HP 85662A Operating instructions

TroubleshootingandRepairManual
HP85662ASpectrumAnalyzerIF-DisplaySection
Wj/Sl HEWLETT
WMM PACKARD
HPPartNo.85662-90085MicrofichePartNo.85662-90086
PrintedinUSADecember1990

@CopyrightHewlett-PackardCompany1990
AllRightsReserved.Reproduction,adaptation,ortranslationwithoutpriorwritten
permissionisprohibited,exceptasallowedunderthecopyrightlaws.
1212ValleyHouseDrive,RohnertPark,CA94928-4999,USA

Certification
Hewlett-PackardCompanycertifiesthatthisproductmetitspublishedspecificationsatthe
timeofshipmentfromthefactory.Hewlett-Packardfurthercertifiesthatitscalibration
measurementsaretraceabletotheUnitedStatesNationalInstituteofStandardsand
Technology,totheextentallowedbytheInstitute’scalibrationfacility,andtothecalibration
facilitiesofotherInternationalStandardsOrganizationmembers.
Warranty
ThisHewlett-Packardinstrumentproductiswarrantedagainstdefectsinmaterialand
workmanshipfora periodofoneyearfromdateofshipment.Duringthewarrantyperiod,
Hewlett-PackardCompanywill,atitsoption,eitherrepairorreplaceproductswhichproveto
bedefective.
Forwarrantyserviceorrepair,thisproductmustbereturnedtoa servicefacilitydesignated
byHP.BuyershallprepayshippingchargestoHPandHPshallpayshippingchargesto
returntheproducttoBuyer.However,Buyershallpayallshippingcharges,duties,andtaxes
forproductsreturnedtoHPfromanothercountry.
HPwarrantsthatitssoftwareandfirmwaredesignatedbyHPforusewithaninstrument
willexecuteitsprogramminginstructionswhenproperlyinstalledonthatinstrument.HP
doesnotwarrantthattheoperationoftheinstrument,orsoftware,orfirmwarewillbe
uninterruptedorerror-free.
LimitationofWarranty
Theforegoingwarrantyshallnotapplytodefectsresultingfromimproperorinadequate
maintenancebyBuyer,Buyer-suppliedsoftwareorinterfacing,unauthorizedmodificationor
misuse,operationoutsideoftheenvironmentalspecificationsfortheproduct,orimproper
sitepreparationormaintenance.
NOOTHERWARRANTYISEXPRESSEDORIMPLIED.HPSPECIFICALLY
DISCLAIMSTHEIMPLIEDWARRANTIESOFMERCHANTABILITYANDFITNESS
FORA PARTICULARPURPOSE.
ExclusiveRemedies
THEREMEDIESPROVIDEDHEREINAREBUYER’SSOLEANDEXCLUSIVE
REMEDIES.HPSHALLNOTBELIABLEFORANYDIRECT,INDIRECT,SPECIAL,
INCIDENTAL,ORCONSEQUENTIALDAMAGES,WHETHERBASEDON
CONTRACT,TORT,ORANYOTHERLEGALTHEORY.
Assistance
Product maintenance agreements and other customer assistance agreements are available for
Hewlett-Packard products.
For any assistance, contact your nearest Hewlett-Packard SalesandServiceOffice.
iff

SafetySymbols
Thefollowingsafetysymbolsareusedthroughoutthismanual.Familiarizeyourselfwitheach
ofthesymbolsanditsmeaningbeforeoperatingthisinstrument.
Caution
•
Thecaution signdenotesa hazard.Itcallsattentiontoa procedurewhich,
ifnotcorrectlyperformedoradheredto,couldresultindamagetoor
destructionoftheinstrument.Donotproceedbeyonda caution signuntilthe
indicatedconditionsarefullyunderstoodandmet.
Warning
0 Thewarning signdenotesa hazard.Itcallsattentiontoa procedurewhich,
ifnotcorrectlyperformedoradheredto,couldresultininjuryorlossoflife.
Donotproceedbeyonda warning signuntiltheindicatedconditionsarefully
understoodandmet.
GeneralSafetyConsiderations
Warning
0 Before this instrument is switched on, makesureithasbeenproperlygrounded
throughtheprotectiveconductoroftheacpowercabletoa socketoutlet
providedwithprotectiveearthcontact.
Anyinterruptionoftheprotective(grounding)conductor,insideoroutside
theinstrument,ordisconnectionoftheprotectiveearthterminalcanresultin
personalinjury.
WarningTherearemanypointsintheinstrumentwhichcan,ifcontacted,causepersonal
injury.Beextremelycareful.
9Anyadjustmentsorserviceproceduresthatrequireoperationoftheinstrument
withprotectivecoversremovedshouldbeperformedonlybytrainedservice
personnel.
Caution
•
Before this instrument is switched on, makesureitsprimarypowercircuitry
hasbeenadaptedtothevoltageoftheacpowersource.
Failuretosettheacpowerinputtothecorrectvoltagecouldcausedamageto
theinstrumentwhentheacpowercableispluggedin.

Contents
IF-DisplaySectionGeneralinformationonthecontentsofthemanual,includingstorage,
GeneralInformationshipment,andpackaging.
IFOverallBlockMnemonicTable,InstrumentBusPinConnectionTable,andOverall
DiagramIFBlockDiagram.
AlDisplaySectionAlDisplaySectionTroubleshootinginformation,BlockDiagram,and
A1A1throughA1A10servicesheets.
A3DigitalStorageA3DigitalStorageTroubleshootinginformation,BlockDiagram,and
TroubleshootingA3A1throughA3A10servicesheets.
A4IFSectionA4SectionBlockDiagram,andA4A1throughA4A10servicesheets.
Troubleshooting
OptionsInformationandservicesheetsthatexplainthedifferencebetweenan
IF-DisplaySectionwithanoptionanda standardIF-DisplaySection.
GeneralPartsListingReplaceablepartsinformationandpartsidentificationfigures.
MajorAssemblyandMajorassemblyandcomponentlocations.
ComponentLocations
Contents1

IF-DisplaySectionGeneralInformation
IF-DisplaySectionService
Introduction
ThisTroubleshootingandRepairManualcontainsinformationfor thetroubleshootingand
repairoftheIF-DisplaySectionoftheinstrument.Thisinformationiscombinedinservice
sheetsandindexedwithtabsforquickreference.
InstrumentsCoveredbyThisManual
-HP85662AIF-DisplaySections,serialnumberprefixes2403Aandabove.
-Option067(1kHzto3 MHzResolutionBandwidthsfortheHP8567ASpectrumAnalyzer),
■Option400(400Hzoperation)
-Option462(ImpulseBandwidths)
-OptionH96(30Hz-lMHzResolutionBandwidths)
HP85662AIF-DisplaySectionswithserialnumberprefixesbelow24038arecoveredinboth
Volume3 oftheHP8566AOperatingandServiceManual(HPpartnumber08566-90006)and
Volume3 oftheHP85688OperatingandServiceManual(HPpartnumber08568-90012).
HowtheHP85662AIsUsed
-HP85662AIF-DisplaySectionisusedwith:
□HP85660BRFSectionastheHP8566BSpectrumAnalyzer
□HP85680BRFSectionastheHP8568BSpectrumAnalyzer.
■Option462isusedwith:
□HP85660BRFSectionastheHP8566BOption462SpectrumAnalyzer
□HP85680BRFSectionastheHP8568BOption462SpectrumAnalyzer
-Option067isusedwith:
□HP856708RFSectionastheHP85678SpectrumAnalyzer
-OptionH96isusedwith:
•I HP85680BOptionH96astheHP8568BOptionE96SpectrumAnalyzer
oHP85680BOptionH44astheHP8568BOptionE44SpectrumAnalyzer.
IF-DisplaySectionGeneralInformation1

ServiceSheets
Theservicesheetsinthismanualareorganizedinalpha-numericorderandareindexedwith
tabstomakeiteasytolocatea specificservicesheet.Eachoftheservicesheetscontainthe
followinginformation:
■CircuitDescription(wherepractical)
■TroubleshootingHints(wherepractical)
-ReplaceablePartsLists
■BlockDiagram(wherepractical)
-ComponentLocationIllustrations
-SchematicDiagrams
RepairProcedures
Repairproceduresareincludedforuseinremovingandreplacingassembliesforrepair.They
arelocatedinthefollowingsections:
■Front-PanelLEDReplacement
Tab: AlAlKeyboard
■FrontPanelRemovalandRepair
Tab: AlAlKeyboard
-CRTReplacement
Tab: A1A3HighVoltageRegulator
■IF-DisplaySectionInternalFuseReplacement
Tab: A1A6±15V RegulatorandHighVoltage
MajorAssemblyandComponentLocations
MajorassemblyandcomponentlocationillustrationsfortheIF-Sectionarelocatedattherear
ofthismanual.
Troubleshooting
TroubleshootinginformationfortheIF-Sectionisdividedintotwolevelsasfollows:
-SectionLevel
IFOverallBlockDiagrarn
AlDisplaySectionBlockDiagram
A3DigitalStorageTroubleshooting
A4IF-SectionTroubleshooting
-AssemblyLevel
Mostassemblieshavetroubleshootinghintsimmediatelyfollowingtheircircuit
descriptions.Troubleshootinginformationisalsolocatedonassembly-levelblock
diagrams,notes,andschematics.
2If-DisplaySectionGeneralInformation

AllassembliesareindexedbytabexceptfortheoneslistedinTable1 attheendofthis
section.Table1 liststheindextabswheretheseassembliescanbefound.
AssemblyLocations
IAssembly| TabLocationI
A1T1
A1V1
A1A11
A2
A1A8Rectifier,BlockDiagram
GeneralPartsListing,Table6
A1A3HighVoltageRegulator,BlockDiagram
GeneralPartsListing,Table6
A1A3HighVoltageRegulator,BlockDiagram
GeneralPartsListing,Table4
NotAssigned
StorageandShipment
Environment
Theinstrumentmaybestoredorshippedinenvironmentswithinthefollowing limits:
Temperature-40°Ct o +75°C
Humidity ...............................................m\5%
t 0 90%at0°to40°C
Altitude.Upto15,240meters(50,000feet)
Theinstrumentshouldbeprotectedfromtemperatureextremeswhichmightcause
condensationwithintheinstrument.
OriginalPackaging
Itisrecommendedthattheoriginalfactorypackagingmaterialsberetainedforusewhen
shippingtheinstrument.Iforiginalpackagingmaterialcannotberetained,packaging
materialsidenticaltothoseusedinfactorypackagingareavailablethroughHewlett-Packard
offices.PartnumbersanddescriptionsofthepackagingmaterialsarelistedinFigure1.
Thecombinedweightofthetwoinstrumentsectionsisapproximately50kg(112lbs).
Becauseoftheweightinvolved,donotpackagetheinstrumentsectionsfastenedtogetheras
oneunit.Theinstrumentsectionsmustbeseparatedandpackagedinseparatecontainers.
ThequantityofpackagingmaterialsinFigure1 isforonlyoneinstrumentsection.
IftheinstrumentisbeingreturnedtoHewlett-Packardforservicing,attacha tagtoeach
cartonindicatingthetypeofservicerequired,returnaddress,modelnumber,andfullserial
number.Foryourconvenience,a supplyoftagsisincludedattheendofthissection.Also,
markeachcontainerFRAGILEtoassurecarefulhandling.Inanycorrespondence,refertothe
instrumentbymodelnumberandfullserialnumber.
OtherPackaging
Ifitisnecessarytousepackagingmaterialsotherthanthetypeusedinoriginalfactory
packaging,thefollowinggeneralinstructionsshouldbefollowed.
IF-DisplaySectionGeneralInformation3

1. Separatethetwoinstrumentsectionsandwrapeachinheavypaperorplastic.
2. Placetheinstrumentsectionsinseparatecontainerswith8 to10cm(3to4 inches)of
shock-absorbingmaterialaroundallsidestoprovidefirmcushioningandpreventmovement
insidethecontainer.Protectfrontpanelswithcardboard.Double-wallcorrugatedcartons
of125kg(275lb)burstingstrengtharesufficientforshippingcontainers.
3. Sealeachcontainersecurelyand,ifshippingtoa Hewlett-Packardofficeorservicecenter,
attacha tagtoeachcontainerindicatingthetypeofservicerequired,returnaddress,model
number,andfullserialnumber.Foryourconvenience,a supplyoftagsisincludedatthe
endofthissection.
4. MarkeachcontainerFRAGILEtoassurecarefulhandling.
ITEM QTY
1
2
1
HPPARTNO.
9211-4487
5180-2319
5180-2320
DESCRIPTION
OUTERBOX
INNERFOAMPAD
INNERBOX
Figure1.PackagingforShipmentUsingFactoryPackagingMaterials
4IF-DisplaySectionGeneralInformation

IFOverallBlockDiagram
Table1.A3DigitalStorageMnemonic Table
Mnemonic Description Mnemonic Description
18.4MHZLO
[MHZ
21.4MHZ
3MHZ
ALOG
AO- All
AlOdB
A20dB
A2dB
A4dB
A.8dB
AJDRO
ADR3
kUX BLANK
<OJXZ
WdB
BLOG
BO- Bll
BLO- BL6
BLINK
BRIGHT
BS
BWS
BW63
BW68
BW7
2HAR
3LK
18.4MHzLocalOscillatorSignal
1MHzADCClock
21.4MHzIFSignal
3MHzIFSignal
LogExpandControl
AccumulatorBusBits0 through11
AttenuationControls
InstrumentBusAddressBits0 through3
AuxiliaryBlankingOutput
AuxiliaryZ AxisOutput
AttenuationControl
LogExpandControl
DigitalStorageBusDataBits0 through11
BranchLengthBusBits0 through6
BlinkCRTDisplayControl
BrightCRTDisplayControl
BlockSwitchControl
BandwidthControls
MemoryChipEnable
CharacterModeDisplayControl
8MHzSystemClock
LDRMP
LDSR
LDX
LDY
LFSEN
LG10
LG20
LGCLK
LGX
LGY
LINCRSA
LINTG
LL
LLGBLANK
LLL
LMEMEN
Log/LinearControl
LQ
LROMEN
LRSTO
LRTN
LRTRC
LT10
LTON
LTSTA
LTSTB
LWRITE
LZERO
MA0-MA11
LoadRampRegister
LOW= DigitalStorageReady
LoadX PositionRegister
LoadY PositionRegister
LOW= FastSweepEnable
LinearGainControls
200kHzLineGeneratorClock
LineGeneratorHorizontalSignal
LineGeneratorVerticalSignal
IncrementStrokeAddress
LOW= IntegratorControl
LongLine
LOW= LineGeneratorBlankingControl
LOW= LongLine
LOW= EnableMemoryOutput
LOW= SelectedQualifier
LOW= ROMEnable
LOW= ResetTriggerOccurred
LOW= EnableInterruptReturn
LOW= RetraceSignal
LOW=IF-DisplaySection1/0Strobe
LOW= TurnOn
LOW= InputTestA Data
LOW= InputTestB Data
MemoryWriteControl
OutputofZeroCheckonALUResult
MemoryAddressBusBits0 through11
IFOverallBlockDiagram

Table1.A3DigitalStorage Mnemonic Table(continued)
Mnemonic
CRTDSBL
AX
AY
DIM
DOTEN
FO- Fll
FCO- FC3
PSO- PS3
FREQZERC
FS
FSOUT
FSZ
HLDX
HLDY
HOLD
HSWP
tCLK
INSELA
INSELB
INTG
[NTR
tOBO
[OB15
[OC
KSO- KS3
JO- L7
LADC
.BLANK
,CLK
LCLRSA
LDCHAR
LDEXP
LDMEN
LDMAR
JDMDR
Description
CRTDisableControl
DeltaX Position
DeltaY Position
DimCRTDisplayControl
DotEnable
FunctionBusBits0 through11
DataManipulatorFunctionControlBits C
thru3
1/0PortSelectionBits0 through3
FrequencyZeroControl
FastSweepMode
FastSweepOutput
FastSweepZ Axis
HoldX Position(SampleandHoldControl
HoldY Position(SampleandHoldControl
TrackandHoldControl
HIGH= Sweeping
IndicatorClock(Front-PanelLEDs)
InputSelectionBitA
EnputSelectionBitB
IntegratorControl
tnterrupt
instrumentBusDataBits0 through15
L/0PortInput/OutputControl
ConstantSelectionBits0 through3
jinkStateBusBits0 through7
,0W= EnableADCOutput
,0W=BlankingControl
nvertedCLK
LOW= ClearStrokeAddress
LoadCharacterRegister
joadExpandRegister
DataManipulatorOutputEnable
.>oadMemoryAddressRegister
joadMemoryDataRegister
Mnemonii
NSO- NS7
0S10
OS20-1
DS20-2
PENLIFT
=0S
QSO- QS3
R.0- R 11
RBWA
RBWB
RBWC
RBWD
RECCAL
IECZERO
IMO- RM2
RSEN
RSHS
30- Sll
30-S7
5G10
5G20-1
SG20-2
»MPL
JTROK8
SWITCH
«WA
^BWB
/BWC
/BWD
/IDEO
C
{
r
Description
NextStateBusBits0 through7
OffsetGainControls
RecorderPENLIFTControl
SignofALUResults
QualifierSelectionBits0 through3
RamBusBits0 through11
ResolutionBandwidthControls
RecorderCalibrate
lecorderZero
lamRegisterSelectBits0 through2
ResetPeakDetectorsEnable
ResetHighSweep
SourceBusBits0 through11
StateBusBits0 through7
StepGainControls
■ample
Itroke8 ofCurrentCharacter
Jp/DownConverterControl
IdeoBandwidthControls
/ideoSignal
lorizontalSignaltoCRT
VerticalSignaltoCRT
ntensitySignaltoCRT
2IFOverallBlockDiagram

Table2.50-WireInstrumentBusPinConnectionTableforIF-DisplaySection
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Signal
GND
NC
IOBO
IOBI
IOB2
IOB3
IOB4
IOB5
IOB6
IOB7
IOB8
IOB9
IOB10
IOB11
IOB12
IOB13
IOB14
IOB15
NC
NC
NC
HPON
ADRO
ADRl
ADR2
Description
Ground
NoConnection
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
InstrumentBusDataBits0 -
15
15
15
15
15
15
15
15
15
15
15
15
15
15
InstrumentBusDataBits0-15
InstrumentBusDataBits0-15
NoConnection
NoConnection
NoConnection
HIGH= IF-DisplaySection
PowerON
InstrumentBusAddressBits0 - 4
InstrumentBusAddressBits0 - 4
InstrumentBusAddressBits0 - 4
Pin
26
27
28
29
30
31
32
33
34
35
36
37
39
40
41
42
Signal
ADR3
ADR4
ADRS
NC
NC
KR8
KR9
KR10
KR11
KC0
KCI
KC2
KC4
KCS
KC6
KC7
Description
InstrumentBusAddressBits0 - 4
InstrumentBusAddressBits0 - 4
AddressBit5 notused
NoConnection
NoConnection
KeyRows8-11
KeyRows8-11
KeyRows8-11
KeyRows8-11
KeyColumns0 - 7
KeyColumns0 - 7
KeyColumns0 - 7
KeyColumns0 - 7
KeyColumns0 - 7
KeyColumns0 - 7
KeyColumns0 - 7
43LSTPL3W= StopProcessor
44HSWPHIGH= Sweeping
45LSRQX>W~ ServiceRequest
46LDSRX>W= DigitalStorageReady
47LB10LOW= RFSectionI/OStrobe
48GNDGround
49LT10LOW= IF-DisplaySectionI/O
50 GND Ground
IFOverallBlockDiagram3

F-DISPLAYSECTION
RF~SECT"ON1
21.4MHzIF
21,4MHzIF—I
SWEEP
->>
-»
J 1-3
^
IF-DISPLAY SECTION
I J15^
CJ VIDEOTOA3A9TRACKANDHOLD
J15
W
W35
W33
W34
W25
PENLIFT(FROMA3A1)
RECORDER.
OUTPUTS-<VIDEO
V SWEEP
21.4MHzIFOUTPUT
W30 <-5dBm>
r
DISPLAY
OUTPUTS <
V.
BLANK
[A4A8ATTENUATORBANDWIDTHFILTER] [A4A6A2DOWNCONVERTER~~|
[A4A73MHZH
BANDWIDTHi
FILTERi
AUXSWEEP0 TO10VOLTS
SWEEPINPUT0 TO10VOLTS
RECORDERVIDEOOUTPUT0 TOIV
RECORDERSWEEPOUTPUT0 TO10V
21.4MHzIFOUTPUT
[A4A6A1" UPCONVERTER"
!-£>
1
<+4dBm>
RESBW>1KHz I
RESBW<1KHzJ
21.4MHz
..Jl_
IFOUTPUTTOFREQUENCYCOUNTER
A
18,4MHz 1 POLE
[A4A5STEPGAIN| [A4A4BWFI LTER~|
LCPOLES(2)I
[A4A3LOGAMPF ILTE~R]|~?A4A2LOGAMP-DETECTOR-1
<+5dBm>
0TO50dB
A=10dB-15,9TOOdB
A=0.1dB
J^>ww«
18.4MHz
J L
K"Y>-W-FREQZERO
/V/(FROMA1A1)
<-3dBm>
A
A
LOG/L I N
(5STAGES)
!<+10dBm>l
■>—■A
STEP
GAIN
CONTROL
AUXX (FROMA1A4ORA1A2)(SEENOTE2)
AUXV (FROMA1A5ORA1A2)(SEENOTE2)
AUXZ (FROMA3A2)
AUXBLANK(FROMA3A2)
[A4A9IFCONTROL'/9
LINEIN>
EXTERNALI ,
TRIGGER> (85
INPUTI
W26 ^
LINEMODULE
TRANSFORMER
[A1A9BUS"1
TRANSITION1
11
-0
■. XTALPLOES(3)■
/
L__
30MHz
LOG/LIN
(4STAGES) DETECTOR
LG10
50WIRE* ' ' V>l
INSTRUMENTt i
BUSTOA15I I
CONTROLLERI *
J2 50WIREINSTRUMENTBUS
I
I
I
JL
|~A4A1VIDEOPROCESSOR
<1V>I m
1
LOGA IN
JL
AUXSWEEP
T~1
3 X
SWEEPINPUT
LOGOFFSET
VIDEOBW.LOGEXPAND,RECORDERCALIBRATION
J
(SEENOTE2)
[A1A6+/-15VREG~'L
H.V.POWERSUPPLY
A1A7+100V,
+5.2VREG
A1A8RECTIFIER
ni
NETRIGGER
+100V/+120V(SEENOTE2)
+15V
+5.2V
-15V
HVOSCILLATOR
-7*-
50WIREINSTRUMENTBUS
SWEEP
TOA3A8
A-DCONVERTER
LINETRIGGER
TOA3A1TRIGGER
HVOSCILLATOR
TOA1A3
HIGHVOLTAGE
REGULATOR
50WIRE
/////£*ZA INSTRUMENTBUS
EXTERNALTRIGGER
'TOA3A1TRIGGER
NOTES:
1.UNLESSOTHERWISEINDICATED,POWERLEVELS
AREMEASUREDUNDERTHEFOLLOWINGCONDITIONS
USINGANACTIVEPROBEANDTHESPECTRUM
ANALYZER.
INSTRUMENTPRESET
CENTERFREQUENCYCALOUTFREQ.
FREQUENCYSPAN0 Hz
ATTENUATION0 dB
RESOLUTIONBANDWIDTH3KHz
2. IF-DISPLAYSECTIONSWITHSERIALNUMBER
PREFIXES3004AANDABOVEHAVETHEFOLLOWING
CHANGES.
—THEA1A2 Z-AXIS APLIFIER,THEA1A4X
DEFLECTIONAMPLIFIER,ANDTHEA1A5Y
DEFLECTIONAMPLIFIERWEREINCORPORATED
INTOTHEA1A2XYZDRIVERAMPLIFIER.
—THEA1A6+/-15VREGULATORWASCHANGEDAND
HASBEENRENAMEDTHEA1A6HIGHVOLTAGE
POWERSUPPLY.
—THEA1A7+100V,+5.2VREGULATOR+100V
OUTPUTHASBEENCHANGEDTOTHE+120V.
—THEA1A11HIGHVOLTAGEMULTIPLIERHAS
BEENINCORPORATEDONTOTHEA1A3A1HIGH
VOLTAGEMODULE.
F-DISPLAYOVERALL,BLOCKDIAGRAM(1OF2)

IF-DISPLAYSECTION
/ VIDEOFROM.
BACKPANELA4A1
VIDEOPROCESSOR
SWEEPFROM
RFSECTION
LINETRIGGER
FROMA1A8-
RECTIFIER
HVOSCILLATOR
FROMA1A6—
+15V
REGULATOR/
HIGHVOLTAGE
POWER
SUPPLY
(SEENOTE2)
EXTERNAL
TRIGGER—
FROMREAR
PANEL
INSTRUMENT
SEENOTE2
NOTES:
~l
\
A1V
CRT
■< AUXY
-<AUXX
7
VERTICAL
DEFLECTION
PLATES
A
y
HORIZONTAL
DEFLECTION
PLATES
-On
1.UNLESSOTHERWISEINDICATED,POWERLEVELS
AREMEASUREDUNDERTHEFOLLOWINGCONDITIONS
USINGANACTIVEPROBEANDTHESPECTRUM
ANALYZER,
INSTRUMENTPRESET
CENTERFREQUENCYCALOUTFREQ.
FREQUENCYSPAN0 Hz
ATTENUATION0 dB
RESOLUTIONBANDWIDTH3KHz
2. IF-DISPLAYSECTIONSWITHSERIALNUMBER
PREFIXES3004AANDABOVEHAVETHEFOLLOWING
CHANGES.
—THEA1A2Z AXISAPLIFIER,THEA1A4X
DEFLECTIONAMPLIFIER,ANDTHEA1A5Y
DEFLECTIONAMPLIFIERWEREINCORPORATED
INTOTHEA1A2XYZDRIVERAMPLIFIER.
—THEA1A6 +/-15V REGULATORWASCHANGEDAND
HASBEENRENAMEDTHEA1A6HIGHVOLTAGE
POWERSUPPLY.
—THEA1A7+100V,+5.2VREGULATOR+10OV
OUTPUTHASBEENCHANGEDTOTHE+120V.
—THEA1A11HIGHVOLTAGEMULTIPLIERHAS
BEENINCORPORATEDONTOTHEA1A3A1HIGH
VOLTAGEMODULE.
POST
ACCELERATOR
[A"1A3HIGHVOLTAGEl
■REGULATOR
HVOSCILLATOR
EXTTRIGER EXTTRIGGER
CONTROLGATE
FOCUSGATE
INTENSITYLIMIT
HVOSCILLATOR
[A1A11~~|
jHIGHVOLTAGE'
IMULTIPLIERI
I(SEENOTE2)I
l___ ..J
J
IF-DISPLAYOVERALLBLOCKDIAGRAM(2OF2)

A1
DisplayTroubleshooting
TheDisplaysystemconsistsoffour sections:
InputSectionA3A8Analog-DigitalConverterandA3A9TrackandHold
ProcessorSectionA3A4Memory,A3A5DataManipulator,A3A6MainControl,
andA3A7Interface
CRTDriverSectionA3A1Trigger,A3A2IntensityControl,andA3A3Line
Generator.
CRTAmplifierSectionA1A3HighVoltageRegulatorandeitherA1A2XYZDriver
Amplifier(SerialPrefixes3004Aandabove)orA1A2Z Axis
AmplifierA1A4X DeflectionAmplifierandA1A5Y Deflection
Amplifier
Isolationofa malfunctiontooneoftheabovesectionsisdonewiththeuseofrear-panel
displayoutputsandtheinternaltestprograms.
IftheleftINSTRCHECKLEDison,a failurehasprobablyoccurredinDigitalStorage.
RefertotheA3DigitalStorageTroubleshootingnotesforthecorrecttroubleshooting
procedure.
Thefollowingparagraphsbrieflydescribethefailuremodesandappropriateplacestobegin
thetroubleshooting.
CharactersOnly
IfonlythecharactersontheCRTdisplayareaffected,theproblemmostlikelyexistsonthe
A3A4Memory.
GraticuleandCharactersOnly
Ifthegraticuleandcharactersareincorrect,butthevideoinformationappearstobecorrect,
suspecttheSystemROMsonA3A6first.Alsothe“longPOP”testoftheRFSection
memoryshouldbeperformed.RefertotheDigitalStorageTroubleshootingnotesformore
information.
Al1

Video(Signal)Only
Ifonlythevideoinformationisincorrect,suspectA4IFSection,A3A8,orA3A9.To
eliminatetheIF,connecttherear-panelSWEEPandVIDEORECORDEROUTPUTStoan
oscilloscope.Ifthevideoiscorrect,theneitherA3A8orA3A9isdefective.
Removecable96from A3A9J1. ThenjumperA3A8TP1toA3A9TP3andpushInstrument
Preset.Thissubstitutesthesweeprampforthevideoinput.TheCRTdisplayissimilar
toFigure7 intheA3A8tab.Iftherampisincorrect,removeA3A9,jumperA3A8TP1to
A3A8TP6andpushInstrumentPreset.TheCRTdisplayisthesameasFigure7 inthe
A3A8tab.Ifthedisplayiscorrect,theproblemisintheA3A9assembly.RefertoA3A9
Troubleshootingprocedure.Iframpisincorrect,suspectADConA3A8.SeetheA3A8
Troubleshootingnotestoverifythis.
Don’truleoutthesweepsystem,especiallytherampconverteronA3A8,when
troubleshootingvideofailures.SomerampconverterfailuresproduceCRTdisplaysthatare
similartothosecausedbyADCfailures.
AllCRTInformationBlankorDistorted
CheckX,Y,andZ DISPLAYOUTPUTSonrearpanel.Ifthesearecorrect,thefaultismost
likelywiththeX/YDeflectionAmplifiersorZ AxisAmplifier(orA1A2XYZDeflection
Amplifier).Thefollowingprogram,whichplacesa dotatthecenterofthedisplay,ishelpful
whentroubleshootingtheDeflectionAmplifiers.Itbalancesthevoltagesinbothhalvesofthe
circuitry.PressInstrumentPresetandkeyinthefollowing:
BlankTraceA,fsHirT),RecorderLowerLeft,0 HzDSPLADRS
(SHIFT K RecorderUpperRightWRITE
1090HzVectorCommand
512 HzX coordinatesforcenterscreen
512HzY coordinatesforcenterscreen
IftheX,Y,andZ DISPLAYOUTPUTSproduceeitherdistortedornooutput,Digital
Storagemustbetested.Connecta jumperfromA3A6TP3toA3A6TP6andpushA3A7S1.
TheDigitalStorageTestPattern(Figure1 oftheA3DigitalStorageTroubleshootingtab)
results.RefertotheDigitalStorageTroubleshootingprocedures.Ifthetestpatterniscorrect,
startwiththesystemROMscheck.
Ifthetestpatternisincorrect,verifyoperationofA3A3LineGeneratorandA3A2Intensity
Control.Refertothetroubleshootinginformationincludedwiththeschematics.IfA3A3and
A3A2areworkingproperly,thenallofDigitalStoragewillhavetobechecked,startingwith
A3A6.
Wheneverthedisplayisblank,andtheleftINSTRCHECKLEDisoff,checktheA1A6
±15V Regulator(orA1A6HighVoltagePowerSupply)andA1A7+100V,+5.2V
Regulator.ThepowersupplyLEDsindicatethepresenceofvoltagebutnotregulation.Verify
operationofA3A2IntensityControlandA1A2Z AxisAmplifier.Iftheseareallworking
properly,carefullyexaminetheA1A3HighVoltageRegulatorassembly.
IftheCRTisblank,checktheCRToscillatortoseeifitisturnedoff.MeasureA1A6TP6
witha DVM.IfTP6isa digitalhigh,theCRTwillnotoperatesincetheoscillatoristurned
off.TroubleshootA1A6tocheckforbadcomponents,shorts,andsoforth.IftheA1A6is
operatingcorrectly,checktheCRTdisablelinefromA4A9U14.IftheICisdamaged,it
2Al

cancausetheCRTtobedisabled.IfU14isoperatingcorrectly,visuallyinspecttheA4A9
assembly.
Al3

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NOTES:
1.A1A2 XYZ DRIVERAMPLIFIER
INCORPORATED A1A2 Z-AXIS
AMPLIFIER, A1A4 X-DEFLECTION
AMPLIFIER, ANDA1A5 Y-DEFLECTION
AMPLIFIERASSEMBLIES ON SERIAL
NUMBERPREFIXES3004A AND ABOVE.
2. FOR SERIALNUMBERPREFIXES3004A
ANDABOVE, A1A3ANDA1A6 ASSEMBLY
INFORMATION ISNOT CURRENT.REFER
TO A1A3TABAND A1A6/A1A7 TABFOR
CURRENTBLOCKDIAGRAMS.
V V
7,25 18,36
V V _.J
CRTDISABLEFROM
A4A9 IF CONTROL
/
A1 DISPLAY SECTION, BLOCKDIAGRAM

A1A1
A1A1Keyboard,CircuitDescription
A1A1Keyboardconsistsofthreefunctionalblocks:CRTControls,KeyboardSwitches,and
StatusIndicators.
CRTControls(A)
TheCRTControlsincludethefollowingfront-panelpotentiometers:
■INTENSITYcontrolRl.SetstheleveloftheinputtoA1A2Z AxisAmplifier.
■ALIGNscrewdriveradjustmentR8.SetstheCRTtracetohorizontal.
-FOCUSscrewdriveradjustmentR2.FocusestheCRTtrace.
■FREQZEROscrewdriveradjustmentR3.Forresolutionbandwidthsof1 kHzorless,
adjuststhefrequencyofthe18.4MHzoscillator(A4A5StepGain)topreciselyaligntheIF
passbandto21.400MHz.
Thefront-panelSTANDBYindicator,LEDDS16,whichisdrivenbythePWRDWNsignal
fromA1A6±15V Regulator,isactivatedwhenlinepowerisappliedwhilethepowersupply
regulatorsareoff.
KeyboardSwitches(B)
TheKeyboardSwitchesarea matrixofrowsandcolumnsconnectedtotheRFSection
keyboardbythe50-wireInstrumentBusW8.Whena keyboardswitchisactivated,Al5
Controllerrecognizestheswitchandperformstheindicatedoperation.
StatusIndicators(C)
The17StatusIndicators,LEDsDSlthroughDS15,DS17,andDS18,showthestatesofthe
variouskeyboardfunctions.Al5ControllerloadsthelatchesUlandU2viatheInstrument
BusW8.ThelatchaddressisdecodedinA3A1Trigger,whichgeneratestheICLKstrobe
signal.
Front-PanelLEDReplacement
1. SetinstrumentLINEswitchtoSTANDBY.
2. LoosensetscrewsinINTENSITYcontrolandVideoTriggerLEVELcontrolknobs® and
©andremoveknobs.SeeFigure1.
A1A11

FRONTPANELVIEW
J^
IV
□o a □ n □ □
*.'□ □ □ □ □ □ □
*□ □ a □ □ □ db
£'
Figure1.FrontPanelControlKnobs
3. RemovenutfromINTENSITYcontrolandfromVideoTriggerLEVELcontrolusinga
5/16-inchwrench.
4. Thedresspanelisnowloose.Itmaybenecessarytopryfrontpaneloutslightlyusinga
sharpinstrumentsuchasa knifebladealongtheedgeofthepanel.
5. RemovetheFrontPanelbyremovingthe8 screws© arounditsedge.TheLEDsarenow
accessibleforreplacement.UnsoldertheleadsoftheLEDfromtherearoftheprinted
circuitboard.PullouttheLEDandits standoff. Inserta newLEDinthestandoffand
replaceitontheboardwiththenegativelead(cathode)tothesquarepadontheprinted
circuitboard.RefertoFigure2 foridentificationofLEDleads.Solderleadstoprinted
circuitboardandtrimexcessleadlengthandreassemblethefrontpanel.
2A1A1