Seagate ST43401N/ND User manual

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Elite Disc Drive
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ST43401N/ND
○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○
ST43402ND
○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○
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Reference Manual
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Contents
Preface ................................................................................................... iii
Electrostatic discharge protection........................................................... iii
Important safety information and precautions ......................................... iv
Technical support services ..................................................................... vi
Section 1. General maintenance information ......................................... 1
Section 2. Planning the system.............................................................. 5
Section 3. Interface functions ................................................................ 19
© 1994 Seagate Technology, Inc. All rights reserved
Publication number: 83327730, Rev. C
December 1994
Seagate®, Seagate Technology®, and the Seagate logo are registered
trademarks of Seagate Technology, Inc. Elite™, SeaFAX™, SeaFONE™,
SeaTDD™, and SeaBOARD™ are trademarks of Seagate Technology, Inc.
Other product names are registered trademarks or trademarks of their
owners.
Seagate reserves the right to change, without notice, product offerings or
specifications. No part of this publication may be reproduced in any form
without written permission from Seagate Technology, Inc.

ST43401N/ND and ST43402ND Reference Manual, Rev. C iii
Preface
This is a reference manual for users of Seagate®ST43401N/ND and
ST43402NDElite™discdrivesemployingtheSCSIinterface.Itsupplements
the information presented in the user’s manual (publication 83327720). It is
intended to aid engineers who design subsystems using the drive and
customer engineers who install and check out the drive. This manual should
be used in conjunction with the user’s manual.
Electrostatic discharge protection
Caution. Removalofcircuitboardsbypersonnelnotperformingdepotrepair
will damage components and may void the warranty.
All drive electronic assemblies are sensitive to static electricity due to the
electrostatically sensitive devices used within the drive circuitry. Although
some devices such as metal-oxide semiconductors are extremely sensitive,
all semiconductors, as well as some resistors and capacitors, may be
damaged or degraded by exposure to static electricity.
Electrostatic damage to electronic devices may be caused by the direct
dischargeofachargedconductor,orbyexposuretothestaticfieldssurround-
ingchargedobjects.Toavoiddamagingdriveelectronicassemblies, service
personnel must observe the following precautions when servicing the drive:
• Ground yourself to the drive whenever the drive electronics are or will be
exposed. Connect yourself to ground with a wrist strap (Seagate part
number 12263496). Connection may be made to any grounded metal
assembly. As a general rule, remember that you and the drive electronics
must all be grounded to avoid potentially damaging static discharges.
• Turn off power before removing or installing the DC power cable.
• Do not remove any circuit boards from the drive.
• Never use an ohmmeter on any circuit boards.

iv ST43401N/ND and ST43402ND Reference Manual, Rev. C
Important safety information and precautions
Caution. Use forced-air ventilation when bench-testing the drive to ensure
proper cooling of drive components.
Usepropersafetyandrepairtechniquesforsafe,reliableoperationofthisunit.
Service should be done only by qualified persons. We recommend the
procedures in this manual as effective ways of servicing the unit. Some
procedures require the use of special tools. For proper maintenance and
safety, you must use these tools as recommended.
The procedures in this manual contain warnings and cautions that must be
carefullyreadandfollowedtominimizeoreliminatetheriskofpersonalinjury.
The warnings point out conditions or practices that may endanger you or
others. The cautions point out conditions or practices that may damage the
unit, possibly making it unsafe for use.
Youmustalso understand that these warnings andcautionsare not exhaus-
tive. We cannot possibly know, evaluate, and advise you of all the ways in
whichmaintenancemightbeperformedorthepossibleriskofeachtechnique.
Consequently,wehavenotcompletedanysuchbroadevaluation.Ifyouuse
anon-approvedprocedureortool,firstensurethatthemethodyouchoosewill
not risk either your safety or unit performance.
Always observe the following warnings and precautions:
• Perform all maintenance by following the procedures in this manual.
• Follow all cautions and warnings in the procedures.
• Use sound safety practices when operating or repairing the unit.
• Usecautionwhentroubleshootingaunitthathasvoltagespresent.Remove
power from the unit before servicing it.
• Wear safety shoes when removing or replacing heavy parts.
• Ensure that the internal temperature of the rack or cabinet will not exceed
the limits defined for the drive when the drive is mounted in an equipment
rack or cabinet. When units are stacked vertically, pay special attention to
the top where temperatures are usually highest.
• Follow the precautions listed under “Electrostatic discharge protection”
above.

ST43401N/ND and ST43402ND Reference Manual, Rev. C v
• Do not remove any circuit boards from the drive chassis. Return the entire
drive for depot repair if any circuit board is defective. Removal of circuit
boardsbypersonnelnotperforming depot repair will damage components
and may void the warranty.
• Do not remove the head and disc assembly (HDA) from the drive chassis.
Return the entire drive for depot repair if the HDA is defective.
• DonotattempttodisassembletheHDA.Itisnotfieldrepairable.Ifthesealed
HDA is opened by personnel not performing depot repair, this will damage
components and void the warranty.
• As a component, this drive is designed to be installed and operated in
accordancewithUL1950,IEC950,EN60950,CSAC22.2950,andVDE0805.
Refer to Section 2 for information about installation.
• Ensure that the power supply meets the specifications in this manual and
isdesignedtobeusedinaccordancewithUL1950,IEC950,EN60950,CSA
C22.2 950, and VDE0805.
Seagate takes all reasonable steps to ensure that its products are certifiable
to currently accepted standards. Typical applications of these disc drives
include customer packaging and subsystem design. Safety agencies condi-
tionally certify component assemblies, such as the Elite disc drive, based on
theirfinalacceptabilityinthe end-use product.Thesubsystemdesignersare
responsible for meeting these conditions of acceptability in obtaining safety/
regulatory agency compliance in their end-use products and in certifying
whererequiredbylaw.Anecessarypartofmeetingsafetyrequirementsisthe
provision for overcurrent protection on drive SELV supply voltages.
This unit is a component part and as such is not meant to comply with FCC
or similar national requirements as a stand-alone unit. Engineering radiated
and conducted emissions test results are available through the Seagate
Safety Department to assist the subsystem designer.

vi ST43401N/ND and ST43402ND Reference Manual, Rev. C
Technical support services
Seagate Technology provides technical support literature and diagnostic
utilities to authorized distributors. Please contact your dealer for technical
support and installation troubleshooting. Product technical support is avail-
able for all Seagate products by calling the SeaFAX™, SeaFONE™,
SeaTDD™, or SeaBOARD™ services. These are toll calls if you dial from
outside of the number’s local dialing area.
SeaFAX:
USA [phone]; England 44-62-847-7080
Useatouch-tonetelephonetoaccessSeagate’sautomatedFAXsystemand
select technical support information by return FAX. This service is available
24 hours a day, 7 days a week.
SeaFONE: [phone]
Technical support specialists are available from 8:00 A.M. to 5:00 P.M. PST,
MondaythroughFriday.RecordedtechnicalinformationforselectedSeagate
products is accessible 24 hours a day, 7 days a week.
SeaTDD: [phone]
TDD is a telecommunication device for the deaf where two people can
communicateusingakeyboardconnectedtothephoneline.ATDDdeviceis
required to access this service, which is available from 8:00A.M. to 5:00 P.M.
PST, Monday through Friday.
SeaBOARD:
TheSeagateTechnicalSupportBulletinBoardSystem(BBS)isavailable24
hoursa day, 7 days a week.A modem is required toaccess this service. The
communicationssoftwaremustbesetfor8databits,noparity, and 1 stop bit
(8N1).AllBBSnumbersoperateat9600baudmax.Withthisserviceyoucan
access:
• Specifications and jumper configurations for Seagate products
• Reprints of Seagate documentation
• Adirectoryofinformationandhelpful utilities that you candownloadtoyour
computer

ST43401N/ND and ST43402ND Reference Manual, Rev. C vii
Location Telephone number
USA, Mexico, Latin America [phone]
England 44-62-847-8011
Germany 49-89-140-9331
Singapore 65-292-6973
Australia 61-2-756-2359
Canada [phone]
France 33-1-40-67-1034
Korea 82-2-556-7294

ST43401N/ND and ST43402ND Reference Manual, Rev. C 1
Section 1. General maintenance information
This section contains general information relating to maintenance of the
drive.Youshouldbefamiliarwiththeinformationinthissectionandwithdrive
operation before attempting any maintenance procedures. Information is
divided into the following areas:
• Maintenance tools and materials—lists the tools and materials required to
perform maintenance on the drive
• Testing the drive—provides information concerning testing drive electron-
ics, including a procedure for checking DC voltages supplied to the drive
• Identifyingassembliesinthe drive—identifies thevariouspartsofthedrive
Note. Refer to the user’s manual (publication 83327720) for information
about arranging for depot repair, removing and replacing a drive or
power supply, and packing a drive for shipment.
Maintenance tools and materials
The procedures described in this section require the use of certain special
tools, test equipment, and materials. These are listed below along with the
Seagatepartnumber.Notethatthelistincludesonlyspecialtools.Weassume
that you have normal maintenance tools.
Description Seagate part number
Static ground wrist strap 12263496
6 1/2 to 8 inch wrist
Volt/ohmmeter Ballantine 345 or equivalent digital voltmeter
Testing the drive
During testing and troubleshooting, the drive normally performs various
operations such as reading and writing test data. System software can be
used to control the drive during these operations. Refer to manuals or other
documentationapplicabletothespecificsystemorsubsystemforinformation
concerning the system software routines.
The drive also has built-in diagnostic tests. These diagnostic tests may be
performed through the interface as described in Section 3.

DC
Power
Cable
Insert
Probe
Here
DC Power
Connector
J15
+12 V
Pin 1 +12 V
Return
Pin 2 +5 V
Return
Pin 3
+5 V
Pin 4
2 ST43401N/ND and ST43402ND Reference Manual, Rev. C
The following procedure provides an overall check of the DC voltages used
bythedrive.Beforeperformingthisprocedure,youshouldbefamiliarwiththe
other information in this section and the safety information in the preface.
Theillustrationtotherightshowswhere
the individual voltages appear on the
drive’s DC power connector (J15).
Insert your test probe into the contact
openings on the back surface of the 4-
pin DC cable connector.
1. Using system software, command
continuous read/write operations
with the drive on a single cylinder.
2. Connect the voltmeter ground lead
toJ15-Pin3(+5VReturn[Ground]).
3. Measure at the appropriate connec-
tion point to check the following
voltages:
Voltage Connection Specification
+5.0 volts J15 - Pin 4 +4.75 to +5.25 volts
+12 volts J15 - Pin 1 +11.4 to +12.6 volts
Identifying assemblies in the drive
Thedrive’smajorassembliesandcomponentsareshowninFigures1and2.
Thecomponentsaresupportedbyachassis,andtheheadanddiscassembly
(HDA) is supported by shock mounts attached to the chassis. The control
board is mounted above the HDA. The power board has a right-angle
connection to one end of the control board. An optional bezel is available.

ST43401N/ND and ST43402ND Reference Manual, Rev. C 3
Control
Board Power
Board
Optional
Bezel
Chassis
DC Power
Connector
Option Jumpers and
Spindle Sync
Connector
Option
Jumpers
I/O
Connector
Option
Jumpers
Option
Jumpers
Head and Disc
Assembly (HDA)
Pin 1
Figure 1. ST43401N/ND drive components

4 ST43401N/ND and ST43402ND Reference Manual, Rev. C
Control
Board
Chassis
Head and Disc
Assembly (HDA)
Power
Board
DC Power
Connector
Option
Jumpers
Pin 1
I/O
Board
Optional
Bezel
Spindle Sync
Connector
Remote Operator
Panel Connector
Port B
I/O Connector
Port A
I/O Connector
Port A
Terminator
Power
Port B
Terminator
Power Option
Jumpers
I/O Board
Power
Figure 2. ST43402ND drive components

ST43401N/ND and ST43402ND Reference Manual, Rev. C 5
Section 2. Planning the system
Thissectionsupplementsthe installationinstructionspresentedintheuser’s
manual (publication 83327720). To aid in configuring the drive for specific
system requirements, the following subjects are discussed:
• Guidelines for enclosure design
• Guidelines for proper air flow
• Guidelines for I/O cabling
• Using the sweep cycle function
Guidelines for enclosure design
The drive is a component for installation in an enclosure that you have
designed. The enclosure design must provide for mounting the drive and
powersupply,cablerouting,andcooling.Seethenexttopicforguidelineson
providing proper cooling.
Thesystemdesignerisresponsibleforobtaininganyneededagencyapprov-
als such as UL, CSA, and VDE.
Figure 3 provides mounting dimensions for ST43401N/ND and ST43402ND
driveswithoutabezel.Figure4providesthesameinformationforST43401N/
NDdriveswiththeoptionalbezelattached.Asdescribedintheuser’smanual,
the drive can be mounted using either side-mounting screws or bottom-
mounting screws.

6 ST43401N/ND and ST43402ND Reference Manual, Rev. C
K
M4 x .70 Metric Threads (4)
B
C
D
E
FJ
C.G.
L
6-32 Threads (4)
C.G.
I
I
GH
A
Side
A
B
C
D
E
F
G
H
I
J
K
L
3.25
0.86
0.39
1.93
3.120
8.60
5.50
5.75
0.12
3.96
1.58
3.13
0.01
0.01
0.01
0.01
0.005
0.03
0.01
0.01
0.01
0.05
0.05
0.05
±
±
±
±
±
±
±
±
±
±
±
±

82.55
21.84
9.91
49.02
79.25
218.44
139.70
146.05
3.05
100.58
40.13
79.50
in mm
Bottom
6-32 Threads (4)
Figure 3. Mounting dimensions for ST43401N/ND and ST43402ND drives
without a bezel

ST43401N/ND and ST43402ND Reference Manual, Rev. C 7
6-32 Threads (4)
D
E
F
C.G.
6-32 Threads (4)
C.G.
Side
Bottom
M4 x .70 Metric Threads (4)
A
B
C
K
O
N
I
PHG
J
L
M
in mm
A
B
C
D
E
F
G
3.25
0.86
0.39
1.87
3.120
8.00
5.50
0.01
0.01
0.01
0.02
0.005
max0.01
±
±
±
±
±
±
H
I
J
K
L
M
N
O
P
5.75
0.12
0.06
3.38
5.88
0.19
3.90
1.58
3.13
0.01
0.01
0.02
0.02
0.01
0.01
0.05
0.05
0.05
146.05
3.05
1.52
85.85
149.35
4.83
99.06
40.13
79.50
±
±
±
±
±
±
±
±
±
in mm
82.55
21.84
9.91
47.50
79.24
203.20
139.70
Figure 4. Mounting dimensions for ST43401N/ND with a bezel

8 ST43401N/ND and ST43402ND Reference Manual, Rev. C
Guidelines for proper air flow
Your enclosure design must ensure adequate cooling for the drive.
Werecommendorientingthedriveordirectingtheairflowinawaythatcreates
theleastamountofair-flowresistancewhileprovidingairflowabovethecircuit
boards and around the head and disc assembly (HDA). Also, choose the
shortest possible path between the air inlet and exit. This minimizes the
distance traveled by air that is heated by the drive and by other nearby heat
sources.
Figure5showsthedesignapproach with one or morefansinstalled.Theair-
flow patterns can be created by the fans either pushing or drawing air. The
overall flow pattern can be directed from front to back, back to front, or side
to side.

ST43401N/ND and ST43402ND Reference Manual, Rev. C 9
Above unit
Under unit
Note. Air flows in the direction shown (front to back)
or in reverse direction (back to front)
Above unit
Under unit
Note. Air flows in the direction shown or
in reverse direction (side to side)
Figure 5. Suggested air flow

10 ST43401N/ND and ST43402ND Reference Manual, Rev. C
Toevaluatetheair-flowdesign,placethedriveinitsfinalmechanicalposition
and perform random read and write operations. After the temperatures
stabilize,measurethe surface(case)temperaturesof thecomponentslisted
in the appropriate table below. The mean time between failures (MTBF)
values assume that the drive operates below the specified reliability guide-
lines.
Table 1. ST43401N/ND air-flow evaluation
Office Computer
environment room
MTBF MTBF Max
200k hours 300k hours allowable
Card Component Reference case temp* case temp* case temp*
S/RYFX PERI-2 D540 45 35 60
S/RYFX Video AMP F826 55 45 70
S/RYFX RDS G115 55 45 70
S/RYFX ECLTTL D212 47 37 62
S/RYFX SCRAM C051 44 34 59
S/RYFX DRAM B405 42 32 57
FYEX Motor control U10(A211) 51 41 66
HDA housing Figure 6 60
*Temperature in oC
Table 2. ST43402ND air-flow evaluation
Office Computer
environment room
MTBF MTBF Max
200k hours 300k hours allowable
Card Component Reference case temp* case temp* case temp*
AYGX PERI-2 U40 (D540) 45 35 60
AYGX Video AMP U44 (F826) 52 42 67
AYGX RDS U56 (G115) 56 46 71
AYGX ECLTTL U33 (D709) 46 36 61
AYGX SCRAM U6 (B145) 45 35 60
AYGX Driver U26 (B107) 45 35 60
FYEX Motor control U10 (A211) 49 39 64
BYGX ECLTTL U7 (D417) 52 42 67
HDA housing Figure 6 60
*Temperature in oC

ST43401N/ND and ST43402ND Reference Manual, Rev. C 11
Guidelines for I/O cabling
This topic provides recommendations for I/O cabling and lists the parts that
can be used in various cables. There are three general cabling schemes, as
illustrated in the following figures:
• Figure7describeshowtodesigncableswhentheinitiatorandallthedrives
are located in one cabinet
• Figure8describes howtodesigncableswhentheinitiatorislocatedinone
cabinet and all the drives are located in another cabinet
• Figure 9 describes how to design cables when the initiators and drives are
distributed within three cabinets
Refertotheappropriatefiguretodeterminethetypesofcomponentsrequired
for your installation. All three figures show how drives inside a cabinet are
connected by continuous unshielded I/O cables that have a connector for
each drive. In some cases, these internal cables connect to a bulkhead that
allows external shielded cables to be connected. Shielded cables must be
used if the cables run between cabinets.
Cumulative cable length in a daisy-chain system cannot exceed 25.0m
(82.0 ft) for drives using differential I/O. With single-ended I/O, cumulative
cable length cannot exceed 3.05m (10.0 ft).
1.75
4.81
Figure 6. Temperature measurement location on the HDA (bottom)

12 ST43401N/ND and ST43402ND Reference Manual, Rev. C
Drives and initiator in one cabinet
Drive
0
Drive
N
Initiator
Terminator
2 x 34 Pin
Connector
68 Conductor
Flat Cable or
Twisted Pair
Terminator
Notes:
1. Cables and terminators shown are unshielded.
2. Flat cable can be used with single-ended drivers.
Twisted-pairflatcablemustbeusedwithdifferential
drivers.
3. Totallengthofcablesandstubscannotexceed25m
(82.0 ft) with differential drivers or 3.05m (10.0 ft)
with single-ended drivers.
Figure 7. Cabling with one cabinet