Seagate BARRACUDA 2LP ST31250N/ND User manual

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BARRACUDA 2LP
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Disc Drive
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ST31250N/ND
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ST31250W/WD/WC/DC
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ST32550N/ND
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ST32550W/WD/WC/DC
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Installation Guide
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Contents
Preface .................................................................. 1
Electrostatic discharge protection ........................... 1
Important safety information and precautions ......... 2
WichtigeSicherheitshinweise............................... 5
Technical support services ..................................... 10
General description ................................................ 13
Initial setup information ........................................... 19
Kühlung des Systems .......................................... 24
© 1995 Seagate Technology, Inc. All rights reserved
Publication Number: 83328920, Rev. E
October1995
Seagate®, SeagateTechnology®, and the Seagatelogo
are registered trademarks of SeagateTechnology, Inc.
Barracuda™,SeaFAX™,SeaFONE™,SeaTDD™,and
SeaBOARD™ are trademarks of Seagate Technology,
Inc. Other product names areregistered trademarks or
trademarks of their owners.
No part of this publication may be reproduced in any
formwithout writtenpermissionfrom SeagateTechnol-
ogy, Inc.

Barracuda 2LP Installation Guide, Rev. E 1
Preface
This manual contains information for users of the
Seagate®ST31250andST32550Barracuda™2LPSCSI
disc drives. It provides support services, performance
specifications, and initial setup information. Additional
information is available in the Barracuda 2LP Product
Manual (partnumber83328930).ContactyourSeagate
sales representative if you need to order this publica-
tion.
Electrostatic discharge protection
Caution. Removal of circuit boards by personnel not
performing depot repair will damage compo-
nents and may void the warranty.
All drive electronic assemblies are sensitive to static
electricity,dueto theelectrostaticallysensitivedevices
used within the drive circuitry. Although some devices
such as metal-oxide semiconductors are extremely
sensitive,allsemiconductors,aswellassomeresistors
andcapacitors,maybedamagedordegradedbyexpo-
sure to static electricity.
Electrostatic damage to electronic devices may be
causedbythedirectdischargeofachargedconductoror
by exposure to the static fields surrounding charged
objects.Toavoiddamagingdriveelectronicassemblies,
observe the following precautions when installing or
servicing the drive:

2 Barracuda 2LP Installation Guide, Rev. E
• Ground yourself to the drive whenever the drive elec-
tronics are or will be exposed. Connect yourself to
ground with a wrist strap (Seagate part number
12263496).Connectionmaybemadetoanygrounded
metal assembly. As a general rule, remember that you
andthe driveelectronicsmust allbe groundedtoavoid
potentially damaging static discharges.
• Turnoffthepowerbeforeremovingorinstallingthe DC
power cable.
• Do not remove any circuit boards from the drive.
• Never use an ohmmeter on any circuit boards.
• Wheninstalling thedriveon acarrier ortray,discharge
the static electricity from the carrier or tray prior to
inserting it into the system.
Important safety information and precautions
Caution. Useforced-air ventilationwhen bench-testing
the drive to ensure proper cooling of drive
components.
Usepropersafetyandrepairtechniquesforsafe,reliable
operation of this unit. Service should be done only by
qualifiedpersons.Werecommendtheproceduresinthis
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.

Barracuda 2LP Installation Guide, Rev. E 3
The procedures in this manual and labels on the unit
contain warnings and cautions that must be carefully
read and followed to minimize or eliminate the risk of
personal injury. The warnings point out conditions or
practicesthatmayendangeryouorothers.Thecautions
point out conditions or practices that may damage the
unit, possibly making it unsafe for use.
These warnings and cautions are not exhaustive. We
cannotpossiblyknow,evaluate,andadviseyouofallthe
ways in which maintenance might be performed or the
possible risk of each technique. Consequently, we have
not completed any such broad evaluation. If you use a
non-approved procedure or tool, first ensure that the
methodyou choose willnot risk eitheryour safety orunit
performance.
Alwaysobservethefollowingwarningsandprecautions:
• Performallmaintenancebyfollowingtheproceduresin
this manual.
• Follow all cautions and warnings in the procedures.
• Usesoundsafetypracticeswhenoperatingorrepairing
the unit.
• Use caution when troubleshooting a unit that has
voltages present. Turn off power to the unit before
servicing it.
• Wear safety shoes when removing or replacing heavy
parts.

• Ensure that the internal temperature of the rack or
cabinetdoes notexceedthe limitsdefined forthe 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 above in “Electrostatic
discharge protection.”
• Do not remove any circuit boards from the drive chas-
sis.Return theentire drivefordepot repairif anycircuit
boardisdefective.Removalofcircuitboardsbyperson-
nel not performing depot repair will damage compo-
nents and may void the warranty.
• Donotremovetheheadanddiscassembly(HDA)from
thedrivechassis.Returntheentiredrivefordepotrepair
if the HDA is defective.
• Do not attempt to disassemble the HDA. It is not field
repairable. If the sealed HDA is opened by personnel
not performing depot repair, this will damage compo-
nents and void the warranty.
Asacomponent,thisdriveisdesignedtobeinstalledand
operatedinaccordancewithUL1950,IEC950,EN60950,
CSA C22.2 950, and VDE0805.
Seagate takes all reasonable steps to ensure that its
productsare certifiable tocurrently acceptedstandards.
4 Barracuda 2LP Installation Guide, Rev. E

Typical applications of these disc drives include cus-
tomer packaging and subsystem design. Safety agen-
ciesconditionallycertifycomponentassemblies,suchas
theBarracudadiscdrive, basedontheirfinalacceptabil-
ityintheend-useproduct. Thesubsystemdesignersare
responsibleformeetingtheseconditionsofacceptability
inobtainingsafety/regulatoryagencycomplianceintheir
end-use products and for certifying where required by
law. A necessary part of meeting safetyrequirements is
the provision for overcurrent protection on drive SELV
supply voltages.
Thisunitisacomponentpartandassuchisnotmeantto
comply with FCC or similar national requirements as a
stand-alone unit. Engineering radiated emissions test
resultsareavailablethroughtheSeagateSafetyDepart-
ment to assist the subsystem designer.
WichtigeSicherheitshinweise
Vorsicht.BeimTestendesLaufwerksaufdemPrüftisch
ist Fremdbelüftung vorzusehen, um eine ausreichende
Kühlung der Laufwerkkomponenten sicherzustellen.
Verwenden Sie geeignete Sicherheits- und
Reparaturverfahren, um den sicheren, zuverlässigen
Betrieb dieser Einheit zu gewährleisten. Reparaturen
dürfennurvonqualifiziertemFachpersonalvorgenommen
Barracuda 2LP Installation Guide, Rev. E 5

werden.WirempfehlendieVerfahrenindiesemHandbuch
als effektive Methoden zur Wartung und Reparatur der
Einheit. Einige Verfahren erfordern Spezialwerkzeuge;
diese müssen zur sachgemäßen Ausführung der
Wartungsarbeiten und aus Sicherheitsgründen den
Empfehlungen entsprechend verwendet werden.
DieVerfahrenindiesemHandbuchunddieAufkleberauf
demGerätenthaltenWarn-undVorsichtshinweise.Diese
Hinweisesind sorgfältigdurchzulesen undzubeachten,
um das Risiko von Verletzungen auf ein Mindestmaß zu
beschränkenoderganzzuvermeiden.DieWarnhinweise
machenaufSituationenoderPraktikenaufmerksam,die
Sie oder andere gefährden könnten. Die
VorsichtshinweisemachenaufSituationenoderPraktiken
aufmerksam, die die Einheit beschädigen können, so
daß deren Gebrauch mit Risiko behaftet ist.
Die Warn- und Vorsichtshinweise sind nicht
allumfassend! Es ist uns einfach nicht möglich, alle
WartungsmethodenoderdieeventuellenRisikenjeder
Methode zu kennen, zu beurteilen und Sie
entsprechend zu beraten. Aus diesem Grund haben
wir auf eine derartige umfassende Beurteilung
verzichtet. Falls Sie ein hier nicht beschriebenes
Verfahren oder Werkzeug verwenden, stellen Sie
zuerstsicher,daßdas gewählteVerfahrenwederIhre
6 Barracuda 2LP Installation Guide, Rev. E

persönliche Sicherheit noch die Leistung der Einheit
gefährdet.
Beachten Sie in jedem Fall die folgenden Warn-und
Vorsichtshinweise:
• Führen Sie alle Wartungsarbeiten entsprechend den
Anweisungen in diesem Handbuch aus.
• Beachten Sie alle Warn- und Vorsichtshinweise in
diesem Handbuch.
• Treffen Sie beim Betrieb oder bei der Reparatur der
Einheitangemessene Sicherheitsvorkehrungen.
• WenneineEinheitunterSpannungsteht,gehenSiebei
derFehlerdiagnosebesondersvorsichtigvor.Schalten
SiedieEinheitaus,bevorSiemitdenReparaturarbeiten
beginnen.
• TragenSieSicherheitsschuhe,wennSieschwereTeile
aus- bzw. einbauen.
• Wenn das Laufwerk in einem Einbaugestell oder
Gehäuse montiert ist, sorgen Sie dafür, daß die
Temperatur im Inneren des Gestells oder Gehäuses
die für das Laufwerk vorgegebenen Grenzwerte nicht
übersteigt. Wenn Einheiten vertikal übereinander
betestigtwerden,achtenSiebesondersaufdenoberen
Stapelbereich, da dort die Temperatur gewöhnlich am
höchsten ist.
Barracuda 2LP Installation Guide, Rev. E 7

• Befolgen Sie die oben unter “Electrostatic Discharge
Protection”angegebenenSicherheitsmaßnahmen.
• NehmenSiekeinePlatinenausdemLaufwerkgehäuse.
WenneinePlatinedefektist,mußdasgesamteLaufwerk
zurReparatureingeschickt werden.DieHerausnahme
von Platinen durch anderePersonen als die für die
werkseitige Reparatur zuständigen kann zu einer
Beschädigung der Komponenten und Erlöschen des
Garantieanspruchsführen.
• Die vormontierte Kopf- und Festplatteneinheit (HDA)
nicht aus dem Laufwerkgehäuse nehmen! Falls die
HDA beschädigt ist, schicken Sie das gesamte
Laufwerk zur Reparatur ein.
• Die HDA ist nicht vor Ort reparierbar und darf nicht
auseinandergenommen werden! Öffnen der
versiegeltenHDAdurchanderePersonenalsdiefürdie
werkseitige Reparatur zuständigen hat eine
Beschädigung der Komponenten und Erlöschen des
Garantieanspruchs zur Folge.
Als Teilkomponente ist dieses Laufwerk für die Installa-
tion und den Betrieb in Übereinstimmung mit UL 1950,
IEC950, EN60950, CSA C22.2 950 und VDE0805
vorgesehen.
Seagateistständigbemüht,dieZulassungsfähigkeitvon
Seagate-Produkten im Rahmen der gegenwärtig
8 Barracuda 2LP Installation Guide, Rev. E

geltendenStandardszugewährleisten.Zudentypischen
Anwendungen dieser Festplattenwerke zählen
Systemeinbau durch den Kunden und die Konstruktion
vonUntersystemen.Sicherheitsbehördengewähreneine
bedingte Zulassung für Komponenten wie das Barra-
cuda-Festplattenlaufwerk vorbehaltlich der endgültigen
ZulasssungimEndprodukt.DesignervonUntersystemen
sind dafür verantwortlich, die Voraussetzungen für die
Einhaltung sicherheits- oder aufsichtsbehördlicher
Vorschriftenin ihrenEndprodukten und- fallsgesetzlich
vorgeschrieben - für die Zulassung zu schaffen.
Eine Grundvoraussetzung zur Einhaltung der
Sicherheitsanforderungen ist die Bereitstellung
eines Überlastschutzes für die SELV-
Versorgungsspannungen des Laufwerks.
DiesesGerätisteineBaugruppeundunterliegtalssolche
nicht den Anforderungen der FCC oder ähnlicher
nationaler Behörden für eigenständige Geräte.
Technische Testergebnisse zu elektromagnetische
Strahlung sind für Designer von Untersystemen auf
AnfragevonderSeagate-Sicherheitsabteilungerhältlich.
Barracuda 2LP Installation Guide, Rev. E 9

Technical support services
Seagate Technology provides technical support litera-
ture and diagnostic utilities to authorized distributors.
Please contact your dealer for technical support and
installationtroubleshooting.Producttechnicalsupportis
availableforallSeagateproductsbycallingtheSeaFAX™,
SeaFONE™, SeaTDD™, or SeaBOARD™ services.
Thesearetollcallsifyoudialfromoutsideofthenumber’s
local dialing area.
SeaFAX:
USA [phone]; England 44-62-847-7080
Use a touch-tone telephone to access Seagate’s auto-
matedFAXsystemandselecttechnicalsupportinforma-
tion by return FAX. This service is available 24 hours a
day, 7 days a week.
CompuServe Forum
Online support for Seagate products is available on
CompuServe. This includes an extensive question and
answermessagebase,downloadableutilities,anddocu-
mentation files in Adobe™ Acrobat™ format which you
can download and view from your own computer. Type
“Go Seagate” from within CompuServe to access this
service.
10 Barracuda 2LP Installation Guide, Rev. E

SeaFONE: [phone]
Technicalsupportspecialistsareavailablefrom8:00A.M.
to 5:00 P.M. PST, Monday through Friday. Recorded
technical information on selected Seagate products is
provided while you are on hold. Recordings are acces-
sible 24 hours a day, 7 days a week.
SeaTDD: [phone]
TDD is a telecommunication device for the deaf where
two people can communicate using a keyboard con-
nected to the phone line. A TDD device is required to
access this service, which is available from 8:00 A.M. to
5:00 P.M. PST, Monday through Friday.
SeaBOARD:
The Seagate Technical Support Bulletin Board System
(BBS) is available 24 hours a day, 7 days a week. A
modemisrequiredtoaccessthisservice.Thecommuni-
cationssoftwaremustbesetforeightdatabits,noparity,
and one stop bit (8N1). These operate at 300 to 9600
baud. With this service you can access:
• Specifications and jumper configurations
• Reprints of Seagate documentation
• Utilities that you can download to your own computer
Barracuda 2LP Installation Guide, Rev. E 11

Location Modem 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
12 Barracuda 2LP Installation Guide, Rev. E

Barracuda 2LP Installation Guide, Rev. E 13
Figure 1. Barracuda 2LP disc drive (N/ND model shown)
SCSI I/O
Connector
DC Power Connector
General description
Barracuda 2LP SCSI disc drives are high-speed, ran-
dom-access digital-data storage devices.
The drive is a component for installation in an enclosure
designed for the drive. This is often a rack within the
system or an external enclosure designed to house one
or more disc drives or other peripheral units. In either
case,thediscdrivemustreceiveadequatecooling(refer
to “Providing adequate cooling”) and it must be suffi-
cientlygroundedand shieldedfromemissions.The Bar-
racuda 2LP Product Manual (part number 83328930)
contains guidelines for a properly designed enclosure.

14 Barracuda 2LP Installation Guide, Rev. E
Characteristics ST31250 ST32550
Interface Fast SCSI-21Fast SCSI-21
Capacity
Unformatted 1,205.3 Mbytes 2,541.3 Mbytes
Formatted21,020.9 Mbytes 2,147.4 Mbytes
Recording
Cylinders (user) 3,711 3,510
Read/write data heads 5 11
Servo heads 1 1
Avg bytes/track 64,160 64,160
Seek time3
Average read 8.0 msec 8.0 msec
Average write 9.0 msec 9.0 msec
Disc rotation
RPM 7,200 7,200
Average latency 4.17 msec 4.17 msec
Internal transfer rate 47.5 to 72.0 49.4 to 72.0
(Mbits/sec)
Max sync. SCSI transfer rate
N/ND 10 Mbytes/sec 10 Mbytes/sec
W/WD/WC/DC 20 Mbytes/sec 20 Mbytes/sec
Multi-segmented cache 512 Kbytes 512 Kbytes

Barracuda 2LP Installation Guide, Rev. E 15
1Can also be operated according to SCSI-1 protocol.
2Standard factory units are formatted as follows:
512 data bytes per sector
9 spare sectors per cylinder
1 cylinder at the innter track reserved for spares
3Not including on-board controller overhead.

16 Barracuda 2LP Installation Guide, Rev. E
DC power requirements Single-ended Differential
++
++
+5V11 ++
++
+12V ++
++
+5V11 ++
++
+12V
Voltage regulation5±±
±±
±5% ±±
±±
±5%2±±
±±
±5% ±±
±±
±5%2
Amps
Maximum operating current10.93 0.6 1.17 0.6
Maximum starting current
Peak DC3,60.93 1.35 1.00 1.35
Peak AC3−1.93 −1.93
Delayed motor start (max)1,4 0.88 0.12 0.92 0.12
Peak operating current
Typ DC1,10 0.91 0.57 1.13 0.57
Max DC10.93 0.60 1.17 0.60
Max (peak) 1.00 1.56 1.95 1.56
Track following (DC)
at OD10.91 0.5 0.99 0.50
at ID10.88 0.51 0.96 0.51
Read track
OD DC1,14 0.96 0.53 1.35 0.53
AC 1.03 0.73 1.95 0.73
Seeking
Typical DC1,13 0.89 0.78 0.99 0.78
Maximum DC10.92 0.82 1.10 0.82
Maximum (peak) AC 0.95 1.60 1.67 1.60

Barracuda 2LP Installation Guide, Rev. E 17
1Measured with an average reading DC ammeter. Instanta-
neous +12V current peaks will exceed these values.
2A −10% tolerance is permissible during initial start of the
spindle but must return to±5% before reaching 7,200 RPM.
The±5% must be maintained after the drive signifies that its
power-up sequence has been completed and that the drive
is able to accept selection by the host initiator.
3See the +12V current profile in the
Barracuda 2LP Product
Manual (publication number 83328930).
4ThisconditionoccurswhentheMotorStartoptionisenabled
and the drive has not yet received a Start Motor command.
5See “Conducted noise immunity” in the
Barracuda 2LP
ProductManual. Thespecifiedvoltagetoleranceisinclusive
of ripple, noise, and transient response.
6At power-up, the motor current regulator limits the +12V
current to an average value of less than 1.4A, although
instantaneous peaks may exceed this value. These peaks
should measure 5 msec duration or less.
7Minimum current loading for each supply voltage is not less
than 4% of the maximum operating current shown.
8Use separate ground returns for +5 and +12V supplies.
9Where power is provided to multiple drives from a common
supply, carefully consider individual-drive power require-
ments.Wheremultipleunitsarepoweredonsimultaneously,
besurethepeakstartingcurrentisavailabletoeachdevice.
10Operating condition is a third-stroke seek at OD and read
one Track. The command is issued every 0.075 seconds
(every 0.063 seconds on wide and SCA drives).

18 Barracuda 2LP Installation Guide, Rev. E
11No terminator power. See Section 11.7.3.4 in the
Barra-
cuda 2LP Product Manual.
12All power-saving features are enabled (ASA II code only).
13Seeking is defined as a third-stroke seek at OD. The com-
mand is issued every 20 msec.
14Read track is defined as repeat reads of track 15 with a
78% duty cycle on N models, 32% duty cycle on W
models, 48% duty cycle on WC models, 60% duty cycle
on ND models, 44% duty cycle on WD models, and 44%
duty cycle on DC models.