IMAGE
5SER MEMORY CAN BE EMPTIED FROM USER MADE SETTINGS 2ESETTING AFFECTS ONLY THE TIMING WHICH IS CURRENTLY ACTIVE 4HE RESET FUNCTION IS INHIBITED IF NO CORRESPONDING FACTORY PRESET DIS
PLAY MODE EXISTS 0LEASE REFER TO CHAPTER 5SER CONTROLS !FTER RESETTING ALL PICTURE PROPERTIES ARE COMING FROM MEMORY FOR FACTORY ADJUSTMENTS
-EMORY FOR &ACTORY !DJUSTMENTS
!DJUSTMENT &ACTORY ADJUSTMENTS CAN BE UPDATED IN SERVICE MODE )F THERE IS NO LOCATION IN FACTORY ADJUST
MENT MEMORY FOR TIMINGS CURRENTLY IN USE THE ADJUSTMENT AFFECTS THE MEMORY FOR USER ADJUST
MENTS )F THE MEMORY LOCATION MENTIONED IN CASE IS EMPTY THE PICTURE ADJUSTMENT VALUES ARE READ FROM MEMORY FOR FACTORY ADJUSTMENTS &ACTORY ADJUSTMENTS CORRESPONDING TO THE CURRENT TIM
INGS ARE TRANSFERRED TO USER MEMORY IF ANY PICTURE PROPERTY IS ADJUSTED !FTER THAT THE OPERATION IS AS IN CASE
4HE MEMORY CAN BE UPDATED IN 3ERVICE -ODE 2EFER TO THE CHAPTER ì3ERVICE -ODEì 4HE MEMORY CAN BE UPDATED IN 5SER -ODE
3TORING )NITIALIZATION
-EMORY FOR &ACTORY !DJUSTMENTS 3-! )#
0RESET 2ECALL 'EOMETRY IMAGE
-EMORY FOR 5SER !DJUSTMENTS 3-! )#
-EMORY FOR "ASIC !DJUST
MENTS 6'!
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3ERVICE -ODE
3ERVICE -ODE IS NEEDED FOR UPDATING OF THE FACTORY ADJUSTMENTS FOR TIMINGS LISTED IN THE CHAPTER 0RE
SET $ISPLAY -ODES )F THERE IS NO LOCATION IN FACTORY ADJUSTMENT MEMORY FOR DISPLAY MODE CURRENTLY IN USE THE ADJUSTMENT AFFECTS THE MEMORY FOR USER ADJUSTMENTS !CTIVATE 3ERVICE -ODE !,7!93 IN K(Z (Z .#% MODE !FTER INITIALIZING ALSO ADJUST THE MODE K(Z (Z .#% FIRST !FTER THAT MODE CAN BE CHANGED IN CERTAIN ORDER WHICH IS FOUND IN PAGE )F THE CERTAIN MODE IS WANT TO ADJUSTED THE ORDER IN PAGE MUST BE FOLLOWED &OR %XAMPLE BEFORE -EMORY ,OCATION CAN BE ADJUST YOU MUST GO THROUGH ,OCATIONS AND
'ROUPING OF THE !DJUSTMENTS
4HERE ARE TWO GROUPS OF SOFTWARE ADJUSTMENTS IN SERVICE MODE GEOMETRY ADJUSTMENT SET VIDEO ADJUSTMENT SET 4HE FOLLOWING TABLE SHOWS HOW THE ADJUSTMENTS ACT IN RELATION TO THE DISPLAY MODES
!DJUSTMENT
#OMMON FOR ALL $ISPLAY MODES 8 8
3EPARATE FOR EACH $ISPLAY MODE
!VAILABLE IN 5SER -ODE 8
!VAILABLE IN 3ERVICE -ODE
#ONTRAST "RIGHTNESS (ORIZONTAL CENTRING 6ERTICAL CENTRING (EIGHT 7IDTH 0INCUSHION 4RAPEZIUM /RTHOGONALITY 0INCUSHION BALANCE -OIRE (ORIZONTAL RASTER CENTRING ' -AX-IN CONTRAST 2 'AIN " 'AIN
#OMMON MEMORY FOR BOTH MODES
8
#OMMON MEMORY FOR BOTH MODES
8 8 8 8 8 8 8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8 8 8 8 8 8
#OMMON ADJUSTMENTS NEED TO BE ADJUSTED ONLY ONCE 3EPARATE ADJUSTMENT MUST BE PERFORMED FOR EVERY DISPLAY MODE TO BE STORED
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3ERVICE -ODE
!CCESS TO 3ERVICE -ODE 'EOMETRY
&IRST SWITCH /&& THE MONITOR WITH POWER SWITCH 0USH 3()&4 DOWN 7HILE KEEPING 3()&4 DOWN SWITCH /. THE MONITOR 2ELEASE 3()&4 AFTER MONITOR HAS BEEN STARTED
(OR #ENTRING 7IDTH
%NTRY 6ERT #ENTRING (EIGHT
3ERVICE MODE 3HIFT 'EOMETRY
/RTHOGONALITY
%7 !MPL %XIT
4RAPEZOID )NITIALIZING
%7 "ALANCE
2ASTER
:
!CCESS TO 3ERVICE -ODE 6IDEO
&IRST SWITCH /&& THE MONITOR WITH POWER SWITCH 0USH 2%3%4 DOWN 7HILE KEEPING 2%3%4 DOWN SWITCH /. THE MONITOR 2ELEASE 2%3%4 AFTER MONITOR HAS BEEN STARTED
2ED !MPL
"LUE !MPL
' %NTRY
-AX CONTRAST
3ERVICE -ODE 3HIFT 6IDEO
3AVE AND %XIT
-IN CONTRAST
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)NITIALIZING THE 2EPLACEMENT )# ON 3-! BOARD
)F THE MEMORY FOR FACTORY ADJUSTMENTS IS REPLACED IT MUST BE INITIALIZED $URING INITIALIZING ALL MEMORY LOCATIONS ARE WRITTEN WITH APPROXIMATE VALUES 4HEY MUST BE UPDATED IN SERVICE MODE AS EXPLAINED IN THE CHAPTER !DJUSTMENT 0ROCEDURE !CTIVATE SERVICE MODE 'EOMETRY AS EXPLAINED BEFORE 0RESS ).)4)!,):).' BUTTON 7AIT MIN SECONDS 3WITCH /&& THE MONITOR #AUTION )NITIALIZING OF A PROGRAMMED MEMORY )# DELETES ALL USER AND FACTORY MADE ADJUSTMENTS
3TORING AND 2ETURNING TO THE 5SER -ODE
4HE GEOMETRY ADJUSTMENTS ARE STORED IN TWO SECONDS AFTER EACH ADJUSTMENT 6IDEO ADJUSTMENTS ARE STORED AT THE MOMENT WHEN YOU LEAVE 3ERVICE -ODE $ISPLAY MODES CAN BE CHANGED WITHOUT LEAV
ING 3ERVICE -ODE WHEN MAKING DISPLAY MODE RELATED ADJUSTMENTS %XIT FROM 3ERVICE -ODE 6IDEO BY BUSHING 3AVE AND %8)4 BUTTON 7HEN YOU EXIT FROM 3ERVICE -ODE THE MONITOR TURNS TO NORMAL USER MODE )F YOU WANT TO LEAVE THE SERVICE MODE WITHOUT MEMORIZING 6IDEO ADJUSTMENTS SWITCH OFF THE MONITOR IN SERVICE MODE
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7ORKSHOP -AINTENANCE
)MPORTANT 3AFETY .OTICE
4HE COMPONENTS WHICH ARE IMPORTANT FOR SAFETY ARE MARKED WITH SPECIAL MARK ON THE CIRCUIT DIA
GRAM )T IS ESSENTIAL THAT THESE CRITICAL PARTS SHOULD BE REPLACED WITH MANUFACTURE S SPECIFIED PARTS TO PREVENT 8 RADIATION SHOCK FIRE OR OTHER HAZARDS &OR YOUR OWN SAFETY USE ALWAYS SAFETY ISOLATING TRANSFORMER WHEN REPAIRING THE MONITOR
$ISCHARGING THE #24
(IGH VOLTAGE CIRCUITRY INCLUDES BLEEDER RESISTOR WHICH NORMALLY DISCHARGES THE TUBE IN ABOUT SE
CONDS AFTER THE POWER IS SWITCHED OFF )F YOU FOR SAFETY REASONS WANT TO BE SURE ABOUT THE DIS
CHARGING DO AS FOLLOWS 7EAR SAFETY GOGGLES ! CRACKED #24 MAY IMPLODE WHEN DISCHARGED 4HE SIGNAL CABLE MUST BE DISCONNECTED FROM THE COMPUTER 4O DISCHARGE THE #24 A FLAT HEAD SCREWDRIVER WITH GROUNDING CABLE IS REQUIRED $ISCONNECT THE POWER CABLE #ONNECT THE METAL CHASSIS OF THE MONITOR TO RELIABLE EARTH #ONNECT THE GROUNDING WIRE TO THE SCREWDRIVER #ONNECT THE OTHER END OF THE GROUNDING WIRE TO THE CHASSIS EARTH )NSERT THE SCREWDRIVER UNDER THE RUBBER CAP OF THE %(4 CONNECTOR TO DISCHARGE THE TUBE
%3$ 3ENSITIVE 0ARTS
4O PREVENT DAMAGE WHEN WORKING WITH ELECTROSTATIC DISCHARGE %3$ SENSITIVE PARTS OBSERVE THE FOLLOWING INSTRUCTIONS +EEP THE %3$ SENSITIVE PART IN ITS ORIGINAL SHIPPING CONTAINER UNTIL YOU ARE READY TO INSTALL THE PART INTO THE COMPONENT CARD *UST BEFORE TOUCHING THE %3$ SENSITIVE PART DISCHARGE TO THE MONITOR ANY STATIC ELECTRICITY IN YOUR BODY DO THIS BY TOUCHING THE METAL FRAME OR COVER OF THE MACHINE )F POSSIBLE KEEP ONE HAND ON THE FRAME WHEN INSERTING OR REMOVING A LOGIC CARD FOR EXAMPLE (OLD THE %3$ SENSITIVE PART BY ITS EDGE DO NOT TOUCH ITS PINS
4EST %QUIPMENT
4HE FOLLOWING TEST EQUIPMENT ARE REQUIRED TO ADJUSTMENT PROCEDURE 3AFETY ISOLATING TRANSFORMER $IGITAL MULTIMETER &LUKE OR EQUIVALENT TRUE 2-3 MULTIMETER (IGH VOLTAGE PROBE EG &LUKE K 3IGNAL GENERATOR 64' 0# OR PROGRAMMABLE VIDEO GENERATOR #OLOUR ANALYZER EG -INOLTA 46 #OLOUR !NALYZER #! #ONVERGENCE 'AUGE #-!2 OR EQUIVALENT /SCILLOSCOPE -(Z BAND WIDTH (I 0OT TESTER &LASH TESTER WITH INSULATION MEASUREMENT ,EAKAGE CURRENT "REAK DOWN VOLTAGE %3$ PROTECTION NECESSARY
4EST 0ATTERNS
!CTIVE VERTICAL VIDEO TIME
! AREA " AREA
PIXELPIXELPI PIXELPIXELPI PIXELPIXELPI PIXELPIXELPI
!CTIVE HORIZONTAL VIDEO TIME
"LACK 0ICTURE 3IGNAL LEVEL 6 AT EACH 2'" INPUT (IGHLIGHT GREY SCALE TRACKING 3IGNAL LEVEL M6 IN THE WINDOW AT EACH 2'" INPUT #ROSSHATCH 0ICTURE 3QUARES EG MM X MM /UTMOST LINES CORRESPOND THE ACTIVE VERTICALHORIZONTAL VIDEO TIME #ONVERGENCE TEST PATTERN &OCUS TEST PATTERN
:
$ISASSEMBLY
3TAND ASSEMBLY
#ABINET
3ET THE MONITOR ON CUSHION PICTURE TUBE FACING DOWN
,OOSEN AND REMOVE TWO SCREWS /PEN THE PLASTIC PAWL WITH SCREWDRIVER MAXIMUM WIDTH MM
:
!DJUSTMENT 0ROCEDURE
4HE FOLLOWING PROCEDURE MUST BE CARRIED OUT IN CASE OF LARGE SERVICE OPERATIONS EG WHEN A CIRCUIT BOARD OR NONVOLATILE MEMORY )#! HAS BEEN REPLACED BY A NEW ONE 4HE ORDER OF ADJUSTMENTS EXPLAINED HERE HAS BEEN FOUND TO PRODUCE THE DESIRED RESULT WITH THE MINI
MUM OF EFFORT !DJUSTMENTS CAN ALSO BE MADE IN ANOTHER ORDER OR COMPLETELY SEPARATELY
!DJUSTMENT &LOW $IAGRAM
34!24 'RAY SCALE !SSEMBLIES OR COMPONENTS REPLACED ./ 9%3 0ERFORM 0RELIMINARY PREPARATIONS 3EE 4HE MOST SENSITIVE COLOUR 3EE
,OW LIGHT 3EE
(IGH LIGHT 3EE
)#! REPLACED ./ 2ESET USER MEMORY FOR DISPLAY MODES TO BE AD
JUSTED 3EE
9%3 -AXIMUMMINIMUM CONTRAST 3EE
3WITCH /&& THE MONITOR AND AC
TIVATE SERVICE MODE )NITIALIZING
&OCUS 3EE
#ONVERGENCE 3WITCH /&& THE MONITOR !DJUST THE CONVERGENCE IN THE MIDDLE OF THE TUBE WITH STATIC ADJUSTMENTS 3EE
'EOMETRY !CTIVATE SERVICE MODE AND PERFORM PARA WITH K(Z (Z
!DJUST THE CONVERGENCE IN THE CORNERS OF THE TUBE WITH DYNAMIC ADJUSTMENTS 3EE
2ETURN TO THE USER MODE 0ERFORM PARA AND FOR ALL OTHER TIMINGS
34/0
!FTER INITIALIZING ADJUST !,7!93 FIRST K(Z (Z MODE .#% !FTER THAT YOU CAN CHANGE MODE IN CERTAIN ORDER SEE PAGE WITHOUT LEAVING SERVICE MODE
:
0RELIMINARY 0REPARATIONS
#ONNECT THE SIGNAL CABLE TO THE 0# 3WITCH ON THE MONITOR AND THE 0# ,ET THE MONITOR WARM UP FOR MINUTES BEFORE STARTING THE ADJUSTMENTS
0RELIMINARY 0ICTURE !DJUSTMENTS
3ELECT (:(Z .#% CROSSHATCH TEST PATTERN TO MAXIMUM AND ADJUST UNTIL THE BACKGROUND IS FAINTLY VISIBLE 3ET !DJUST FOCUS IF POOR $O NOT ADJUST ' VOLTAGE WITH POTENTIOMETER OR KEYPANEL IF YOU HAVE REASON TO BELIVE THAT THERE IS NO NEED TO ADJUST GRAY SCALE
2EMEMBER
(IGH 6OLTAGE
3ELECT K(Z(Z .#% CROSSHATCH TEST PATTERN #ONNECT THE HIGH VOLTAGE METER TO THE ANODE OF THE PICTURE TUBE !DJUST THE HIGH VOLTAGE TO q K6 WITH 24ON 3-! BOARD
&RONT
3-!
BOARD
24
"ACK EDGE
#OARSE WIDTH
3ELECT K(Z(Z .#% CROSSHATCH TEST PATTERN 3ET WIDTH TO THE CENTER WITH MEMBRANE ADJUSTMENT 3ET WIDTH APPROXIMATELY MM WITH COARSE ADJUSTMENT 24
3-!
BOARD
24
:
'EOMETRY
!CTIVATE 3ERVICE -ODE IN K(Z (Z MODE .#% $EGAUSSING MUST BE CARRIED OUT BEFORE THE PICTURE ADJUSTMENTS $EGAUSSING SHALL BE REPEATED IF THE MONITOR IS MOVED 3ELECT K(Z (Z .#% CROSSHATCH TEST PATTERN TO MAXIMUM AND ADJUST UNTIL THE BACKGROUND IS FAINTLY VISIBLE 3ET 2EDUCE WIDTH UNTIL BOTH VERTICAL EDGES OF THE BACKGROUND ARE VISIBLE #ENTRE THE BACKGROUND 4HIS ADJUSTMENT IS COMMON FOR ALL DISPLAY MODES
MM
!DJUST SIZE POSITION AND SHAPE OF THE PICTURE EQUAL TO THE MASK APER
TURE !DJUST FIRST THE PROPERTIES WITH LARGEST DEVIATION FROM THE CORRECT VALUE 3ELECT K(Z (Z .#% CROSSHATCH PATTERN !DJUST FINAL WIDTH AND HEIGHT
MM
2EPEAT STEPS AND FOR EVERY DISPLAY MODE TO BE STORED .OTE THAT THE DISPLAY MODE CAN BE CHANGED IN CERTAIN ORDER SEE PAGE WITHOUT LEAVING THE SERVICE MODE
(OR #ENTRING 7IDTH
3ERVICE MODE 'EOMETRY
%NTRY
6ERT #ENTRING
(EIGHT 3ERVICE MODE 3HIFT 'EOMETRY %XIT
/RTHOGONALITY
%7 !MPL
4RAPEZOID )NITIALIZING
%7 "ALANCE
2ASTER
:
'REY 3CALE
4HE GREY SCALE IS ADJUSTED FOR + COLOUR TEMPERATURE !CTIVATE 3ERVICE -ODE 6IDEO IN K(Z (Z .#% MODE
4HE -OST 3ENSITIVE #OLOUR
4HE MOST SENSITIVE COLOUR HAS BEEN MARKED IN A LABEL ON THE DEFLECTION YOKE )T MAY NOT BE CORRECT IF TUBE OR 3-( CARD HAS BEEN CHANGED )N THAT CASE JUDGE THE MOST SENSITIVE COLOUR FROM THE TONE OF THE PICTURE AFTER YOU HAVE MADE THE FOLLOWING ADJUSTMENTS 3ELECT K(Z (Z .#% BLACK TEST PATTERN TO MAXIMUM 3ET AND 3ET 2%$'2%%.",5% "LACK ,EVEL TRIMMER ADJUSTMENTS MAXIMUM 6 24( 24( 24( 3ET ' ADJUSTMENT TO CENTER 0LACE THE PROBE OF THE COLOUR ANALYZER IN THE MIDDLE OF THE SCREEN AND ADJUST WITH ' TRIMMER UNTIL THE PICTURE BRIGHTNESS TO q NIT
,OW ,IGHT
3ELECT K(Z (Z .#% BLACK TEST PATTERN !DJUST PICTURE BRIGHTNESS TO q NITS WITH ' ADJUSTMENT !DJUST WITH ADJUSTMENT THE BRIGHTNESS TO q NITS !DJUST THE COLOUR COORDINATES TO + X q Y q WITH 2%$'2%%.",5% "LACK ,EVEL ADJUSTMENTS $O NOT ADJUST THE MOST SENSITIVE COLOUR TO THE MAXIMUM AND CHECK THAT THE BRIGHTNESS IS STILL 3ET AND q NITS )F NOT REPEAT STEPS AND
&/#53
'
,EFT SIDE VIEW OF THE CHASSIS
(IGH ,IGHT
3ELECT K(Z (Z .#% BLACK TEST PATTERN !DJUST WITH THE PICTURE BRIGHTNESS TO q NITS 3ELECT K(Z (Z .#% WINDOW TEST PATTERN THE PICTURE BRIGHTNESS IN THE WINDOW TO q NITS !DJUST WITH !DJUST WITH 2%$",5% AMPL THE COLOUR COORDINATES IN THE WINDOW TO X q Y q #HECK AFTER ADJUSTMENT THAT THE BRIGHTNESS READING IS IN LIMITS #HECK PARA AND 2EADJUST COLOR TEMPERATURE IF OUT OF TOLER
ANCE
-AXIMUM-INIMUM #ONTRAST
3ET TO THE MAXIMUM THE PICTURE BRIGHTNESS OUTSIDE WINDOW TO q NITS !DJUST WITH !DJUST BRIGHTNESS IN THE WINDOW TO q NITS WITH -!8 #/.42 TO MINIMUM 3ET !DJUST BRIGHTNESS TO q NITS WITH -). #/.42 %XIT SERVICE MODE
&OCUS
3ELECT K(Z (Z .#% CROSSHATCH TEST PATTERN 3ET TO THE MAXIMUM AND ADJUST UNTIL THE BACKGROUND IS FAINTLY VISIBLE !DJUST THE SHARPNESS WITH &/#53 TRIMMERS TO OPTIMUM !DJUST UNTIL THE BACKGROUND IS INVISIBLE 3ELECT FOCUS TEST PATTERN #HECK THAT ALL LETTERS ARE CLEARLY VISIBLE
PIXELPIXELPI PIXELPIXELPI PIXELPIXELPI PIXELPIXELPI
:
#ONVERGENCE
2EDUCE FIRST THE CONVERGENCE ERROR IN THE MIDDLE OF THE SCREEN TO MINIMUM USING STATIC ADJUSTMENTS !FTER THE CONVERGENCE IS FAULTLESS IN THE MIDDLE OF THE TUBE USE DYNAMIC ADJUSTMENTS TO ELIMINATE THE ERROR IN THE EDGES OF THE TUBE 3TATIC ADJUSTMENTS AFFECTS THE WHOLE PICTURE AREA MAGNET RING SET ON THE TUBE NECK HORIZONTAL VERTICAL $YNAMIC ADJUSTMENTS AFFECTS A PART OF THE PICTURE AREA DEFLECTION YOKE TRIMMERS
-EASURING #ONDITIONS
!DJUST CONVERGENCE WITH K(Z .#% LINE FREQUENCY -AKE SURE THAT FOCUS IS CORRECTLY SET AT THE MID
POINT BETWEEN THE SCREEN CENTER AND THE EDGE OF THE PICTURE 5SE WHITE CROSSHATCH TEST PATTERN WITH CIRCLE !DJUST TO NEAR THE MAXIMUM AND REDUCE UNTIL THE BACKGROUND DISAPPEARS
#ONVERGENCE -EASURING 'AUGE #-!2
4HE USE OF THE +LEIN #-!2 #ONVERGENCE 'AUGE HAS BEEN EXPLAINED HERE BUT OTHER TYPES OF GAUGES CAN BE USED AS WELL #HECK THAT THE ADJUSTING KNOBS ! " ARE SET TO ZERO 0LACE THE GAUGE ON THE LINE WITH MARKING 9 UP UPWARDS WHEN MEASURING HORIZONTAL LINE 0LACE THE GAUGE ON THE LINE WITH MARKING 8 UP UPWARDS WHEN MEASURING VERTICAL LINE )F THE LINE HAS CONVERGENCE ERROR THE LINE IN THE WINDOW SEEMS TO BE BROKEN 5SE KNOBS ! AND " TO ADJUST THE LINE CONTINUOUS )F THE READINGS ARE ON THE OPPOSITE SIDE OF ZERO THE CONVERGENCE ERROR IS !" EG )F THE READINGS ARE ON THE SAME SIDE OF ZERO THE CONVERGENCE ERROR IS EQUAL TO ! IF ! " OR " IF " ! 8 " 9
"LUE
2ED
'REEN
!
3TATIC #ONVERGENCE
4HE MAGNET RINGS HAS BEEN SET TO THE OPTIMUM IN THE FACTORY 2EADJUSTMENT IS NECESSARY ONLY IN CASE THE ADJUSTING MAGNETS HAVE BEEN ACCIDENTALLY MOVED !DJUST ' VERTICALLY IN THE MIDDLE BETWEEN 2 AND " WITH POLE MAGNET RINGS !DJUST ' HORIZONTALLY IN THE MIDDLE BETWEEN 2 AND " WITH POLE MAGNET RINGS !DJUST 2 AND " VERTICALLY TO THE SAME POSITION WITH ' LINE WITH POLE MAGNET RINGS !DJUST 2 AND " HORIZONTALLY TO THE SAME POSITION WITH ' LINE WITH POLE MAGNET RINGS ,OCK THE RINGS WITH PAINT ' 2
2OTATING BOTH RINGS TOGETHER
"
0URITY MAGNET RINGS $O NOT ADJUST POLE MAGNET RINGS POLE MAGNET RINGS
3-(
3LIDING TWO RING TOBS TOWARD OR AWAY FROM EACH OTHER
:
$YNAMIC #ONVERGENCE
0URITY MAGNET RINGS $O NOT ADJUST
2 " 2" 2 "
" 2 2" " 2
2'" 2'" 2'"
"2 "2 "2
2 " 2" 2 "
2" 2" 2"
"2 " 2" 2
2 " 2 " 2 " " 2 " 2 " 2
2"
2"
2" 2" 2"
2 " 2" 2 "
! AREA " AREA
!LLOWED %RROR ,EVELS FOR #ONVERGENCE
&OR HORIZONTAL SYNC FREQUENCIES ABOVE K(Z !REA ! Ì MM !REA " Ì MM
&OR HORIZONTAL SYNC FREQUENCIES BELOW K(Z !REA ! Ì MM !REA " Ì MM
#OLOUR 0URITY
$O NOT MOVE PURITY MAGNET RINGS )F THE PURITY MAGNET RINGS ARE FOUND TO HAVE MOVED DURING TRANS
PORTATION OR HANDLING SET THEM JUST IN THE ORIGINAL POSITION BY TRACING THE LOCKING PAINT PUT ON PURITY MAGNET RINGS AND HOLDER OF BEAM BENDER AND THEN READJUST THE STATIC CONVERGENCE :
#IRCUIT $ESCRIPTION
#HASSIS :
ì (IGH 2ESOLUTION #OLOR -ONITOR
#IRCUIT $ESCRIPTION #IRCUIT $IAGRAMS
7HEN RE
ORDERING MANUALS PLEASE QUOTE THE MODEL NAME AND PART NUMBER
:"
:
#ONTENTS
'ENERAL FEATURES 4HE BLOCK DIAGRAM 4HE POWER SUPPLY 4HE POWER SAVE FUNCTION 4HE DEFLECTION DRIVER 4HE WIDTH CONTROL CIRCUIT 4HE HIGH VOLTAGE GENERATOR 4HE VERTICAL OUTPUT STAGE 4HE HORIZONTAL OUTPUT STAGE 4HE BLANKING CIRCUIT /THER FUNCTIONS $$# !UDIO STAGE 4HE MICROPROCESSOR 4HE VIDEO AMPLIFIER
4HE POWER SUPPLY
'ENERAL FEATURES 4HE START
UP 4HE SYNCHRONIZING 4HE VOLTAGE REGULATION 3LOPE COMPENSATING 4HE OVER CURRENT CONTROL 4HE PRIMARY CURRENT LOCKOUT 4HE SECONDARY CURRENT LOCKOUT 4HE 56,/ SIGNAL
4HE POWER SAVE FUNCTION
'ENERAL /N
MODE 3TAND BY
MODE 3USPEND
MODE 0OWER OFF MODE
4HE DEFLECTION DRIVER
'ENERAL "LOCK DIAGRAM 4HE LINE FREQUENCY BLOCKS 4HE FIELD FREQUENCY BLOCKS 4HE PROTECTION FUNCTIONS &UNCTION IN PRACTICAL SWITCHING 4HE SUPPLY VOLTAGE 4HE SYNCHRONIZING 4HE FORCED CONTROL OF MAXIMUMMINIMUM FREQUENCY 4HE (
$RIVE OUTPUT 4HE PHASE ADJUSTMENT 4HE COMPORTMENT WHEN CHANGING FREQUENCY 4HE VERTICAL DEFLECTION CONTROL 4HE PICTURE HEIGHT 4HE VERTICAL CENTERING 4HE GEOMETRY ADJUSTMENTS %7 AND TRAPEZIUM ADJUSTMENTS
:
%7 BALANCE AND ORTHOGONALITY
4HE WIDTH CONTROL CIRCUIT
'ENERAL &UNCTION 7IDTH ADJUSTMENT AND %7
TRAPEZIUM CORRECTION 4HE CURRENT LOCKOUT
4HE HIGH VOLTAGE GENERATOR
'ENERAL &UNCTION 4HE 3*
DRIVER 4HE REGULATION 4HE CURRENT LIMITING 3TART
UP SITUATION 4HE '
VOLTAGE GENERATION STAGE 8
RAY PROTECTION
4HE VERTICAL OUTPUT STAGE
'ENERAL 4HE FUNCTION
4HE LINE OUTPUT STAGE
'ENERAL FEATURES 4HE FUNCTION ,INEARITY CORRECTION &RAME CENTERING
4HE BLANKING CIRCUIT
4HE LINE BLANKING 4HE VERTICAL BLANKING
/THER FUNCTIONS
4HE BEAM CURRENT LIMITER CIRCUIT 4HE 4#/ COMPENSATING CIRCUIT 4HE RESET CIRCUIT 4HE CLAMP PULSE PRODUCTION 4HE -OIRE ADJUSTMENT 4HE DEMAGNETIZATION CIRCUIT
$$#
'ENERAL $$# LEVELS $$# PRACTICAL CIRCUIT
:
!UDIO
4HE AUDIO AMPLIFIER 4HE MICROPHONE AMPLIFIER
4HE PROCESSOR
4HE HANDLING OF SYNC PULSES 4HE KEYPAD READING 4HE POWER SWITCH 4HE ,%$ CONTROL AND ,ED?BAR FUNCTION /THER PROCESSOR CONNECTIONS
4HE VIDEO AMPLIFIER
4HE PRE
AMPLIFIER 4HE OUTPUT STAGE 4HE BLACK LEVEL CLAMP AND ADJUSTMENT CIRCUIT 4HE BRIGHTNESS ADJUSTMENT CIRCUIT
:
)NTRODUCTION
'ENERAL FEATURES
4HIS IS AN AUTOSYNC
TYPE MICROPROCESSOR CONTROLLED ë COLOR MONITOR 4HE HORIZONTAL FREQUENCY RANGE IS õ K(Z AND THE VERTICAL FREQUENCY RANGE õ (Z WITH A MAXIMUM RESOLUTION OF X 4HE MONITOR HAS BEEN DESIGNED TO OPERATE WITH SEPARATE 44,
LEVEL HORIZONTAL AND VERTICAL SYNC PULSES AND WITH COMPOSITE SYNC 4HE MONITOR OPERATES ON A MAINS VOLTAGE RANGE OF õ 6!# (Z 4HE POWER SUPPLY OF THE MONITOR HAS BEEN DESIGNED TO OPERATE ON THE WHOLE VOLTAGE RANGE SO THERE IS NO NEED FOR A SEPARATE VOLTAGE SWITCH 4HE MONITOR HAS 6%3!
STANDARD 0OWER 3AVE MODES 7ITH THE HELP OF A MEMBRANE KEYPAD LOCATED ON THE FRONT PANEL OF THE MONITOR THE USER CAN ADJUST VARIOUS FACTORS AFFECTING THE IMAGE QUALITY LIKE THE IMAGE SIZE GEOMETRY COLOR TEMPERATURE ETC 4HE MONITOR RECOGNIZES THE USED MODE WITH THE HELP OF THE 6
AND ( SYNC PULSE FREQUENCY AND THE POLARITY OF THE 6
SYNC PULSES )F A MEMORY LOCATION HAS BEEN CREATED FOR THE SETTING THAT IS IF IT IS A SO
CALLED FACTORY SETTING THE PICTURE SIZE AND GEOMETRY ARE AUTOMATICALLY ADJUSTED TO THE OPTIMUM )F THE MONITOR DOES NOT RECOGNIZE THE USED SETTING THAT IS IF THE SETTING HAS NOT BEEN OPTIMIZED THE USER CAN EASILY ADJUST HIMSELF THE PICTURE WITH THE MEMBRANE KEYPAD 4HIS ëNEWì SETTING IS AUTOMATICALLY SAVED IN THE MONITORèS MEMORY TO BE READY FOR THE NEXT SESSION 4HE MONITOR DOES NOT HAVE A SWITCH CUTTING OFF THE MAINS VOLTAGE BUT A SO
CALLED SLEEP SWITCH WHICH DOES NOT CUT OFF THE MONITORèS POWER SUPPLY BUT ONLY SOME OF THE VOLTAGES IN THE SECONDARY SIDE OF THE POWER SUPPLY
)MPORTANT 4HE MONITORèS POWER SUPPLY IS OPERATIONAL WHEN THERE IS A MAINS CURRENT AVAILABLE &OR INSTANCE THE 6 VOLTAGE IS ALWAYS ON EVEN IF THE MONITOR HAS BEEN SWITCHED OFF WITH THE SLEEP SWITCH )T IS THUS IMPORTANT TO CUT OFF THE MAINS CURRENT BY REMOVING THE PLUG FROM THE SOCKET WHEN DOING REPAIR JOBS
4HE BLOCK DIAGRAM
4HE MONITORèS POWER SUPPLY AND DEFLECTION PARTS BLOCK DIAGRAM IS REPRESENTED IN PICTURE )T CONTAINS THE FOLLOWING OPERATIONAL BLOCKS
:
0ICTURE
:
4HE POWER SUPPLY
0RODUCES THE VOLTAGES NEEDED BY THE MONITOR #ONTAINS ALSO THE 6%3! 0OWER 3AVE AND PICTURE TUBE DEMAGNETIZING FUNCTIONS 4HE OPERATIONAL FREQUENCY HAS BEEN SYNCHRONIZED TO THE HORIZONTAL DEFLECTION FREQUENCY
4HE POWER SAVE FUNCTION
4HIS FUNCTION LOWERS THE MONITORèS POWER CONSUMPTION IN 6%3! 0OWER 3AVE MODES 4HE FUNCTION IS COMPOSED OF ELECTRONICS AND SOFTWARE
4HE DEFLECTION DRIVER
&ORMS A CORRECTLY TIMED CONTROL SIGNAL COMPARED TO THE INCOMING SYNC PULSE FOR THE HORIZONTAL OUTPUT STAGE #ONTROLS THE VERTICAL OUTPUT STAGE AND FORMS THE VERTICAL FREQUENCY PICTURE GEOMETRY CORRECTING VOLTAGES AND THE VERTICAL FREQUENCY CONTROL VOLTAGE FOR THE DYNAMIC FOCUS "LANKS THE SCREEN DURING MODE CHANGE SITUATIONS #ONTROLS THE HIGH VOLTAGE
4HE WIDTH CONTROL CIRCUIT
&ORMS THE PROPER SUPPLY VOLTAGE FOR THE HORIZONTAL OUTPUT STAGE 3UMS TO THIS VOLTAGE THE REQUIRED GEOMETRY CORRECTING VOLTAGES %7 AND TRAPEZIUM
4HE HIGH VOLTAGE GENERATOR
&ORMS THE REGULATED K6 HIGH VOLTAGE AS WELL AS THE FOCUS
AND '
VOLTAGE 3YNCHRONIZES THE POWER SUPPLY
4HE VERTICAL OUTPUT STAGE
&ORMS A PROPER CURRENT FOR THE VERTICAL DEFLECTION COIL &ORMS THE VERTICAL BLANKING PULSE
4HE HORIZONTAL OUTPUT STAGE
&ORMS THE CURRENT NEEDED BY THE HORIZONTAL DEFLECTION COIL THE $#
CURRENT NEEDED BY THE FRAME CENTERING AND THE LINEARITY AND 3
CORRECTION 4HE LINE FLY
BACK PULSE &"0 FORMED BY THE STAGE IS USED TO THE CONTROLLING OF THE HIGH
VOLTAGE GENERATOR AND THE DEFLECTION COIL AND TO THE FORMING OF THE LINE BLANKING PULSE
4HE BLANKING CIRCUIT
&ORMS THE VERTICAL AND HORIZONTAL BLANKING PULSES BLANKS AND NARROWS THE SCREEN DURING A MODE CHANGE SITUATION
/THER FUNCTIONS
!UXILIARY FUNCTIONS ARE FOR EXAMPLE ! BEAM CURRENT LIMITER CIRCUIT WHICH LIMITS THE MAXIMUM BEAM CURRENT TO THE DESIRED LEVEL ! 4#/
COMPENSATING CIRCUIT WHICH FORMS A 4#/ COMPENSATING PULSE USED TO REDUCE THE ELECTRIC FIELD EMITTED BY THE MONITOR ! RESET
CIRCUIT WHICH FORMS THE RESET PULSE NEEDED BY THE PROCESSOR &ORMS A PULSE ALSO IN A PICTURE TUBE CROSS
OVER SITUATION WHICH DECREASES THE RISK FOR THE PROCESSOR TO FAIL ! CLAMP PULSE FORMING CIRCUIT WHICH FORMS THE BLACK LEVEL CLAMP PULSE NEEDED BY THE VIDEO ! -OIRE
ADJUSTMENT CIRCUIT USED TO MINIMIZE THE -OIRE ON THE PICTURE ! DEMAGNETIZATION CIRCUIT USED TO DEMAGNETIZE THE METAL PARTS OF THE MONITOR
$$#
$ISPLAY $ATA #HANNEL OR $$# IS A TWO
WAY DATA TRANSFER CHANNEL BETWEEN THE MONITOR AND THE COMPUTER )T CAN BE USED FOR EXAMPLE TO TRANSFER INFORMATION ABOUT THE MONITOR FEATURES THE MAXIMUM REFRESHING FREQUENCY SO THAT THE COMPUTER CAN OPTIMIZE THE MONITOR FEATURES AUTOMATICALLY
:
!UDIO STAGE
4HE MONITOR HAS OPTIONAL AUDIO PART WHICH CONTAINS A STEREO AUDIO AMPLIFIER SPEAKERS AN INTERNAL MICROPHONE AND A MICROPHONE AMPLIFIER !DDITIONALLY THERE IS A HEADPHONE PLUG AND AN EXTERNAL MICROPHONE PLUG
4HE MICROPROCESSOR
#ONTROLS THE MONITOR FUNCTIONS ACCORDING TO THE HORIZONTAL AND VERTICAL SYNC PULSES AND THE ORDERS GIVEN BY THE USER
4HE VIDEO AMPLIFIER
!MPLIFIES THE APPROX 6 2'" SIGNALS COMING FROM THE VIDEO CARD THROUGH THE SIGNAL CABLE TO APPROX 6 DRIVE VOLTAGES APPROPRIATE TO THE PICTURE TUBE
4HE POWER SUPPLY
'ENERAL FEATURES
4HE VOLTAGE SUPPLY IS A SECONDARY REGULATED CURRENT MODE CONTINUOUSNON
CONTINUOUS &LY
BACK TYPE SWITCH MODE POWER SUPPLY WITH AN OPERATIONAL VOLTAGE RANGE OF õ 6!# 4HE REGULATION FROM THE SECONDARY HAS BEEN ACHIEVED WITH AN OPTO
ISOLATOR 4HE OPERATIONAL FREQUENCY SWITCH MODE FREQUENCY IS õ K(Z AND IT IS SYNCHRONIZED TO LINE FREQUENCY 4HE POWER SUPPLY OPERATES IN A NON
CONTINUOUS OPERATIONAL MODE USING LOW PRIMARY CURRENTS AND CONVERTS TO CONTINUOUS MODE WHEN THE LOAD INCREASES 4HE VOLTAGE SUPPLY IS BASED ON A 3'3
4HOMSON )#
CIRCUIT , CURRENT MODE 07- 4HE BLOCK DIAGRAM IS SHOWN IN PICTURE
0ICTURE 4HE POWER SUPPLYèS CONTROL CIRCUIT , IS BASED ON THE POPULAR 5# CIRCUIT AND CONTAINS A DIFFERENTIAL AMPLIFIER A 2#
OSCILLATOR A CURRENT MEASURING COMPARATOR A 6 REFERENCE VOLTAGE AN OUTPUT STAGE FOR THE CONTROL OF THE &%4 AND AN UNDER VOLTAGE LOCKOUT )N ADDITION TO THE ABOVE MENTIONED FUNCTIONS OF THE 5# THE CIRCUIT HAS ALSO A PROGRAMMABLE 3OFT START FUNCTION A TWO STAGE OVER CURRENT
:
PROTECTION A LOCKOUT CIRCUIT OF THE PULSE RATIO NOT USED IN THIS MONITOR SINCE THE PULSE RATIO HAS BEEN ADJUSTED TO AND AN OVER VOLTAGE DISABLE FUNCTION 7ITH THESE FUNCTIONS THE POWER SUPPLYèS OPERATION IS MORE RELIABLE IN VARIOUS ERROR SITUATIONS
4HE START
UP
4HE SUPPLY VOLTAGE IS RECTIFIED WITH DIODES $õ$ AND FILTERED WITH CAPACITOR # )# GETS THE CURRENT NEEDED FOR START
UP THROUGH 4 4 2 2 AND 2 7HEN # VOLTAGE RISES TO 6 )#èS UNDER VOLTAGE FUNCTION ALLOWS THE )# START
UP !T THAT TIME THE )# OSCILLATOR STARTS
UP AND &%4 4 GOES LEADING 3IMULTANEOUSLY THE CAPACITOR OF PIN OF THE )# SOFT START STARTS TO CHARGE WITH STANDARD CURRENT OF µ! 4HE CURRENT THROUGH MAINS TRANSFORMER - PRIMARY COIL PINS AND AND THE &%4 STARTS TO GROW UNTIL THE VOLTAGE LOSS OVER CURRENT MEASUREMENT RESISTORS 2 2 RISES TO THE SAME LEVEL AS THE SOFT START CAPACITORS # VOLTAGE IN PIN WHICH IS CLAMPING THE OUTPUT VOLTAGE OF THE INTERNAL CURRENT MEASUREMENT COMPARATOR %! ON THE BLOCK DIAGRAM !T THAT TIME THE CURRENT MEASUREMENT COMPARATOR DIRECTS THE &%4 TO OFF
MODE AND THE ENERGY CHARGED IN THE PRIMARY COIL IS TRANSFERRED TO THE SECONDARY COILS AND FROM THERE ON THROUGH THE SECONDARY DIODES TO THE SECONDARY CAPACITORS !FTER THIS THE )# OSCILLATOR AGAIN DRIVES THE &%4 4 TO CONDUCT AND SO ON 4HE SOFT START CAPACITORS VOLTAGE RISES ALL THE TIME GROWING ALSO THE PULSE RATIO SO THAT IN EVERY PERIOD THE CURRENT THROUGH THE PRIMARY COIL IS HIGHER 4HE PULSE RATIO IS THUS VERY LOW AT THE BEGINNING OF THE START
UP THEREFORE RISING SLOWLY THE VOLTAGES AT THE SECONDARY 7HEN THE SOFT START CAPACITOR HAS BEEN CHARGING TO ITS MAXIMUM THE SOFT START CIRCUIT DOES NOT LIMIT THE FUNCTION OF THE POWER SUPPLY 4HE )# OSCILLATOR DIRECTS THE 4 &%4 TO LEADING AND SO ON 4HIS GOES ON AS LONG AS THE SECONDARY CAPACITORS HAVE BEEN CHARGED TO THE RIGHT VOLTAGE !T THAT TIME THE FEEDBACK STARTS TO CONTROL THE )# DIFFERENTIAL AMPLIFIER WHICH CONTROLS THE PRIMARY CURRENT THROUGH THE &%4 LOOK CURRENT REGULATION 7HEN )# IS OPERATIONAL ITS PIN HAS A 6 VOLTAGE 4HIS VOLTAGE DRIVES THE TRANSISTOR 4 LEADING THROUGH 2 !T THAT TIME THE VOLTAGE IN TRANSISTOR 4 BASE DECREASES UNDER THE SUPPLY VOLTAGE OF )# SO THAT TRANSISTOR 4 GOES NON
CONDUCTING 3IMULTANEOUSLY THE CURRENT THROUGH RESISTORS 2 AND 2 IS REMOVED AND )# GETS ITS SUPPLY VOLTAGE SOLELY THROUGH THE PRIMARYèS AUXILIARY COIL PINS AND AND DIODE $ )F THE )#èS SUPPLY VOLTAGE DROPS UNDER 6 )#èS INTERNAL UNDER VOLTAGE LOCKOUT CIRCUIT SWITCHES OFF THE )# AND THUS ALSO THE POWER SUPPLY SO THAT THE START
UP SEQUENCE STARTS FROM THE BEGINNING
4HE SYNCHRONIZING
4HE POWER SUPPLY IS SYNCHRONIZED TO HORIZONTAL DEFLECTION FREQUENCY 4HE POSITIVE LINE FLY
BACK PULSE &,9"!#+?4/?0,, COMING FROM THE HORIZONTAL DEFLECTION OUTPUT STAGE IS DIRECTED WITH 2 AND $ THROUGH THE OPTO
ISOLATOR )# TO THE SYNCHRONIZING PIN OF )# # IS USED TO ACCELERATE THE SYNCHRONIZING SMALLER DELAY AND THE PULSE IS OPTIMIZED FOR THE OPTO
ISOLATOR WITH 2 AND 2 4HE RISING PULSE EDGE GOING OVER 2 IS TRIGGERING THE )# OSCILLATOR THUS DIRECTING &%4 4 TO LEADING 4HE FREE OSCILLATION FREQUENCY OF THE POWER SUPPLYèS OSCILLATOR IS CONTROLLED WITH COMPONENTS # AND 2 WHICH CONTROL THE POWER SUPPLYèS FREE OSCILLATION FREQUENCY WHEN THE DEFLECTION STAGE IS NOT RUNNING FOR INSTANCE A POWER
OFF SITUATION 4HIS FREE OSCILLATION FREQUENCY IS APPROX K(Z
4HE VOLTAGE REGULATION
4HE VOLTAGE FEED
BACK INFORMATION IS TAKEN FROM THE 6 VOLTAGE WHICH IS DROPPED TO THE REFERENCE VOLTAGE LEVEL 6 OF REGULATOR 4 WITH RESISTORS 2 AND 2 2EGULATOR 4 IS COMPOSED OF AN INVERTING AMPLIFIER AND A REFERENCE VOLTAGE &UNCTION DESCRIPTION THROUGH AN EXAMPLE )F THE 6 VOLTAGE IS INCREASING THE CHARGE LOAD DECREASES THE 4 GRID VOLTAGE INCREASES 4HEN THE CURRENT THROUGH 4 AND 2 INCREASES AS WELL 4HIS CURRENT INCREASES THE VOLTAGE LOSS OF RESISTOR 2 AT WHICH TIME THE )# OPTO ISOLATOR DIODE CURRENT DECREASES 4HIS DRIVES THE CURRENT OF TRANSISTOR )# AND RESISTOR 2 TO DECREASE WHICH MAKES THE VOLTAGE OF )# PIN OPTO ISOLATORS NEGATIVE INPUT TO RISE AND THE OUTPUT VOLTAGE OF THE OPTO ISOLATOR TO DROP 4HE OUTPUT VOLTAGE OF THE OPTO ISOLATOR FUNCTIONS AS THE REFERENCE VOLTAGE OF THE CURRENT MEASUREMENT COMPARATOR AT WHICH TIME THE COMPARATOR DECREASES THE PRIMARY CURRENT THUS DECREASING AS WELL THE 6 SECONDARY VOLTAGE 4HE FAST CURRENT CHANGES ARE SUMMED TO THE FEED
BACK WITH CAPACITOR # AND THE POWER SUPPLY IS REACTING MORE RAPIDLY TO THE CHARGE CHANGES
:
3LOPE COMPENSATING
4HE PRIMARY CURRENT PULSE RATIO CANNOT EXCEED SO THE )# SWITCHING CONTAINS SLOPE COMPENSATING SO THAT THE STABILITY OF THE POWER SUPPLY WOULD BE SECURED IN ALL SITUATIONS 4HE SAW
TOOTH WAVE OF )# OSCILLATOR FROM # IS SUMMED TO THE INPUT VOLTAGE OF THE CURRENT MEASUREMENT COMPARATOR )# PIN WITH 4 2 # 2 AND #
4HE OVER CURRENT CONTROL
4HE CIRCUIT , CONTAINS AN OVER CURRENT CONTROL CIRCUIT WHICH PREVENTS THE SECONDARY VOLTAGES TO RISE TOO HIGH IN A FAILURE SITUATION THUS PREVENTING THE ELECTROLYTE CAPACITORS FROM BEING DAMAGED )N THIS PARTICULAR SITUATION THEY WOULD CAUSE AN ABUNDANT QUANTITY OF SMOKE WHICH IS NOT ACCEPTABLE EVEN IN A FAILURE SITUATION )N A NORMAL SITUATION WHEN THE 6 VOLTAGE IS AT THE RIGHT LEVEL THE )# SUPPLY VOLTAGE IS APPROX 6 PIN !T THAT TIME THE )# PIN $)3 VOLTAGE IS APPROX 6 WITH THE HELP OF RESISTORS 2 AND 2 )F THE DEVICE FAILS IN SUCH A WAY THAT THE REGULATION DOES NOT WORK AND SECONDARY VOLTAGES RISE TOO HIGH OVER 6 THE )# PIN VOLTAGE INCREASES AS WELL 7HEN ITS VOLTAGE INCREASES TO 6 PIN OF THE )# &%4 CONTROL GOES DOWN IMMEDIATELY AND THE )# OSCILLATOR SHUTS DOWN !T THAT POINT THE POWER SUPPLY OF THE MONITOR IS COMPLETELY SHUT DOWN AND THE SECONDARY VOLTAGES DECREASE AND WILL NOT RISE TOO HIGH EVEN FOR A MOMENT )N THIS SITUATION THE CIRCUITèS REFERENCE VOLTAGE 6 ON PIN GOES DOWN SO THAT 4 IS SATURATED AND ITS COLLECTOR VOLTAGE GOES UP !FTER THIS 4 AND GO LEADING AND FEED CURRENT TO )# )TS VOLTAGE ON PIN INCREASES TO APPROX 6 BECAUSE A ZENER
DIODE INSIDE THE CIRCUIT LIMITS THE VOLTAGES TO THAT PARTICULAR FACTOR 4HE )# WILL NOT RESTART IN AN OVER CURRENT SITUATION UNTIL ITS SUPPLY VOLTAGE HAS DECREASED UNDER 6 AND ON THE OTHER HAND 4 AND CONTINUE TO FEED CURRENT TO THE CIRCUIT VOLTAGE IS MAINTAINED AT 6 THE SITUATION IS LATCHED THE POWER SUPPLY WILL NOT START WITHOUT A SEPARATE ACTION 4HIS SITUATION IS EASILY NOTICEABLE SINCE THE ,%$ IS NOT LIT NO VOLTAGES IN THE SECONDARY AND THE )# SUPPLY VOLTAGE IS APPROX 6 4HIS SITUATION CAN BE DISCONTINUED ONLY BY SWITCHING OFF THE SUPPLY POWER FOR ABOUT MINUTES AT WHICH TIME THE # AND # VOLTAGES IS DISCHARGED 4HE MEMBRANE KEY ON THE FRONT PANEL OF THE MONITOR IS NOT OPERATING BUT THE ONLY WAY IS TO UNPLUG THE MAINS CORD 4HIS IS NOT A PROBLEM IN PRACTICE SINCE THIS OVER CURRENT SITUATION IS A SIGN OF A SERIOUS FAILURE SO THE MONITOR HAS TO BE REPAIRED ANYWAY # OPERATES AS A FILTERING CAPACITOR THUS PREVENTING EFFECTS OF EXTERNAL DISTURBANCES TO THE CIRCUIT
4HE PRIMARY CURRENT LOCKOUT
4HE CIRCUIT HAS A TWO STAGE PRIMARY CURRENT MEASUREMENT AND PROTECTION FUNCTION 7HEN THE POWER SUPPLY IS FUNCTIONING NORMALLY THE MAXIMUM PULSE VOLTAGE OF 2 AND IS APPROX 6 THE FEED
BACK INFORMATION COMING FROM THE SECONDARY DIRECTS THE PULSE RATIO OF THE PRIMARY SWITCH WITH THE CURRENT MEASUREMENT COMPARATOR AND THUS ALSO THE SECONDARY VOLTAGES 4HE VOLTAGE REGULATION OPERATES AS MENTIONED BEFORE )F AN OVER CURRENT SITUATION OCCURS AND THE PRIMARY CURRENT HAS TIME TO RISE TO A LEVEL WHERE THE CURRENT MEASUREMENT RESISTORS 2 AND VOLTAGE IS OVER 6 THE CIRCUITS OVER CURRENT PROTECTION FUNCTION STARTS UP !T THAT TIME THE CIRCUIT CUTS OFF IMMEDIATELY THE CONTROL OF THE PRIMARY SWITCH THE CIRCUITS PIN GOES DOWN AT ONCE AND DISCHARGES THE SOFT START CAPACITOR AT PIN # !T THAT TIME THE CIRCUIT STARTS THE NEXT PERIOD WITH A VERY SHORT CONTROL PULSE AND IF THE OVER CURRENT SITUATION IS STILL ON 2 AND VOLTAGE STILL OVER 6 THAT IS PLENTY OF PRIMARY CURRENT THE # VOLTAGE MUST RISE TO 6 BEFORE IT IS DISCHARGED AND THE PRIMARY SWITCH IS KEPT NON
LEADING ALL THIS TIME THE POWER SUPPLY IS SHUTDOWN AND THERE IS NO PRIMARY CURRENT )N AN OVER CURRENT SITUATION LIKE THIS FOR EXAMPLE A COMPONENT OF THE SECONDARY SIDE IN SHORT
CIRCUIT THE CIRCUIT GIVES CURRENT TO THE SECONDARY FOR A VERY BRIEF MOMENT AND IS SHUT DOWN MOST OF THE TIME SO THERE IS NOT MUCH POWER GOING TO THE SECONDARY 4HIS WAY THE OVER CURRENT COMPONENTSè TEMPERATURE DOES NOT RISE TOO HIGH AND ADDITIONAL DAMAGES AND SMOKE ARE AVOIDED )F THE OVER CURRENT SITUATION IS ONLY TEMPORARY FOR EXAMPLE AN ERROR IN A MODE CHANGE SITUATION THE MONITOR IS OPERATING NORMALLY WITHOUT THAT THE USER EVEN NOTICES ANY ABNORMALITY
:
4HE SECONDARY CURRENT LOCKOUT
4HE 6 AND 6 SECONDARY COILS ARE SERIAL CONNECTED SO THAT THE CURRENT OF BOTH VOLTAGES GOES THROUGH 2 AND )N AN OVER CURRENT SITUATION THE VOLTAGE LOSS OF THESE RESISTORS INCREASES HIGHER THAN 6 AT WHICH TIME 4 GOES LEADING AND GIVES EXTRA CURRENT TO THE FEED
BACK INFORMATION WITH 2 !T THAT TIME THE VOLTAGE OF REGULATOR 4 GRID INCREASES AND WITH FEED BACK INFORMATION THE POWER SUPPLYèS OUTPUT VOLTAGES DECREASE AS WELL &OLLOWING THIS ALSO THE VOLTAGE OF THE PRIMARYèS AUXILIARY COIL PINS AND DECREASE AT WHICH TIME THE SUPPLY POWER OF )# DECREASES UNDER 6 !T THAT TIME THE UNDER CURRENT LOCKOUT OF THE )# PREVENTS THE )# AND THE POWER SUPPLY FROM OPERATING 4HE POWER SUPPLY TENDS TO RESTART ITSELF AFTER A MOMENT AND IF THE OVER CURRENT SITUATION IS STILL THERE THE LOCKOUT FUNCTION OF THE SECONDARY CURRENT IS REPEATED 4HE SMALLER SECONDARY VOLTAGES ARE PROTECTED FROM OVER CURRENT WITH INFLAMMABLE RESISTORS OR FUSES WHICH BURN AND CUT IN AN OVER
CURRENT SITUATION
4HE 56,/ SIGNAL
4HE 56,/ SIGNAL TRANSISTOR 4 IS USED TO STABILIZE THE FUNCTIONING OF THE FIELD DEFLECTION AND THE HIGH
VOLTAGE GENERATOR IN START AND SHUTDOWN SITUATIONS OF THE MONITOR 4HE 56,/ SIGNAL IS ACTIVATED WHEN THE 0OWER SWITCH IS PRESSED OR IF THE 6/&& VOLTAGE DROPS UNDER 6 FOR INSTANCE WHEN IN A SUPPLY POWER FAILURE OR WHEN THE DEVICE GOES TO 0OWER /FF
MODE 7HEN THE 6/&& VOLTAGE IS UNDER 6 THE VOLTAGE IN 4 BASE IS UNDER 6 SO IT IS NOT LEADING 4HE 4 COLLECTOR AND 4 BASE IS THEREFORE UP SO 4 IS LEADING AND DECREASING THE 56,/ SIGNAL 7HEN THE 6/&& VOLTAGE RISES AND EXCEEDS 6 4 GOES LEADING AND 4 NON
LEADING SO THE 56,/ SIGNAL GOES UP 7HEN THE 56,/ SIGNAL GOES DOWN DUE TO FOR EXAMPLE A POWER FAILURE IT RESETS THE WIDTH MODULATOR )# THROUGH DIODE $ BY PULLING )# PIN DOWN !T THAT TIME THE POWER FEED TO THE LINE DEFLECTION DRIVER IS CUT OFF 3IMULTANEOUSLY CAPACITOR # IS DISCHARGED AND THE IMAGE WIDTH ADJUSTS TO MINIMUM $EFLECTION DRIVER )# GETS STILL SUPPLY POWER 6 IS DROPPING BUT IS STILL HIGH ENOUGH FOR THE FUNCTIONING OF THE DRIVER AND GIVES (
DRIVE SIGNAL TO THE LINE DEFLECTION OUTPUT STAGES TRANSISTOR 4 4HIS GOES ON UNTIL THE 6 VOLTAGE HAS DROPPED UNDER 6 AT WHICH TIME )# SHUTS DOWN $URING THIS TIME THE TRANSISTOR 4 OF THE LINE DEFLECTION OUTPUT STAGE DISCHARGES THE 3
CAPACITORS 4HIS WAY IT IS BEING MADE SURE THAT IN THE NEXT START UP THE LINE DEFLECTION STAGE DOES NOT START UP WITH A TOO HIGH SUPPLY POWER 3
CAPACITOR VOLTAGE 7HEN THE 56,/ SIGNAL GOES DOWN THE 4 BASE GOES TO APPROX 6 WITH $ &OLLOWING THIS THE 4 GRID CANNOT RISE OVER 6 SO IT DOES NOT GO LEADING AND THE HIGH VOLTAGE GENERATOR SHUTS DOWN 4HIS WAY THE PROPER FUNCTIONING OF THE HIGH VOLTAGE GENERATOR DURING POWER FAILURES IS SECURED 4HE 56,/ SIGNAL IS ALSO SUMMED TO THE BLANK SIGNAL 6?",!.+ WITH DIODE $ THUS PREVENTING THE APPEARING OF A FUZZY IMAGE NOT SYNCHRONIZED AND SO ON IN START AND SHUTDOWN SITUATIONS !DDITIONALLY THE 56,/ SIGNAL IS SWITCHED WITH $ TO THE $%-! DEMAGNETIZING FUNCTION 7HEN PROCESSOR )# GOES TO A START UP SITUATION WHEN 6 IS TOO LOW IT RISES ITS START PIN AND THIS WOULD START THE DEMAGNETIZATION ALSO IN SHUTDOWN SITUATIONS WHICH IS NOT DESIRED 4HIS FAILURE SITUATION IS PREVENTED WITH $
4HE POWER SAVE FUNCTION
'ENERAL
4HE POWER SUPPLY CONTAINS THE SWITCHES WHICH ARE USED BY THE PROCESSOR TO CONTROL THE VARIOUS POWER SAVE MODES OF THE MONITOR )N PRACTICE THIS MEANS THAT THE SUPPLY VOLTAGES OF CERTAIN BLOCKS OF THE MONITOR ARE CUT OFF AT WHICH TIME THE MONITOR POWER CONSUMPTION IS DECREASING !DDITIONALLY THE VIDEO AMPLIFIER IS DIRECTED VIA BRIGHTNESS AND CONTRAST LINES TO A MODE WHERE POWER CONSUMPTION IS THE LOWEST 4HE SWITCHING FOR THE DISABLING OF )#èS START UP CURRENT IS ALSO PART OF THE POWER SAVE FUNCTION 4HE PROCESSOR MONITORS THE INCOMING SYNC PULSES AND DIRECTS THE MONITOR THROUGH 6%3! 0OWER 3AVE -ANAGEMENT 3TANDARD AS FOLLOWS
:
/N
MODE
)F BOTH LINE AND FIELD PULSES ARE BROUGHT TO THE MONITOR THE PROCESSOR INTERPRETS IT AS /.
MODE 4HIS MODE CORRESPONDS TO NORMAL USE
3TAND BY
MODE
)F LINE SYNC PULSES ARE MISSING THE PROCESSOR INTERPRETS IT AS 3TAND
BY MODE !T THAT TIME THE PROCESSOR DECREASES THE BRIGHTNESS AND CONTRAST LINE AND THE MONITOR IMAGE IS BLACK 3IMULTANEOUSLY THE PROCESSOR STARTS UP AN INTERNAL SYNC PULSE GENERATING AND THE LINE DEFLECTION FREQUENCY IS AT K(Z 4HE POWER SAVE IS SMALL COMPARED TO THE NORMAL MODE
3USPEND
MODE
)F FIELD SYNC PULSES ARE MISSING THE PROCESSOR INTERPRETS IT AS 3USPEND
MODE )N 3USPEND
MODE THE PROCESSOR PULLS DOWN THE 7'%.?).()")4 LINE )# PIN 7HEN THIS SIGNAL IS DOWN $ PULLS DOWN )# PIN WITH $ AT WHICH TIME THE WIDTH MODULATOR GOES TO STATIC CLEAR
MODE AND DOES NOT GIVE ANY CONTROL PULSES TO THE WIDTH SWITCH MODE "ECAUSE THE WIDTH SWITCH MODE IS NOT FUNCTIONING THE LINE OUTPUT STAGE DOES NOT GET ANY SUPPLY VOLTAGE AND IS THEREBY GOING OFF AND CUTTING OFF THE HIGH VOLTAGE GENERATOR 4HE SUPPLY VOLTAGES OF THE FIELD OUTPUT STAGE ARE NOT CUT OFF IN THIS MODE 6 IS NOT CUT OFF EITHER SO THE FIELD OSCILLATOR AND LINE OSCILLATOR ARE STILL RUNNING JUST LIKE AT /.
MODE 4HE FILAMENT CURRENT CAN FLOW NORMALLY SO THE RETURN FROM THIS MODE TO /.
MODE IS RAPID THE IMAGE COMES BACK IN APPROX SECOND )N SUSPEND
MODE THE POWER SAVE IS QUITE IMPORTANT THE CONSUMPTION BEING APPROX 7
0OWER OFF MODE
)F BOTH SYNC PULSES ARE MISSING THE PROCESSOR INTERPRETS THIS AS 0OWER OFF
MODE )N POWER OFF
MODE THE PROCESSOR PULLS UP THE /&& LINE )# PIN 7HEN THIS LINE IS UP 4 IS LEADING AND ITS COLLECTOR PULLS DOWN THE 4 GRID 4 GOES NON
LEADING AND THE 6/&&
VOLTAGE FROM THE FIELD OUTPUT STAGE IS CUT OFF 4 GOES ALSO NON
LEADING WITH ZENER DIODE $: BECAUSE ITS GRID VOLTAGE WHICH NORMALLY IS APPROX 6 SOURCE IS AT
6 SO THE SOURCE
GRID VOLTAGE IS APPROX 6 DROPS TO APPROX
6 "ECAUSE THE &%4 SOURCE IS ALSO AT
6 THE SOURCE
GRID CONTROL VOLTAGE IS 6 AT WHICH TIME THE
6 FROM THE FIELD OUTPUT STAGE IS CUT OFF !T THIS TIME THE FIELD OUTPUT STAGE DOES NOT CONSUME ANY POWER "ECAUSE 6/&& IS CUT OFF THE 6 OUTPUT VOLTAGE OF REGULATOR )# IS ALSO CUT OFF $UE TO THIS ALL 6 CIRCUITS AMONG OTHERS )# ARE INACTIVE AND DO NOT CONSUME ANY POWER "ECAUSE THE FILAMENT REGULATOR )#èS INPUT VOLTAGE 6/&& IS CUT OFF THE FILAMENT VOLTAGE IS ALSO CUT OFF !T THIS POINT THE MONITORèS POWER CONSUMPTION IS TYPICALLY APPROX 7
4HE DEFLECTION DRIVER
'ENERAL
4HE USED DEFLECTION DRIVER IS A 3'3
4HOMSON CIRCUIT 4$! 4HIS CIRCUIT CONTAINS STAGES TO CONTROL BOTH THE LINE DEFLECTION AND THE FIELD DEFLECTION !DDITIONALLY THERE IS BASIC PICTURE GEOMETRY ADJUSTING FUNCTIONS /THER FUNCTIONS ARE THE X
RAY LOCKOUT CIRCUIT THE UNDER VOLTAGE LOCKOUT THE BLANKING OUTPUT AND THE FIELD FREQUENCY PARABOLA FOR THE CONTROL OF THE FOCUS 4HE OPERATIONAL FREQUENCY RANGE OF THE CIRCUIT IS
K(Z AND THE SUPPLY VOLTAGE RANGE
6 4HE CIRCUIT IS PACKAGED IN A
PIN $)0 BOX
:
"LOCK DIAGRAM
4HE 4$! BLOCK DIAGRAM IS REPRESENTED IN PICTURE
0ICTURE 4WO SEPARATE FIELDS CAN BE OBSERVED IN THE BLOCK DIAGRAM LINE FREQUENCY AND FIELD FREQUENCY BLOCKS ,INE FREQUENCY BLOCKS FORM AN ë(
DRIVEì SIGNAL TO THE LINE DEFLECTION OUTPUT STAGE AND THE FIELD FREQUENCY BLOCKS FORM A CONTROL VOLTAGE TO THE VERTICAL DEFLECTION OUTPUT STAGE !DDITIONALLY THE FIELD FREQUENCY BLOCKS FORM THE PICTURE GEOMETRY ADJUSTING VOLTAGES 4HE CIRCUIT HAS ALSO COMMON BLOCKS FOR THE LINE AND FIELD FREQUENCY PARTS LIKE THE BLANKING BLOCK AND THE SAFETY FUNCTION BLOCK ëSAFETY PROCESSORì
4HE LINE FREQUENCY BLOCKS
4HE LINE FREQUENCY BLOCKS FORM TWO STAGE LOCKS AFTER ANOTHER 0,, AND 0,, 0,, IS COMPOSED OF THE PHASEFREQUENCY COMPARATOR AND THE 6#/ 4HE COMPARATOR KEEPS THE 6#/ FREQUENCY AT THE SAME LEVEL AS THE INCOMING SYNC PULSES FREQUENCY 4HE SAW TOOTH WAVE FORMED BY THE 6#/ MEASURED FROM PIN IS PHASE ADJUSTABLE AGAINST THE INCOMING SYNC PULSES PIN WITH A $#
VOLTAGE BROUGHT FROM PIN 4HE CIRCUIT HAS BEEN ADJUSTED IN SUCH A WAY THAT WHEN THE CONTROL VOLTAGE IS AT THE MID POSITION 6 THE MIDDLE OF THE FLY
BACK PULSE IS FROM THE PHASE TIME BEHIND THE TRAILING EDGE OF THE SYNC PULSE 4HE WHOLE ADJUSTING RANGE õ6 IN PIN IS
4HE 0,, PHASE COMPARATOR FUNCTION CAN BE PREVENTED WITH A POSITIVE VOLTAGE BROUGHT TO PIN !T THAT TIME THE 6#/ VOLTAGE IS NOT DEPENDENT ON THE INCOMING SYNC PULSES 4HIS METHOD CAN BE USED IN A SITUATION WHERE THE INFLUENCE OF NON DESIRED SYNC PULSES TO THE DEFLECTION FREQUENCY HAS TO BE PREVENTED WHEN USING A COMPOSITE SYNC PULSE FOR INSTANCE 0,, CONTAINS ALSO A DETECTOR WHICH INDICATES WHETHER THE PHASE LOCK IS LOCKED OR NOT TO THE INCOMING SYNC PULSE )F THE PHASE LOCK IS LOCKED THE VOLTAGE IN PIN (
LOCK CAP IS HIGH EXCEEDS 6 AND THE INTERNAL TRANSISTOR OPEN COLLECTOR IN PIN IS NON
LEADING THAT IS PIN IS UP )F THE PHASE LOCK IS NOT LOCKED THE VOLTAGE IN PIN DROPS UNDER 6 AND THE TRANSISTOR IN PIN IS LEADING SO PIN IS DOWN
:
0,, COMPARES THE PHASE OF THE INCOMING LINE FLY
BACK PULSE TO PIN AND THE 6#/ )F THE PHASE OF THE LINE FLY
BACK PULSES IS CHANGING COMPARED TO THE 6#/ PHASE FOR EXAMPLE FOR THE HEAT DRIFTING OF THE DEFLECTION TRANSISTOR THE OUTPUT VOLTAGE OF THE COMPARATOR IN PIN IS CHANGING WHICH IN TURN CHANGES THE RESOLVING LEVELS OF THE INTERNAL COMPARATORS AND THROUGH THAT THE PHASE OF THE (?$RIVE SIGNAL THEREBY READJUSTING THE FLY
BACK PULSES PHASE TO THE RIGHT LEVEL 0HASE LOCK IS THEREBY COMPENSATING THE VARIOUS DELAYS EMERGING FROM THE DEFLECTION OUTPUT STAGE 4HE (?$RIVE SIGNAL IS BROUGHT OUT EITHER FROM PIN OR PIN 0IN IS THE EMITTER OF THE OUTPUT TRANSISTOR AND PIN IS A COLLECTOR 4HE (
DRIVE SIGNAL PULSE RATIO CAN BE ADJUSTED BY CHANGING THE $#
VOLTAGE OF PIN 4HE ADJUSTING RANGE IS õ
4HE FIELD FREQUENCY BLOCKS
4HE CIRCUITèS VERTICAL PART CONTAINS A VERTICAL OSCILLATOR WHICH IS SYNCHRONIZED WITH VERTICAL SYNC PULSES PIN )T FORMS A RAMP VOLTAGE WHICH IS USED TO CONTROL THE VERTICAL OUTPUT STAGE 4HIS SAME RAMP VOLTAGE IS USED TO FORM THE ADJUSTING SIGNALS FOR THE IMAGE GEOMETRY USING MULTIPLIERS AND SUM CIRCUITS 7HEN FORMING THE RAMP VOLTAGE THE CIRCUITS EXTERNAL COMPONENTS ARE THE INTEGRATING CAPACITOR AT PIN AND LEVEL ADJUSTING CAPACITOR AT PIN 4HIS CAPACITOR IS USED TO KEEP THE RAMP AMPLITUDE CONSTANT WHATEVER THE FREQUENCY IS 4HE RAMP IS EXTRACTED FROM PIN 4HE RAMP AMPLITUDE CAN BE ADJUSTED WITH THE ATTENUATOR WHOSE ATTENUATION IS ADJUSTED THROUGH THE $#
VOLTAGE AT PIN 4HE VERTICAL RAMP 3
CORRECTION AND #
CORRECTION CAN BE ADJUSTED WITH THE $#
VOLTAGE OF PINS AND )F THE RAMP WOULD BE COMPLETELY LINEAR THE CENTER OF THE PICTURE WOULD BE SQUEEZED COMPARED TO THE PICTUREèS UPPER AND LOWER EDGE "Y ADDING 3
CORRECTION TO THE RAMP THE IMAGE BECOMES LINEAR !DDITIONALLY IN SOME VERTICAL OUTPUT STAGES A LINEARITY ERROR CAN ARISE AT WHICH TIME THE PICTUREèS UPPER HALF IS NOT EQUAL COMPARED TO THE LOWER HALF 4HIS ERROR CAN BE CORRECTED WITH #
CORRECTION !LSO THE GEOMETRY CORRECTION SIGNALS ARE FORMED FROM THE RAMP SIGNAL OF THE RAMP GENERATOR 4HE %7 PARABOLA IS FORMED FROM THE VERTICAL RAMP WITH THE ANALOGY MULTIPLIER AND THE ATTENUATOR 4HE VERTICAL RAMP IS BROUGHT TO PIN %7 /54 THROUGH THE MULTIPLIER AND THE ADDER 4HE ATTENUATION OF THE ATTENUATOR CAN BE ADJUSTED $#
VOLTAGE AT PIN SO THAT WHEN THE ADJUSTING VOLTAGE IS 6 THE ATTENUATION IS HIGH AND THE PARABOLA AMPLITUDE CLOSE TO ZERO %QUALLY IF THE ADJUSTING VOLTAGE IS 6 THE ATTENUATION IS LOW AND THE PARABOLA AMPLITUDE APPROX 6 4HE TRAPEZIUM CORRECTION VOLTAGE IS FORMED FROM THE VERTICAL RAMP WITH THE ATTENUATOR 4HE ATTENUATORèS ATTENUATION CAN BE ADJUSTED WITH PIN $#
VOLTAGE SO THAT WHEN THE ADJUSTING VOLTAGE IS 6 THE ATTENUATORèS ATTENUATION IS HIGH AND THE OUTPUT VOLTAGE ZERO 7HEN THE ADJUSTING VOLTAGE IS 6 THE ATTENUATION IS LOW AND THE OUTPUT VOLTAGE HIGH )F THE ADJUSTING VOLTAGE IS 6 THE ATTENUATION IS ALSO LOW BUT THE OUTPUT SIGNAL POLARITY HAS BEEN INVERTED TO NEGATIVE SO THAT THE RAMP COMING FROM THE ATTENUATOR IS THE INVERTED COMPARED TO THE IN GOING RAMP !FTER THE ATTENUATOR THE CORRECTION SIGNAL IS DIRECTED THROUGH THE ADDER TO PIN 4HE SUM SIGNAL OF THE PARABOLA AND THE RAMP WHICH IS USED TO MODULATE THE IMAGE WIDTH IS THEREBY OBTAINED FROM PIN 4HE ORTHOGONAL CORRECTION VOLTAGE IS MADE WITH THE SAME PRINCIPLE AS THE TRAPEZIUM CORRECTION VOLTAGE )TS AMPLITUDE IS ADJUSTABLE WITH THE PIN $#
VOLTAGE 4HE SIGNAL IS DIRECTED TO PIN THROUGH THE ADDER 4HE %7 BALANCE CORRECTION VOLTAGE IS FORMED FROM THE VERTICAL RAMP WITH THE MULTIPLIER AND THE ATTENUATOR 4HE MULTIPLIER TRANSFORMS THE RAMP TO A PARABOLA WHICH IS THEN BROUGHT TO PIN THROUGH THE ATTENUATOR AND THE ADDER 4HE ATTENUATORèS ATTENUATION CAN BE ADJUSTED WITH THE $#
VOLTAGE OF PIN 4HE SUM OF TRAPEZIUM CORRECTION VOLTAGE AND %7 BALANCE CORRECTION VOLTAGE IS THEREBY OBTAINED FROM PIN AND IS USED TO MODULATE THE LINE DEFLECTION PHASE 4HE CONTROL PARABOLA FOR THE VERTICAL DYNAMIC FOCUS IS OBTAINED FROM THE %7 PARABOLA WHICH IS SWITCHED TO PIN 4HE DYNAMIC FOCUS AMPLITUDE IS NOT $# ADJUSTABLE BUT ONLY THE IMAGE HEIGHT THE AMPLITUDE OF THE VERTICAL RAMP TRANSFORMS THE AMPLITUDE OF THE DYNAMIC FOCUS 4HE ANALOGY MULTIPLIER CONTAINS ALSO A $#
VOLTAGE INPUT PIN "Y CHANGING THE VOLTAGE OF THIS PIN õ6 AN ASYMMETRY TO THE GEOMETRY CORRECTION SIGNALS IS OBTAINED COMPARED TO THE VERTICAL SWEEP )F THE PIN IS CONNECTED TO THE SAME VOLTAGE WHICH AFFECTS THE VERTICAL FRAMING THE VERTICAL LINES OF THE IMAGE CAN BE FORCED TO REMAIN VERTICAL WHEN SHIFTING THE IMAGE IN VERTICAL
:
4HE PROTECTION FUNCTIONS
0ROTECTION FUNCTIONS HAVE BEEN ADDED TO THE CIRCUIT IN ORDER TO ENSURE THE STABLE FUNCTION OF THE EXTERNAL CONNECTIONS AND THE PROTECTION OF THE PICTURE TUBE 4HESE FUNCTIONS ARE
4HE CUTTING OFF OF THE LINE DEFLECTION OUTPUT STAGES CONTROL SIGNAL ( /54054 ).()")4!4)/.
)S ACTIVATED · · · · )F THE SUPPLY VOLTAGE IS UNDER THE INTERNAL REFERENCE OF 6 )F THE 82!9 PIN VOLTAGE IS EXCEEDS 6 )F THE (
DUTY PIN VOLTAGE IS UNDER 6 $URING THE FLY
BACK PULSE 4HIS IS USED TO PREVENT THE LINE DEFLECTION OUTPUT STAGE TRANSISTOR FROM GOING LEADING DURING THE FLY
BACK PULSE
4HE CUTTING OFF OF THE CONTROL SIGNAL 6 /54054 ).()")4!4)/. )S ACTIVATED IF · 4HE SUPPLY VOLTAGE IS UNDER THE INTERNAL REFERENCE OF 6 · 4HE (
DUTY PIN VOLTAGE IS UNDER 6 4HE BLANKING COMPOSITE BLANKING )S ACTIVATED IF · · · · · · 4HE SUPPLY VOLTAGE IS UNDER THE INTERNAL REFERENCE OF 6 4HE 82!9 PIN VOLTAGE IS OVER 6 4HE (
DUTY PIN VOLTAGE IS UNDER 6 $URING THE LINE FLY
BACK PULSE $URING THE VERTICAL FLY
BACK PULSE $URING THE FIELD SYNC PULSE
&UNCTION IN PRACTICAL SWITCHING
4HE SUPPLY VOLTAGE
4HE CIRCUIT 6 SUPPLY VOLTAGE IS BROUGHT TO PIN 2 AND # # FUNCTION AS FILTERING COMPONENTS 4HE CIRCUIT FORMS REFERENCE VOLTAGES 6REF AND (REF WHICH HAVE THEIR OWN FILTERING CAPACITORS # # AND # # 4HE VALUE OF THESE VOLTAGES IS APPROX 6 4HE GROUND OF THE CIRCUIT IS PIN !DDITIONALLY THE CIRCUIT HAS GROUNDS (GND FOR THE GROUNDING OF THE HORIZONTAL BLOCK AND 6GND FOR THE GROUNDING OF THE VERTICAL BLOCK
4HE SYNCHRONIZING
6ERTICAL SYNC PULSES ARE BROUGHT FROM THE PROCESSORS )# PIN TO PIN OF THE DEFLECTION DRIVER CIRCUIT %VEN IF THE CIRCUIT IS OPERATIONAL AND NOT DEPENDENT ON THE SYNC PULSE POLARITY THE POLARITY IS MADE CONSTANT POSITIVE IN THE PROCESSOR 4HE VALUE OF # ALONE DEFINES THE FREQUENCY RANGE OF THE VERTICAL OSCILLATOR )N THIS MONITOR # HAS BEEN ADJUSTED SO THAT THE CIRCUIT SYNCHRONIZES ITSELF AUTOMATICALLY TO THE WHOLE FREQUENCY RANGE OF THE MONITOR õ(Z )F THERE ARE NO SYNC PULSES THE VERTICAL DEFLECTION TRANSFERS TO FREE OSCILLATION FREQUENCY WHICH IS APPROX (Z 4HE HORIZONTAL SYNC PULSES ARE BROUGHT TO FROM THE PROCESSORèS PIN TO PIN 4HE POLARITY OF THE HORIZONTAL SYNC PULSES IS ALSO MADE CONSTANT POSITIVE IN THE PROCESSOR 4HE 6#/ OF THE CIRCUIT HAS BEEN MEASURED IN SUCH A WAY THAT THE CIRCUIT SYNCHRONIZES ITSELF AUTOMATICALLY TO THE WHOLE FREQUENCY RANGE OF THE MONITOR õ K(Z # AND 2 2 TOGETHER DEFINE THE 6#/ FREQUENCY 7ITH COMPONENT VALUES OF THE SWITCHING THE FREE OSCILLATION FREQUENCY OF THE 6#/ IS APPROX K(Z AND THE MAXIMUM
:
FREQUENCY APPROX K(Z )F THERE ARE NO SYNC PULSES THE HORIZONTAL DEFLECTION SHIFTS TO THE FREE OSCILLATION FREQUENCY # AND # ARE FILTERING COMPONENTS OF 6#/èS INTERNAL CIRCUITS 4HE FREQUENCYèS FEED
BACK IS BROUGHT FROM THE HORIZONTAL DEFLECTION OUTPUT TO PIN WITH RESISTOR 2 0IN IS THE CURRENT INPUT SO THAT THE PIN HAS A TRANSISTOR BASE WHICH HAS A PROTECTION RESISTOR SO THAT THE MAXIMUM PULSE AT THE PIN IS ONLY APPROX 6PP /NE SHOULD TAKE IN ACCOUNT THAT THE CIRCUIT CANNOT FUNCTION ALONE WITH A COMPOSITE SYNC BECAUSE THE CIRCUIT DOES NOT CONTAIN A SEPARATOR CIRCUIT FOR THE FIELD SYNC PULSES AND THE PHASEFREQUENCY COMPARATOR IN THE CIRCUIT IS SENSITIVE TO POSSIBLE ADDITIONAL SYNC PULSES 4HE CIRCUIT IS FUNCTIONAL WITH COMPOSITE SYNCS WHEN THE SEPARATION OF FIELD SYNC PULSES IS DONE BEFORE THE CIRCUIT IN THIS CASE IN THE PROCESSOR AND WHEN THE FUNCTIONING OF THE PHASEFREQUENCY COMPARATOR IS PREVENTED DURING THE FIELD SYNC PULSE 4HE FIELD SYNC PULSE IS BROUGHT TO PIN THROUGH RESISTOR 2
4HE FORCED CONTROL OF MAXIMUMMINIMUM FREQUENCY
4O PREVENT THE DAMAGE OF THE LINE DEFLECTION OUTPUT STAGE DUE TO A HIGH FREQUENCY IT IS NECESSARY TO PREVENT THE MAXIMUM FREQUENCY OF THE (?$RIVE SIGNAL "ECAUSE THE SYNC PULSES ARRIVE TO THE DEFLECTION DRIVER THROUGH THE PROCESSOR THE MAXIMUM FREQUENCY LOCKOUT IS DONE IN THE PROCESSOR )F THE HORIZONTAL FREQUENCY IS TOO HIGH EXCEEDING K(Z IT IS PREVENTED FROM LEAVING THE PROCESSOR 4HEREBY EVEN IF THE VIDEO CARD WOULD DELIVER A TOO HIGH FREQUENCY THE LINE OUTPUT STAGE WOULD NOT BE DAMAGED 4HE MINIMUM FREQUENCY OF THE (?$RIVE SIGNAL IS ALSO LIMITED ACCORDING TO THE SWITCHED 3
CAPACITORS 4HIS PROCEDURE IS MEANT TO PREVENT THE MONITOR HORIZONTAL DEFLECTION FROM OPERATING IN TOO LOW 3
CAPACITOR COMPARED TO THE FREQUENCY )F THE 3
CAPACITORS ARE TOO SMALL THE !#
VOLTAGE INSIDE THEM WOULD RISE TOO HIGH AND THE HORIZONTAL DEFLECTION OUTPUT STAGE COULD BE DAMAGED 4HIS KIND OF SITUATION MIGHT ARISE FOR INSTANCE WHEN CHANGING THE MONITOR ëMODEì 4HE LOCKOUT CIRCUIT HAS BEEN BUILT IN THE FOLLOWING WAY A SUPPOSED SITUATION WHERE THE HORIZONTAL DEFLECTION FREQUENCY IS DROPPING AND THE !#
VOLTAGE IN THE 3
CAPACITORS STARTS TO GROW # 7HEN THE NEGATIVE PEAKS ARE UNDER 6 THE TRANSISTOR GETS BASE VOLTAGE THROUGH DIODE $ AND RESISTOR 2 &?,)-)4 4 STARTS TO LEAD AND ITS VOLTAGE IS SIMULTANEOUSLY RISING AT ITS COLLECTOR !T THE SAME TIME THE 6#/ CONTROL VOLTAGE TENDS TO RISE THROUGH DIODE $ !T THAT TIME THE FREQUENCY DROP STOPS AND THE CIRCUIT CONTINUES TO OPERATE AT A FREQUENCY WHERE THE NEGATIVE PEAKS OF THE 3
CAPACITORS !#
VOLTAGE ARE APPROX 6 4HE SITUATION IS STABLE UNTIL ADDITIONAL 3
CAPACITORS ARE SWITCHED ON !T THAT TIME THE !#
VOLTAGE IN THE CAPACITORS DECREASES TRANSISTOR 4 STOPS CONDUCTING AND THE FREQUENCY MAY TO DROP IN THE DESIRED LEVEL
4HE (
$RIVE OUTPUT
!N (
$RIVE SIGNAL IS COMING OUT FROM PIN AND THIS IS USED TO CONTROL THE DRIVER TRANSISTOR 4 OF THE HORIZONTAL DEFLECTION OUTPUT STAGE THROUGH BUFFER STAGE 4 AND 4 4HE SAME SIGNAL IS USED TO SYNCHRONIZE THE WIDTH MODULATOR )# "ECAUSE THE PIN OUTPUT IS OF THE OPEN COLLECTOR TYPE PULL
UP RESISTOR 2 IS NEEDED 4HE (
$RIVE SIGNAL PULSE RATIO IS FORMED WITH THE PIN VOLTAGE 2ESISTORS 2 AND 2 ADJUST THE VOLTAGE TO APPROX 6 AT WHICH TIME THE PULSE RATIO IS APPROX 4HE INFORMATION ABOUT THE HIGH VOLTAGE IS BROUGHT TO PIN FROM THE HIGH VOLTAGE GENERATOR )F THE HIGH VOLTAGE RISES TOO HIGH FOR SOME REASON PIN VOLTAGE GOES OVER 6 AND THE )# PREVENTS THE FORMING OF THE (
$RIVE SIGNAL AT WHICH TIME THE HORIZONTAL DEFLECTION AND THE HIGH VOLTAGE GENERATOR ARE SHUT DOWN 4HE )# DOES NOT RESTART UNTIL THE MONITOR HAS BEEN RESTARTED WITH THE POWER SWITCH
4HE PHASE ADJUSTMENT
4HE PHASE ADJUSTMENT IS REALIZED WITH TWO PHASE LOCKS ONE AFTER ANOTHER 0,, AND 0,, 4HESE TWO PHASE LOCKS ARE USED TO ADJUST THE PICTURE POSITION HORIZONTALLY 0,, IS USED TO ADJUST THE PICTURE AND 0,, TO COMPENSATE POSSIBLE TEMPERATURE DRIFT 4HE USER PHASE ADJUSTMENT IS DONE BY CHANGING THE $#
VOLTAGE OF PIN 4HE ADJUSTMENT VOLTAGE IS BROUGHT TO PIN THROUGH RESISTOR 2 FROM THE PROCESSORèS $! TRANSFORMER PIN (?0/3 #
:
FUNCTIONS AS A FILTERING COMPON