IBM ThinkPad T21 Owner's manual

IBM Mobile Systems
ThinkPad Computer
Hardware Maintenance Manual
April 2002
This manual supports:
ThinkPad T20, T21, T22, T23
(MT 2647/2648)
ThinkPad Dock (MT 2631)


Note
Before using this information and the product it
supports, be sure to read the general information
under “Notices” on page 174.
First Edition (April 2002)
The following paragraph does not apply to the United
Kingdom or any country where such provisions are
inconsistent with local law:
INTERNATIONAL BUSINESS MACHINES CORPORATION
PROVIDES THIS PUBLICATION “AS IS” WITHOUT ANY
WARRANTY OF ANY KIND, EITHER EXPRESS OR
IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
LIMITED WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE. Some states
do not allow disclaimer or express or implied warranties in
certain transactions; therefore, this statement may not
apply to you.
This publication could include technical inaccuracies or
typographical errors. Changes are periodically made to the
information herein; these changes will be incorporated in
new editions of the publication. IBM may make
improvements or changes to the products or the programs
described in this publication at any time.
It is possible that this publication may contain references
to, or information about, IBM products (machines and
programs), programming, or services that are not
announced in your country. Such references or information
must not be construed to mean that IBM intends to
announce such IBM products, programming, or services in
your country.
Requests for technical information about IBM products
should be made to your IBM authorized dealer or your IBM
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© Copyright International Business Machines
Corporation 2002. All rights reserved.
US Government Users Restricted Rights – Use, duplication
or disclosure restricted by GSA ADP Schedule Contract
with IBM Corp.

About this manual
This manual contains service and reference information for
IBM ThinkPad T20, T21, T22, T23 (MT2647, 2648), and
ThinkPad Dock (MT2631) products. Use this manual along
with the advanced diagnostic tests to troubleshoot
problems.
The manual is divided into sections as follows:
vThe common sections provide general information,
guidelines, and safety information required in servicing
computers.
vThe product-specific section includes service, reference,
and product-specific parts information.
Important
This manual is intended for trained service
personnel who are familiar with ThinkPad products.
Use this manual along with the advanced diagnostic
tests to troubleshoot problems effectively.
Before servicing an IBM ThinkPad product, be sure
to review the safety information under “Safety
notices: multilingual translations”on page 3, “Safety
information”on page 13, and “Laser compliance
statement”on page 18.
© Copyright IBM Corp. 2002 iii

iv ThinkPad T20, T21, T22, T23 (MT 2647/2648)

Contents
About this manual ...........iii
Introduction .............1
Important service information .........1
Strategy for replacing FRUs ........1
How to use error messages ........2
Diskette compatibility matrix .........2
Safety notices: multilingual translations ......3
Safety information............13
General safety............13
Electrical safety ...........14
Safety inspection guide .........15
Handling devices that are sensitive to electorostatic
discharge ............16
Grounding requirements .........17
Laser compliance statement.........18
General descriptions ..........21
Read this first .............21
What to do first ...........21
Related service information .........23
Service web site ...........23
Restoring the preloaded system ......23
Passwords .............26
Power management ..........28
Checkout guide ............32
Testing the computer ..........33
Detecting system information with PC-Doctor. . . 34
Power system checkout .........35
ThinkPad T20, T21, T22 and T23 series.....39
Product overview ............41
Specifications ............43
Status indicators ...........45
FRU Tests .............47
Fn key combinations ..........48
Symptom-to-FRU index ..........49
Numeric error codes ..........49
Error messages ...........52
Beep symptoms ...........53
No-beep symptoms ..........53
LCD-related symptoms .........54
Intermittent problems ..........55
Undetermined problems .........55
FRU replacement notices .........56
Screw notices ............56
Retaining serial numbers.........57
Removing and replacing a FRU........59
1010 Battery pack...........60
1020 Backup battery ..........61
© Copyright IBM Corp. 2002 v

1030 Hard-disk drive ..........63
1040 DIMM ............65
1050 Mini PCI adapter .........66
1060 Ethernet daughter card .......71
1070 Ultrabay 2000 device ........73
1080 Keyboard ...........74
1090 Keyboard CRU insulator .......82
1100 Hinge cover ...........83
1110 Keyboard bezel ..........88
1120 Fan assembly ..........94
1130CPU.............98
1140 PC Card slot assembly .......100
1150 Speaker ...........103
1160 Hard-disk bay ..........105
1170 Ultrabay 2000 slot ........107
1180 System board ..........113
1190 Secure chip ..........117
1200 Microphone cable.........118
2010 LCD assembly..........121
2020 Front bezel...........122
2030 Inverter card ..........123
2040 LCD panel ...........125
2050 Antenna assembly ........128
2060 Sub card ...........131
3010 ThinkPad Dock PCI cover ......133
3020 ThinkPad Dock top cover ......136
Locations ..............140
Front view ............140
Rear view.............141
Bottom view ............142
Parts list . . ............143
T20, T21, T22 and T23 series model matrix 146
Overall .............147
AC adapters ............156
LCD FRUs ............157
Keyboard .............160
Recovery CDs ...........161
Miscellaneous parts ..........170
Optional FRUs ...........171
Common parts list ..........172
Notices . . ............174
Trademarks ............174
vi ThinkPad T20, T21, T22, T23 (MT 2647/2648)

Introduction
Important service information
Important
BIOS and device driver fixes are
customer-installable. The BIOS and device drivers
are posted on the IBM support site
http://www.ibm.com/pc/support
Advise customers to contact the PC Company
HelpCenter at 800-772-2227 if they need assistance
in obtaining or installing any diskette fixes.
Customers in Canada should call IBM HelpPC at
800-565-3344 for assistance or download
information.
Strategy for replacing FRUs
Before replacing parts
Make sure that all diskette fixes are installed before
replacing any FRUs listed in this manual.
Use the following strategy to prevent unnecessary expense
for replacing and servicing FRUs:
vIf you are instructed to replace a FRU but the
replacement does not correct the problem, reinstall
the original FRU before you continue.
vSome computers have both a processor board and a
system board. If you are instructed to replace either the
processor board or the system board, and replacing one
of them does not correct the problem, reinstall that
board, and then replace the other one.
vIf an adapter or device consists of more than one FRU,
any of the FRUs may be the cause of the error. Before
replacing the adapter or device, remove the FRUs, one
by one, to see if the symptoms change. Replace only
the FRU that changed the symptoms.
Attention: The setup configuration on the computer you
are servicing may have been customized. Running
Automatic Configuration may alter the settings. Note the
current configuration settings (using the View Configuration
option); then, when service has been completed, verify that
those settings remain in effect.
© Copyright IBM Corp. 2002 1

Strategy for replacing a hard-disk drive
Always try to run a low-level format before replacing a
hard-disk drive.
Attention: The drive startup sequence in the computer
you are servicing may have been changed. Be extremely
careful during write operations such as copying, saving, or
formatting. If you select an incorrect drive, data or
programs can be overwritten.
How to use error messages
Use the error codes displayed on the screen to diagnose
failures. If more than one error code is displayed, begin the
diagnosis with the first error code. Whatever causes the
first error code may also cause false error codes. If no
error code is displayed, see if the error symptom is listed
in the Symptom-to-FRU Index for the computer you are
servicing.
Diskette compatibility matrix
The compatibility of each of the drives with the diskettes
for it is as follows:
Diskette
drive Diskette capacity Compatibility
3.5-inch 1.0 MB Read and write
2.0 MB Read and write
4.0 MB Not compatible
Important service information
2ThinkPad T20, T21, T22, T23 (MT 2647/2648)

Safety notices: multilingual translations
In this manual, safety notices appear in English with a
page number reference to the appropriate multilingual,
translated safety notice found in this section.
The following safety notices are provided in English,
French, German, Italian, and Spanish.
Safety notice 1
Before the computer is powered-on after FRU
replacement, make sure all screws, springs, and other
small parts are in place and are not left loose inside
the computer. Verify this by shaking the computer and
listening for rattling sounds. Metallic parts or metal
flakes can cause electrical shorts.
Avant de remettre l’ordinateur sous tension après
remplacement d’une unitéen clientèle, vérifiez que
tous les ressorts, vis et autres pièces sont bien en
place et bien fixées. Pour ce faire, secouez l’unitéet
assurez-vous qu’aucun bruit suspect ne se produit. Des
pièces métalliques ou des copeaux de métal pourraient
causer un court-circuit.
Bevor nach einem FRU-Austausch der Computer
wieder angeschlossen wird, mußsichergestellt werden,
daßkeine Schrauben, Federn oder andere Kleinteile
fehlen oder im Gehäuse vergessen wurden. Der
Computer mußgeschüttelt und auf Klappergeräusche
geprüft werden. Metallteile oder-splitter können
Kurzschlüsse erzeugen.
Prima di accendere l’elaboratore dopo che éstata
effettuata la sostituzione di una FRU, accertarsi che
tutte le viti, le molle e tutte le altri parti di piccole
dimensioni siano nella corretta posizione e non siano
sparse all’interno dell’elaboratore. Verificare ciò
scuotendo l’elaboratore e prestando attenzione ad
eventuali rumori; eventuali parti o pezzetti metallici
possono provocare cortocircuiti pericolosi.
Antes de encender el sistema despues de sustituir una
FRU, compruebe que todos los tornillos, muelles y
demás piezas pequeñas se encuentran en su sitio y no
se encuentran sueltas dentro del sistema.
Compruébelo agitando el sistema y escuchando los
posibles ruidos que provocarían. Las piezas metálicas
pueden causar cortocircuitos eléctricos.
Safety notices
Introduction 3

Safety notice 2
DANGER
Some standby batteries contain a small amount of
nickel and cadmium. Do not disassemble a standby
battery, recharge it, throw it into fire or water, or
short-circuit it. Dispose of the battery as required
by local ordinances or regulations. Use only the
battery in the appropriate parts listing. Use of an
incorrect battery can result in ignition or explosion
of the battery.
Certaines batteries de secours contiennent du
nickel et du cadmium. Ne les démontez pas, ne les
rechargez pas, ne les exposez ni au feu ni à l’eau.
Ne les mettez pas en court-circuit. Pour les mettre
au rebut, conformez-vous à la réglementation en
vigueur. Lorsque vous remplacez la pile de
sauvegarde ou celle de l’horloge temps réel, veillez
à n’utiliser que les modèles cités dans la liste de
pièces détachées adéquate. Une batterie ou une
pile inappropriée risque de prendre feu ou
d’exploser.
Die Bereitschaftsbatterie, die sich unter dem
Diskettenlaufwerk befindet, kann geringe Mengen
Nickel und Cadmium enthalten. Sie darf nur durch
die Verkaufsstelle oder den IBM Kundendienst
ausgetauscht werden. Sie darf nicht zerlegt,
wiederaufgeladen, kurzgeschlossen, oder Feuer
oder Wasser ausgesetzt werden. Die Batterie kann
schwere Verbrennungen oder Verätzungen
verursachen. Bei der Entsorgung die örtlichen
Bestimmungen für Sondermüll beachten. Beim
Ersetzen der Bereitschafts-oder Systembatterie nur
Batterien des Typs verwenden, der in der
Ersatzteilliste aufgeführt ist. Der Einsatz falscher
Batterien kann zu Entzündung oder Explosion
führen.
(continued)
Safety notices
4ThinkPad T20, T21, T22, T23 (MT 2647/2648)

(continuation of safety notice 2)
Alcune batterie di riserva contengono una piccola
quantitàdi nichel e cadmio. Non smontarle,
ricaricarle, gettarle nel fuoco o nell’acqua né
cortocircuitarle. Smaltirle secondo la normativa in
vigore (DPR 915/82, successive disposizioni e
disposizioni locali). Quando si sostituisce la
batteria dell’RTC (real time clock) o la batteria di
supporto, utilizzare soltanto i tipi inseriti
nell’appropriato Catalogo parti. L’impiego di una
batteria non adatta potrebbe determinare l’incendio
ol’esplosione della batteria stessa.
Algunas baterías de reserva contienen una
pequeña cantidad de níquel y cadmio. No las
desmonte, ni recargue, ni las eche al fuego o al
agua ni las cortocircuite. Deséchelas tal como
dispone la normativa local. Utilice sólo baterías que
se encuentren en la lista de piezas. La utilización
de una batería no apropiada puede provocar la
ignición o explosión de la misma.
Safety notices
Introduction 5

Safety notice 3
DANGER
The battery pack contains small amounts of nickel.
Do not disassemble it, throw it into fire or water, or
short-circuit it. Dispose of the battery pack as
required by local ordinances or regulations. Use
only the battery in the appropriate parts listing
when replacing the battery pack. Use of an
incorrect battery can result in ignition or explosion
of the battery.
La batterie contient du nickel. Ne la démontez pas,
ne l’exposez ni au feu ni àl’eau. Ne la mettez pas
en court-circuit. Pour la mettre au rebut,
conformez-vous àla réglementation en vigueur.
Lorsque vous remplacez la batterie, veillez à
n’utiliser que les modèles cités dans la liste de
pièces détachées adéquate. En effet, une batterie
inappropriée risque de prendre feu ou d’exploser.
Akkus enthalten geringe Mengen von Nickel. Sie
dürfen nicht zerlegt, wiederaufgeladen,
kurzgeschlossen, oder Feuer oder Wasser
ausgesetzt werden. Bei der Entsorgung die
örtlichen Bestimmungen für Sondermüll beachten.
Beim Ersetzen der Batterie nur Batterien des Typs
verwenden, der in der Ersatzteilliste aufgeführt ist.
Der Einsatz falscher Batterien kann zu Entzündung
oder Explosion führen.
La batteria contiene piccole quantitàdi nichel. Non
smontarla, gettarla nel fuoco o nell’acqua né
cortocircuitarla. Smaltirla secondo la normativa in
vigore (DPR 915/82, successive disposizioni e
disposizioni locali). Quando si sostituisce la
batteria, utilizzare soltanto i tipi inseriti
nell’appropriato Catalogo parti. L’impiego di una
batteria non adatta potrebbe determinare l’incendio
ol’esplosione della batteria stessa.
(continued)
Safety notices
6ThinkPad T20, T21, T22, T23 (MT 2647/2648)

Safety notice 4
DANGER
(continuation of safety notice 3)
Las baterías contienen pequeñas cantidades de
níquel. No las desmonte, ni recargue, ni las eche al
fuego o al agua ni las cortocircuite. Deséchelas tal
como dispone la normativa local. Utilice sólo
baterías que se encuentren en la lista de piezas al
sustituir la batería. La utilización de una bateríano
apropiada puede provocar la ignición o explosión
de la misma.
The lithium battery can cause a fire, an explosion,
or a severe burn. Do not recharge it, remove its
polarized connector, disassemble it, heat it above
100°C (212°F), incinerate it, or expose its cell
contents to water. Dispose of the battery as
required by local ordinances or regulations. Use
only the battery in the appropriate parts listing. Use
of an incorrect battery can result in ignition or
explosion of the battery.
La pile de sauvegarde contient du lithium. Elle
présente des risques d’incendie, d’explosion ou de
brûlures graves. Ne la rechargez pas, ne retirez pas
son connecteur polariséet ne la démontez pas. Ne
l’exposez pas àune temperature supérieure à
100°C, ne la faites pas brûler et n’en exposez pas
le contenu àl’eau. Mettez la pile au rebut
conformément àla réglementation en vigueur. Une
pile inappropriée risque de prendre feu ou
d’exploser.
(continued)
Safety notices
Introduction 7

(continuation of safety notice 4)
Die Systembatterie ist eine Lithiumbatterie. Sie
kann sich entzünden, explodieren oder schwere
Verbrennungen hervorrufen. Batterien dieses Typs
dürfen nicht aufgeladen, zerlegt, über 100 C erhitzt
oder verbrannt werden. Auch darf ihr Inhalt nicht
mit Wasser in Verbindung gebracht oder der zur
richtigen Polung angebrachte Verbindungsstecker
entfernt werden. Bei der Entsorgung die örtlichen
Bestimmungen für Sondermüll beachten. Beim
Ersetzen der Batterie nur Batterien des Typs
verwenden, der in der Ersatzteilliste aufgeführt ist.
Der Einsatz falscher Batterien kann zu Entzündung
oder Explosion führen.
La batteria di supporto e una batteria al litio e puo
incendiarsi, esplodere o procurare gravi ustioni.
Evitare di ricaricarla, smontarne il connettore
polarizzato, smontarla, riscaldarla ad una
temperatura superiore ai 100 gradi centigradi,
incendiarla o gettarla in acqua. Smaltirla secondo
la normativa in vigore (DPR 915/82, successive
disposizioni e disposizioni locali). L’impiego di una
batteria non adatta potrebbe determinare l’incendio
ol’esplosione della batteria stessa.
La batería de repuesto es una batería de litio y
puede provocar incendios, explosiones o
quemaduras graves. No la recargue, ni quite el
conector polarizado, ni la desmonte, ni caliente por
encima de los 100°C (212°F), ni la incinere ni
exponga el contenido de sus celdas al agua.
Deséchela tal como dispone la normativa local.
Safety notices
8ThinkPad T20, T21, T22, T23 (MT 2647/2648)

Safety notice 5
If the LCD breaks and the fluid from inside the LCD
gets into your eyes or on your hands, immediately
wash the affected areas with water for at least 15
minutes. Seek medical care if any symptoms from the
fluid are present after washing.
Si le panneau d’affichage àcristaux liquides se brise et
que vous recevez dans les yeux ou sur les mains une
partie du fluide, rincez-les abondamment pendant au
moins quinze minutes. Consultez un médecin si des
symptômes persistent après le lavage.
Die Leuchtstoffröhre im LCD-Bildschirm enthält
Quecksilber. Bei der Entsorgung die örtlichen
Bestimmungen für Sondermüll beachten. Der
LCD-Bildschirm besteht aus Glas und kann zerbrechen,
wenn er unsachgemäß behandelt wird oder der
Computer auf den Boden fällt. Wenn der Bildschirm
beschädigt ist und die darin befindliche Flüssigkeit in
Kontakt mit Haut und Augen gerät, sollten die
betroffenen Stellen mindestens 15 Minuten mit Wasser
abgespült und bei Beschwerden anschließend ein Arzt
aufgesucht werden.
Nel caso che caso l’LCD si dovesse rompere ed il
liquido in esso contenuto entrasse in contatto con gli
occhi o le mani, lavare immediatamente le parti
interessate con acqua corrente per almeno 15 minuti;
poi consultare un medico se i sintomi dovessero
permanere.
Si la LCD se rompe y el fluido de su interior entra en
contacto con sus ojos o sus manos, lave
inmediatamente las áreas afectadas con agua durante
15 minutos como mínimo. Obtenga atención medica si
se presenta algúnsíntoma del fluido despues de
lavarse.
Safety notices
Introduction 9

Safety notice 6
DANGER
To avoid shock, do not remove the plastic cover
that protects the lower part of the inverter card.
Afin d’éviter tout risque de choc électrique, ne
retirez pas le cache en plastique protégeant la
partie inférieure de la carte d’alimentation.
Aus Sicherheitsgründen die Kunststoffabdeckung,
die den unteren Teil der Spannungswandlerplatine
umgibt, nicht entfernen.
Per evitare scosse elettriche, non rimuovere la
copertura in plastica che avvolge la parte inferiore
della scheda invertitore.
Para evitar descargas, no quite la cubierta de
plástico que rodea la parte baja de la tarjeta
invertida.
Safety notices
10 ThinkPad T20, T21, T22, T23 (MT 2647/2648)

Safety notice 7
DANGER
Though the main batteries have low voltage, a
shorted or grounded battery can produce enough
current to burn personnel or combustible materials.
Bien que le voltage des batteries principales soit
peu élevé, le court-circuit ou la mise àla masse
d’une batterie peut produire suffisamment de
courant pour brûler des matériaux combustibles ou
causer des brûlures corporelles graves.
Obwohl Hauptbatterien eine niedrige Spannung
haben, können sie doch bei Kurzschlußoder
Erdung genug Strom abgeben, um brennbare
Materialien zu entzünden oder Verletzungen bei
Personen hervorzurufen.
Sebbene le batterie di alimentazione siano a basso
voltaggio, una batteria in corto circuito o a massa
puòfornire corrente sufficiente da bruciare
materiali combustibili o provocare ustioni ai tecnici
di manutenzione.
Aunque las baterías principales tienen un voltaje
bajo, una batería cortocircuitada o con contacto a
tierra puede producir la corriente suficiente como
para quemar material combustible o provocar
quemaduras en el personal.
Safety notices
Introduction 11

Safety notice 8
DANGER
Before removing any FRU, power off the computer,
unplug all power cords from electrical outlets,
remove the battery pack, and then disconnect any
interconnecting cables.
Avant de retirer une unitéremplaçable en clientèle,
mettez le système hors tension, débranchez tous
les cordons d’alimentation des socles de prise de
courant, retirez la batterie et déconnectez tous les
cordons d’interface.
Die Stromzufuhr mußabgeschaltet, alle Stromkabel
aus der Steckdose gezogen, der Akku entfernt und
alle Verbindungskabel abgenommen sein, bevor
eine FRU entfernt wird.
Prima di rimuovere qualsiasi FRU, spegnere il
sistema, scollegare dalle prese elettriche tutti i cavi
di alimentazione, rimuovere la batteria e poi
scollegare i cavi di interconnessione.
Antes de quitar una FRU, apague el sistema,
desenchufe todos los cables de las tomas de
corriente eléctrica, quite la bateríay,a
continuación, desconecte cualquier cable de
conexión entre dispositivos.
Safety notices
12 ThinkPad T20, T21, T22, T23 (MT 2647/2648)

Safety information
The following section presents the safety information that
you need to be familiar with before servicing an IBM
mobile computer.
General safety
Follow these rules to ensure general safety:
vObserve good housekeeping in the area of the
machines during and after maintenance.
vWhen lifting any heavy object:
1. Ensure you can stand safely without slipping.
2. Distribute the weight of the object equally between
your feet.
3. Use a slow lifting force. Never move suddenly or
twist when you attempt to lift.
4. Lift by standing or by pushing up with your leg
muscles; this action removes the strain from the
muscles in your back. Do not attempt to lift any
object that weighs more than 16 kg (35 lb) or objects
that you think are too heavy for you.
vDo not perform any action that causes hazards to the
customer, or that makes the equipment unsafe.
vBefore you start the machine, ensure that other service
representatives and the customer’s personnel are not in
a hazardous position.
vPlace removed covers and other parts in a safe place,
away from all personnel, while you are servicing the
machine.
vKeep your toolcase away from walk areas so that other
people will not trip over it.
vDo not wear loose clothing that can be trapped in the
moving parts of a machine. Make sure that your sleeves
are fastened or rolled up above your elbows. If your hair
is long, fasten it.
vInsert the ends of your necktie or scarf inside clothing or
fasten it with a nonconductive clip, approximately 8
centimeters (3 inches) from the end.
vDo not wear jewelry, chains, metal-frame eyeglasses, or
metal fasteners for your clothing.
Attention: Metal objects are good electrical
conductors.
vWear safety glasses when you are hammering, drilling,
soldering, cutting wire, attaching springs, using solvents,
or working in any other conditions that might be
hazardous to your eyes.
Safety information
Introduction 13

vAfter service, reinstall all safety shields, guards, labels,
and ground wires. Replace any safety device that is
worn or defective.
vReinstall all covers correctly before returning the
machine to the customer.
Electrical safety
Observe the following rules when working on electrical
equipment.
Important
Use only approved tools and test equipment. Some
hand tools have handles covered with a soft
material that does not insulate you when working
with live electrical currents.
Many customers have, near their equipment, rubber
floor mats that contain small conductive fibers to
decrease electrostatic discharges. Do not use this
type of mat to protect yourself from electrical shock.
vFind the room emergency power-off (EPO) switch,
disconnecting switch, or electrical outlet. If an electrical
accident occurs, you can then operate the switch or
unplug the power cord quickly.
vDo not work alone under hazardous conditions or near
equipment that has hazardous voltages.
vDisconnect all power before:
–Performing a mechanical inspection
–Working near power supplies
–Removing or installing main units
vBefore you start to work on the machine, unplug the
power cord. If you cannot unplug it, ask the customer to
power-off the wall box that supplies power to the
machine and to lock the wall box in the off position.
vIf you need to work on a machine that has exposed
electrical circuits, observe the following precautions:
–Ensure that another person, familiar with the
power-off controls, is near you.
Attention: Another person must be there to switch
off the power, if necessary.
–Use only one hand when working with powered-on
electrical equipment; keep the other hand in your
pocket or behind your back.
Attention: An electrical shock can occur only when
there is a complete circuit. By observing the above
rule, you may prevent a current from passing through
your body.
Safety information
14 ThinkPad T20, T21, T22, T23 (MT 2647/2648)