HP 8901B User manual

HP 8901B
MODULATION ANALYZER
Service Manual
SERIAL NUMBERS
This manual provides complete information for in-
struments
with serial-numberprefixes:
2314A to 2914A and all MAJOR changesthat occur to your instrument.
rev. 12NOV92
For additional important information about serial
numbers, refer
to "INSTRUMENTS COVERED BY
THIS MANUAL" in Section 1.
Fourth Edition
This material may be reproducedby or for the US.
Government pursuant to the Copyright License un-
der the clause at DFARS 52.227-7013 (APR 1988).
Copyright@HEWLETT-PACKARD COMPANY 1987
EAST 24001 MISSION AVENUE, TAF C-34, SPOKANE, WASHINGTON, U.S.A. 99220
Service Manual (Volume 1, 2, 3) HP Part 08901-90114
Other DocumentsAvailable:
Operation and Calibration Manual HP Part 08901-901
13
Basic Operationand Application Guide 08901-901 17
MicroficheOperationand Calibration Manual HP Part 08901-90115
MicroficheService Manual
HP Part 08901-90116 Printed in USA. : April 1995
HEWLETT
Pia PACKARD

1 Regulatory Information
(Updated March 1999)
1

Regulatory Information(Updated March 1999)
SafetyConsiderations
GENERAL
This product and related documentation must be reviewed for familiarization with safety
markings and instructions before operation.
This product has been designed and tested in accordance with IEC Publication 1010,
"Safety Requirements for Electronic MeasuringApparatus," and has been supplied in a
safe condition. This instruction documentation contains information and warnings which
must be followed by the userto ensuresafeoperation and to maintain the product
in a safe
condition.
SAFETY EARTH GROUND
A uninterruptible safety earthground must be provided from the main power source to the
product input wiring terminals, power cord, or supplied power cord set.
SAFETY SYMBOLS
A Indicates instrument damage can occur if indicated operating limits are exceeded.
A Indicates hazardous voltages.
4 -
Indicates earth (ground)terminal
WARNING A WARNING note denotesa hazard.It calls attentionto a procedure,
practice, or the like, which, if not correctlyperformedor adhered to,
could result in personal injury. Do not proceed beyond a WARNING
sign until the indicated conditions are fully understood and met.
CAUTION A CAUTION note denotes a hazard. It calls attentionto an operation
procedure, practice, or the like, which, if not correctly performed or adhered
to, could result in damage to or destruction of part or
all of the product. Do
not proceed beyond an CAUTIONnote until the indicated conditions are fully
understood and met.
2 Chapter 1

Regulatory Information (Updated March 1999)
Safety Considerations for this Instrument
WARNING
This product is a SafetyClass I instrument (providedwith a
protective earthingground incorporated in the power cord).The
mainsplugshall only be inserted in
a socket outlet providedwith a
protective earthcontact. Any interruption of the protective
conductor inside
or outside of the product islikely to make the
product dangerous.Intentional interruption
is prohibited.
Whenever it is likely that the protection hasbeen impaired, the
instrument must be made inoperative and be securedagainst any
unintended operation.
If this instrument is tobe energized via an autotransformer (for
voltagereduction), make surethe common terminalis connectedto
the earthterminal of thepower source.
If this product is not used as specified, theprotection provided by
the equipment could be impaired. This product must beused in a
normal condition (inwhich
all means for protection areintact)only.
No operatorserviceablepartsinthisproduct. Refer servicing to
qualified personnel. To prevent electrical shock, do not remove
covers.
Servicinginstructionsarefor use by qualified personnel only. To
avoid electricalshock, do not perform any servicingunless you are
qualified to do
so.
The openingof covers orremoval of parts is likely toexpose
dangerousvoltages. Disconnect the product from
all voltage sources
while it isbeing opened.
The power cord is connected to internal capacitors that my remain
livefor
5 secondsafter disconnecting the plugfrom itspower supply.
For Continuedprotection against firehazard, replacetheline fuse(s)
only with
250 V fuse(s)orthe same currentrating andtype (for
example, normal blow
or time delay).Do not use repaired fuses or
shortcircuited fuseholders.
Always use the three-prong ac power cord suppliedwith this
product. Failureto ensureadequate earthgroundingby not using
this cord may causeproduct damage.
Thisproduct is designed for use inInstallation Category I1 and
Pollution Degree
2 per ZEC 1010 and ZEC 664 respectively. FOR
INDOOR
USE ONLY.
Thisproduct has autorangingline voltage input, be surethe supply
voltage
is within the specifiedrange.
Chapter 1 3

RegulatoryInformation(UpdatedMarch 1999)
To prevent electrical shock,disconnectinstrument from mains (line)
before cleaning.Use a drycloth or one slightlydampenedwith water
to cleanthe external caseparts. Do not attempt to clean internally.
VentilationRequirements: When installingthe product in a cabinet,
the convectioninto and out of theproduct must not be restricted.
The ambienttemperature (outsidethe cabinet)must belessthan the
maximum operatingtemperatureof theproduct by
4" C for every 100
watts dissipated in the cabinet. If the total power dissipatedin the
cabinet is greaterthan
800 watts, then forced convection must be
used.
Product Markings
CE - the CE mark is a registered trademark of the European Community. A CE mark
accompaniedby a year indicated the year the design was proven.
CSA - the CSA mark is a registered trademark of the Canadian StandardsAssociation.
4 Chapter 1

Model 8901B Service
SAFETY CONSIDERATIONS
GENERAL
This product and related documentation must be re-
viewed for familiarization with safety markings and
instructions before operation.
This product is a Safety Class I instrument (provided
with a protective earth terminal).
BEFORE APPLYING POWER
Verify that the product is set to match the available
line voltage and the correct fuse is installed.
SAFETY EARTH GROUND
An uninterruptible safety earth ground must be pro-
vided from the main power sourceto theproduct input
wiring terminals, power cord,
or supplied power cord
set.
SAFETY SYMBOLS
Instruction manual symbol: the product will
A be marked with this symbol when it
is necessary for the user to refer to the instruction
manual (refer to Table of Contents).
Indicates hazardous voltages.
Indicates earth (ground) terminal.
The WARNING sign denotes a
hazard. It calls attention to a
procedure, practice,
or the like, which, if not correctly
performed
or adhered to, could result in personal in-
jury.
Do not proceed beyond a WARNING sign until
the indicated conditionsarefully understoodand met.
The CAUTION sign denotesa haz-
ard.
It calls attention to an
operatingprocedure,practice, or the like, which, if not
correctlyperformed
or adhered to,could result in dam-
age
to or destruction of part or all of the product. Do
not proceed beyond a CAUTION sign until the indi-
cated conditions are fully understood and met.
I WARNING
Any interruption of the protective (ground-
ing) conductor (inside
or outside the instru-
ment)
or disconnecting the protective earth
terminal will cause a potential shock hazard
that could result in personal injury. (Ground-
ing one conductor of a two conductor outlet
is not sufficientprotection).
Whenever it is likely that the protection has
been impaired, the instrument must be made
inoperative and be secured against any unin-
tended operation.
If this instrument is to be energized via an
autotransformer(for voltage reduction) make
sure the common terminal is connected to the
earth terminal of the power source.
Servicing instructions are for use by service-
trained personnel only.
To avoid dangerous
electric shock,
do not perform any servicing
unless qualified to do
so.
Adjustments described in the manual are per-
formed withpower supplied to the instrument
while protective covers are removed. Energy
available at manypoints may,
if contacted, re-
sult
in personal injury.
Capacitors inside the instrument may still be
charged even if the instrument has been dis-
connected from its source of supply.
For continued protection against fire hazard,
replace the line fuse(s) only with
250V fuse(s)
ofthe same current rating and type (forexam-
ple, normal blow, time delay, etc.).
Do not use
repaired fuses
or short circuited
fuseholders.

ATTENTION
Static Sensitive
Devices
This instrument was constructed in anESD (electro-static discharge)
protected environment. This
is because most of the semi-conductor
devices used
in this instrument are susceptible to damage by static
discharge.
Depending on the magnitude of the charge, device substrates can be
punctured
or destroyed by contact or mereproximity ofa static charge.
Theresults can cause degradationofdeviceperformance,earlyfailure,
or immediate destruction.
Thesecharges aregenerated in numerous ways such as simple contact,
separation of materials, and normal motions ofpersons working with
static sensitive devices.
When handling or servicing equipment containing static sensitive
devices, adequate precautions
must be taken toprevent device damage
or destruction.
Only those who are thoroughly familiar with industry accepted
techniques for handling static sensitive devices should attempt to
service circuitry with these devices.
In all instances, measures must be taken to prevent static charge
build-up on work surfacesand persons handling the devices.

Model 8901B Volume
1 Table of Contents
VOLUME 1
TABLE OF CONTENTS
SECTION 6
REPLACEABLE PARTS
Introduction To This Section ........................................... 6-1
Reference Designators and Abbreviations
.................................... 6-1
Replaceable Parts List .............................................. 6-1
OrderingParts ................................................ 6-1
Replaceable
Parts List Updating (Manual Updates) ..............................
6-2
Mechanical and Chassis
Part Locationsand Reference Designations .................... 6-2
RecommendedSparesList
............................................ 6-2
SECTION 7
INSTRUMENT CHANGES
Introduction to This Section ........................................... 7-1
Firmware Change
Summary (23l4A to 2644A) ................................. 7-1
SECTION 8
SERVICE
Introduction to This Section .......................................... 8A-1
How This Sectionis Organized ......................................... 8A-1
Safety Considerations
.............................................. 8A-2
Before Applying Power .......................................... 8A-2
Safety
.................................................... 8A-2
Service
Tools and Aids ............................................. 8A-3
ServiceAccessory Kit
........................................... 8A-3
Heat-Staking
Tool ............................................. 8A-4
Assembly Locations
............................................ 8A-4
Parts and Cable Locations ........................................ 8A-5
Other Service Documents
......................................... 8A-5
RecommendedTest Equipment
and Accessories ............................ 8A-5
General Troubleshooting
............................................ 8A-5
OperatorErrors
.............................................. 8A-5
OperationOut
of Specifcation ...................................... 8A-5
CatastrophicFailures
........................................... 8A-6
Schematic Symbology and SchematicDiagram Notes
............................ 8A-10
SpecialFunctions
................................................ .8B-1
General
.................................................... 8B-1
Direct Control SpecialFunctions(Prefix
0) ..................... : ......... .8 B-1
Service SpecialFunctions (Prefm 40-99)
................................ .8B-5
rev.08JUL91

Volume 1 Table of Contents
~
Model 8901B
SECTION 8
SERVICE (cont’d)
Error Messages ................................................. 8B-14
General
................................................... 8B-14
Error Message Catagories
........................................ 8B-14
EnablingMeasurement Progress
and Service ErrorMessages .................... 8B-14
Measurement Progress ErrorMessages(Errors
40 through64) .................... 8B-14
Service ErrorMessages (Errors
65 through89) ............................. 8B-15
Power-UpChecks
................................................ 8B-17
Controller Test LEDs and Test Points
..................................... 8B-18
Signature Analysis
............................................... 8B-19
General Disassembly Procedures
....................................... .8 C-1
Top Cover Removal ............................................ .8 C-1
Bottom Cover Removal .......................................... .8 C-1
Side Cover Removal ............................................
.8 C-1
Wormation Tray Removal
........................................ .8 C-1
Front PanelDisassembly Procedure ...................................... .8 C-1
Front-PanelAssembly Removal ..................................... .8 C-1
A1Keyboard andDisplay Assembly Removal ............................. .8 C-2
Front Dress Panel and Display Window Removal
........................... .8 C-2
Replacement of PushbuttonSwitches and Annunciator LEDs .................... .8 C-2
Service SheetBD1-Overall Block Diagram ................................. 8D-1
Service SheetBD2-RF Block Diagram
.................................... 8D-15
Service SheetBD3-IF Block Diagram
.................................... 8D-25
Service SheetBD4-Audio Block Diagram
.................................. 8D-37
Service Sheet BD5-Digital and Power SupplyBlock Diagram ....................... 8D-47
Block Diagram Foldouts ............................................ .8 E.l
rev.08JUL91

Model 8901B Replaceable Parts
Section 6
REPLACEABLE PARTS
6-1. INTRODUCTIONTO THIS SECTION
This section contains information for ordering parts. Table 6-1 lists reference designations, and
Table
6-2 lists abbreviations that are used in the Replaceable Parts List. Table 6-3 lists all replaceable
parts in the instrument. Table
6-4 contains the names and addresses that correspond to the
manufacturer’s code numbers listed in Table
6-3. Also included in this section are photographs and
drawings
to aid in identifying and ordering chassis mounted parts and mechanical parts.
6-2. REFERENCE DESIGNATIONSAND ABBREVIATIONS USED IN THIS MANUAL
Table 6-1 lists the reference designation letters for electrical parts in the instrument. The letter
designations found in Table
6-1 are coupled with numeric designationsto provide a unique reference
designation for each part in the instrument.
For example A17R1 is the reference designation of a
particular resistor
R1 on assembly A17.
Table 6-2 lists abbreviations used in the parts list and on schematics.
6-3. REPLACEABLE PARTS LIST
Table 6-3 is a list of replaceable parts and is organized as follows:
a. Electrical assemblies and their componentswith reference designationsin alphanumeric order.
b. Chassis-Mountedparts with reference designationsin alphanumericorder.
c. Mechanicalparts with reference designations in alphanumeric order.
For your convenience, the Replaceable Parts List is paginated so that each assembly listing can be
removed from Section
6 and collated into Section 8 with its corresponding service information.
Ordering Parts.
instrument Serial Numbers.
Attached to the rear of the instrument is a serial-numberplate. The first four digits and the letter
are the instrument serial-number prefix. The last five digits (serial-numbersuffix) are unique to each
instrument. When parts in the instrument are changed, the serial-numberprefix of the instrument may
also change. This means that sometimes a part will be listed more than once in the the replaceable
parts list along with a serial-number prefix
or range of serial-numberprefixes. Find the serial-number
prefix on the serial plate of your instrument and order the part listed under the correspondingprefix
in the table. If no serial prefix information is listed, the part is compatible
in instruments of all serial
numbers.
NOTE
It is possible that some assemblies in your instrument have been updated
(throughservice
or retrofitting)to reflectchanges made to instruments with
serial-number prefixes later than that shown on your instrument serial-
number tag.Be sure to note the board number
of the assembly being repaired
or replaced when ordering parts for your instrument.
6- 1