IBM ThinkPad T20, ThinkPad T22, MT 2648, ThinkPad Dock, ThinkPad T23 Hardware Maintenance Manual



IBM Mobile Systems
ThinkPad Computer
Hardware Maintenance Manual

August 2001

This manual supports:

ThinkPad T20, T21, T22, T23

ThinkPad Dock (MT 2631)

(MT 2647/2648)

Note

Before using this information and the product it
supports, be sure to read the general information
under “Notices” on page 170.

Second Edition (August 2001)
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
marketing representative.

© Copyright International Business Machines
Corporation 2001. All rights reserved.

US Government Users Restricted Rights – Use, duplication
or disclosure restricted by GSA ADP Schedule Contract
with IBM Corp.

Contents

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 electrostatic discharge-sensitive devices 16

Grounding requirements .........17

Laser compliance statement.........17

General descriptions ..........21

Read this first .............21

What to do first ...........21

Related service information .........23

Service web site ...........23

Product recovery program ........23

Passwords .............25

Power management ..........27

Checkout guide ............31

Testing the computer ..........31

Detecting system information with PC-Doctor. . . 33

Power system checkout .........34

ThinkPad T20, T21, T22 and T23 series.....37

Product overview ............39

Specifications ............39

Status indicators ...........42

FRU Tests .............44

Fn key combinations ..........46

Symptom-to-FRU index ..........47

Numeric error codes ..........47

Error messages ...........50

Beep symptoms ...........51

No beep symptoms ..........51

LCD-related symptoms .........52

Intermittent problems ..........53

Undetermined problems .........53

FRU replacement notices .........54

Screw notices ............54

Retaining serial numbers.........55

Removing and replacing a FRU........57

1010 Battery pack...........58

1020 Backup battery ..........59

1030 Hard-disk drive ..........61

1040 DIMM ............63

1050 Mini PCI adapter .........64

© Copyright IBM Corp. 2001

iii

1060 Ethernet daughter card .......68

1070 Ultrabay 2000 device ........71

1080 Keyboard ...........72

1090 Keyboard CRU insulator .......80

1100 Hinge cover ...........81

1110 Keyboard bezel ..........86

1120 Fan assembly ..........92

1130CPU.............97

1140 PC Card slot assembly .......99

1150 Speaker ...........102

1160 Hard-disk bay ..........104

1170 Ultrabay 2000 slot ........106

1180 System board ..........113

1190 Secure chip ..........117

1200 Microphone cable.........118

2010 LCD assembly..........119

2020 Front bezel...........122

2030 Inverter card ..........123

2040 LCD panel ...........124

2050 Antenna assembly ........128

2060 Sub card ...........131

3010 ThinkPad Dock PCI cover ......133

3020 ThinkPad Dock top cover ......135

Locations ..............140

Front view ............140

Rear view.............141

Bottom view ............142

Parts list ..............143

T20, T21, T22 and T23 series model matrix 143

Overall .............146

LCD FRUs ............154

Keyboard .............156

Recovery CDs for T22 series .......157

Recovery CDs for T23 series .......159

Miscellaneous parts ..........161

Optional FRUs ...........167

Common parts list ..........168

Notices ..............170

Trademarks ............170

iv 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 FRU
replacement and service expense:

v If you are instructed to replace a FRU but the

replacement does not correct the problem, reinstall
the original FRU before you continue.

v Some 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.

v If 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.

© Copyright IBM Corp. 2001

1

Important service information

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.

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

3.5-inch 1.0 MB Read and write

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

Diskette
capacity

2.0 MB Read and write

4.0 MB Not compatible

Compatibility

Safety notices

Safety notices: multilingual translations

The safety notices are provided in English, French,
German, Italian, and Spanish, as follows:

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 unité en clientèle, vérifiez que

tous les ressorts, vis et autres pièces sont bien en

place et bien fixées. Pour ce faire, secouez l’unité et

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, muß sichergestellt

werden, daß keine Schrauben, Federn oder andere

Kleinteile fehlen oder im Gehäuse vergessen

wurden. Der Computer muß geschüttelt und auf

Klappergeräusche geprüft werden. Metallteile

oder-splitter können Kurzschlüsse erzeugen.

Prima di accendere l’elaboratore dopo che é stata

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 ci

ÚÚ 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.

Introduction 3

Safety notices

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)

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

Safety notices

Continuation of Safety notice 2

DANGER:

Alcune batterie di riserva contengono una piccola

quantità di 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 o l’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 utilizaciónde

una batería no apropiada puede provocar la ignición

o explosión de la misma.

Introduction 5

Safety notices

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 à l’eau. Ne la mettez pas
en court- circuit. Pour la mettre au rebut,
conformez-vous à la 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 quantità di 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 o l’esplosione della
batteria stessa.

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 explosiónde
la misma.

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

Safety notices

Safety notice 4

DANGER:

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 polarisé et ne la démontez pas. Ne

l’exposez pas à une temperature supérieure à

100°C, ne la faites pas brûler et n’en exposez pas

le contenu à l’eau. Mettez la pile au rebut

conformément à la réglementation en vigueur. Une

pile inappropriée risque de prendre feu ou

d’exploser.

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.

(continued)

Introduction 7

Safety notices

Continuation of Safety notice 4

DANGER:

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.

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

Safety notices

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 à cristaux 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 aprèsle

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.

Introduction 9

Safety notices

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.

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

Safety notices

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 à la 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 Kurzschluß oder

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

può fornire 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.

Introduction 11

Safety notices

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 unité remplaçable 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 muß abgeschaltet, 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 batería y, a continuación,
desconecte cualquier cable de conexión entre
dispositivos.

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

Safety information

Safety information

The following section contains 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:
v Observe good housekeeping in the area of the

machines during and after maintenance.

v When 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

objects that weigh more than 16 kg (35 lb) or objects
that you think are too heavy for you.

v Do not perform any action that causes hazards to the

customer, or that makes the equipment unsafe.

v Before you start the machine, ensure that other service

representatives and the customer’s personnel are not in
a hazardous position.

v Place removed covers and other parts in a safe place,

away from all personnel, while you are servicing the
machine.

v Keep your toolcase away from walk areas so that other

people will not trip over it.

v Do 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.

v Insert the ends of your necktie or scarf inside clothing or

fasten it with a nonconductive clip, approximately 8
centimeters (3 inches) from the end.

v Do not wear jewelry, chains, metal-frame eyeglasses, or

metal fasteners for your clothing.
Attention: Metal objects are good electrical conductors.

v Wear 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.

v After service, reinstall all safety shields, guards, labels,

and ground wires. Replace any safety device that is
worn or defective.

v Reinstall all covers correctly before returning the

machine to the customer.

Introduction 13

Safety information

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.

v Find 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.

v Do not work alone under hazardous conditions or near

equipment that has hazardous voltages.

v Disconnect all power before:

– Performing a mechanical inspection
– Working near power supplies
– Removing or installing main units

v Before 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.

v If 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.

– When using testers, set the controls correctly and

use the approved probe leads and accessories for
that tester.

– Stand on suitable rubber mats (obtained locally, if

necessary) to insulate you from grounds such as
metal floor strips and machine frames.

Observe the special safety precautions when you work
with very high voltages; these instructions are in the

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

Safety information

safety sections of maintenance information. Use
extreme care when measuring high voltages.

v Regularly inspect and maintain your electrical hand tools

for safe operational condition.

v Do not use worn or broken tools and testers.
v Never assume that power has been disconnected from

a circuit. First, check that it has been powered off.

v Always look carefully for possible hazards in your work

area. Examples of these hazards are moist floors,
nongrounded power extension cables, power surges,
and missing safety grounds.

v Do not touch live electrical circuits with the reflective

surface of a plastic dental mirror. The surface is
conductive; such touching can cause personal injury and
machine damage.

v Do not service the following parts with the power on

when they are removed from their normal operating
places in a machine:

– Power supply units
– Pumps
– Blowers and fans
– Motor generators

and similar units. (This practice ensures correct
grounding of the units.)

v If an electrical accident occurs:

– Use caution; do not become a victim yourself.
– Switch off power.
– Send another person to get medical aid.

Safety inspection guide

The purpose of this inspection guide is to assist you in
identifying potentially unsafe conditions. As each machine
was designed and built, required safety items were
installed to protect users and service personnel from injury.
This guide addresses only those items. You should use
good judgment to identify potential safety hazards due to
attachment of non-IBM features or options not covered by
this inspection guide.

If any unsafe conditions are present, you must determine
how serious the apparent hazard could be and whether
you can continue without first correcting the problem.

Consider these conditions and the safety hazards they
present:
v Electrical hazards, especially primary power (primary

voltage on the frame can cause serious or fatal
electrical shock)

v Explosive hazards, such as a damaged CRT face or a

bulging capacitor

v Mechanical hazards, such as loose or missing hardware

Introduction 15

Safety information

To determine whether there are any potentially unsafe
conditions, use the following checklist at the beginning of
every service task. Begin the checks with the power off,
and the power cord disconnected.

Checklist:

1. Check exterior covers for damage (loose, broken, or
sharp edges).

2. Power-off the computer. Disconnect the power cord.

3. Check the power cord for:
a. A third-wire ground connector in good condition.

Use a meter to measure third-wire ground
continuity for 0.1 ohm or less between the external
ground pin and frame ground.

b. The power cord should be the type specified in the

parts list.

c. Insulation must not be frayed or worn.

4. Remove the cover.

5. Check for any obvious non-IBM alterations. Use good
judgment as to the safety of any non-IBM alterations.

6. Check inside the unit for any obvious unsafe
conditions, such as metal filings, contamination, water
or other liquids, or signs of fire or smoke damage.

7. Check for worn, frayed, or pinched cables.

8. Check that the power-supply cover fasteners (screws
or rivets) have not been removed or tampered with.

Handling electrostatic discharge-sensitive devices

Any computer part containing transistors or integrated
circuits (ICs) should be considered sensitive to electrostatic
discharge (ESD). ESD damage can occur when there is a
difference in charge between objects. Protect against ESD
damage by equalizing the charge so that the machine, the
part, the work mat, and the person handling the part are all
at the same charge.

Notes

1. Use product-specific ESD procedures when they
exceed the requirements noted here.

2. Make sure that the ESD protective devices you
use have been certified (ISO 9000) as fully
effective.

When handling ESD-sensitive parts:
v Keep the parts in protective packages until they are

inserted into the product.

v Avoid contact with other people.
v Wear a grounded wrist strap against your skin to

eliminate static on your body.

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

Safety information

v Prevent the part from touching your clothing. Most

clothing is insulative and retains a charge even when
you are wearing a wrist strap.

v Use the black side of a grounded work mat to provide a

static-free work surface. The mat is especially useful
when handling ESD-sensitive devices.

v Select a grounding system, such as those listed below,

to provide protection that meets the specific service
requirement.

Note

The use of a grounding system is desirable but
not required to protect against ESD damage.

– Attach the ESD ground clip to any frame ground,

ground braid, or green-wire ground.

– Use an ESD common ground or reference point

when working on a double-insulated or
battery-operated system. You can use coax or
connector-outside shells on these systems.

– Use the round ground-prong of the AC plug on

AC-operated computers.

Grounding requirements

Electrical grounding of the computer is required for
operator safety and correct system function. Proper
grounding of the electrical outlet can be verified by a
certified electrician.

Laser compliance statement

Some IBM Personal Computer models are equipped from
the factory with an optical storage device; such as a
CD-ROM drive or DVD-ROM drive. They are also sold
separately as options. The drive is certified in the U.S. to
conform to the requirements of the Department of Health
and Human Services 21 Code of Federal Regulations
(DHHS 21 CFR) Subchapter J for Class 1 laser products.
Elsewhere, the drive is certified to conform to the
requirements of the International Electrotechnical
Commission (IEC) 825 and CENELEC EN 60 825 for
Class 1 laser products.

Introduction 17

Laser compliance statement

When a CD-ROM drive, DVD drive or the other laser
product is installed, note the following:

CAUTION:

Use of controls or adjustments or performance
of procedures other than those specified
herein might result in hazardous radiation
exposure.

O uso de controles, ajustes ou desempenho de
procedimentos diferentes daqueles aqui
especificados pode resultar em perigosa
exposição à radiação.

Pour éviter tout risque d’exposition au rayon
laser, respectez les consignes de réglage et
d’utilisation des commandes, ainsi que les
procédures décrites.

Werden Steuer- und Einstellelemente anders
als hier festgesetzt verwendet, kann
gefährliche Laserstrahlung auftreten.

L’utilizzo di controlli, regolazioni o l’esecuzione
di procedure diverse da quelle specificate
possono provocare l’esposizione a.

El uso de controles o ajustes o la ejecución de
procedimientos distintos de los aquí
especificados puede provocar la exposición a
radiaciones peligrosas.

Opening the CD-ROM drive, DVD-ROM drive or the other
optical storage device could result in exposure to
hazardous laser radiation. There are no serviceable parts
inside those drives. Do not open.

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

Laser compliance statement

Some CD-ROM drives, DVD-ROM drives or the other
optical storage devices contain an embedded Class 3A or
Class 3B laser diode. Note the following:

DANGER:

Emits visible and invisible laser radiation when
open. Do not stare into the beam, do not view
directly with optical instruments, and avoid
direct exposure to the beam.

Radiação por raio laser ao abrir. Não olhe fixo
no feixe de luz, não olhe diretamente por meio
de instrumentos óticos e evite exposição direta
com o feixe de luz.

Rayonnement laser si carter ouvert. Évitez de
fixer le faisceau, de le regarder directement
avec des instruments optiques, ou de vous
exposer au rayon.

Laserstrahlung bei geöffnetem Gerät. Nicht
direkt oder über optische Instrumente in den
Laserstrahl sehen und den Strahlungsbereich
meiden.

Kinyitáskor lézersugár!Nenézzen bele se
szabad szemmel, se optikai eszközökkel.
Kerülje a sugárnyalábbal valóérintkezést !

Aprendo l’unità vengono emesse radiazioni
laser. Non fissare il fascio, non guardarlo
direttamente con strumenti ottici e evitare
l’esposizione diretta al fascio.

Radiaciónláser al abrir. No mire fijamente ni
examine con instrumental óptico el haz de luz.
Evite la exposición directa al haz.

Introduction 19

Laser compliance statement

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

General descriptions

This chapter includes descriptions for any ThinkPad model
that has the PC-Doctor DOS diagnostics program. Some
descriptions might not apply to your particular computer.

Read this first

Before you go to the checkout guide, be sure to read this
section.

Important notes

v Only certified trained personnel should

service the computer.

v Read the entire FRU removal and replacement

page before replacing any FRU.

v Use new nylon-coated screws when you

replace FRUs.

v Be extremely careful during such write

operations as copying, saving, or formatting.

Drives in the computer that you are servicing
sequence might have been altered. If you select
an incorrect drive, data or programs might be
overwritten.

v Replace FRUs only for the correct model.

When you replace a FRU, make sure the model
of the machine and the FRU part number are
correct by referring to the FRU parts list.

v A FRU should not be replaced because of a

single, unreproducible failure. Single failures

can occur for a variety of reasons that have
nothing to do with a hardware defect, such as
cosmic radiation, electrostatic discharge, or
software errors. Consider replacing a FRU only
when a problem recurs. If you suspect that a
FRU is defective, clear the error log and run the
test again. If the error does not recur, do not
replace the FRU.

v Be careful not to replace a nondefective FRU.

What to do first

When you do return a FRU, you must include the following
information in the parts exchange form or parts return form
that you attach to it:
__ 1. Name and phone number of servicer
__ 2. Date of service
__ 3. Date on which the machine failed
__ 4. Date of purchase
__ 5. Failure symptoms, error codes appearing on the

display, and beep symptoms

© Copyright IBM Corp. 2001

21

Read this first

__ 6. Procedure index and page number in which the

failing FRU was detected
__ 7. Failing FRU name and part number
__ 8. Machine type, model number, and serial number
__ 9. Customer’s name and address

Note for warranty:

During the warranty period, the customer may be
responsible for repair costs if the computer damage was
caused by misuse, accident, modification, unsuitable
physical or operating environment, or improper
maintenance by the customer. The following list provides
some common items that are not covered under warranty
and some symptoms that might indicate that the system
was subjected to stress beyond normal use.

Before checking problems with the computer, determine
whether the damage is covered under the warranty by
referring to the following:

The following are not covered under warranty:

v LCD panel cracked from the application of excessive

force or from being dropped

v Scratched (cosmetic) parts
v Distortion, deformation or discoloration of the cosmetic

parts

v Cracked or broken plastic parts, broken latches, broken

pins, or broken connectors caused by excessive force

v Damage caused by liquid spilled into the system
v Damage caused by the improper insertion of a PC Card

or the installation of an incompatible card

v Damage caused by foreign material in the diskette drive
v Diskette drive damage caused by pressure on the

diskette drive cover or by the insertion of a diskette with
multiple labels

v Damaged or bent diskette eject button
v Fuses blown by attachment of a nonsupported device
v Forgotten computer password (making the computer

unusable)

v Sticky keys caused by spilling a liquid onto the keyboard

The following symptoms might indicate damage
caused by nonwarranted activities:

v Missing parts might be a symptom of unauthorized

service or modification.

v If the spindle of a hard-disk drive becomes noisy, it may

have been subjected to excessive force, or dropped.

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

Related service information

Related service information

This section provides information about the following:

v “Service web site”
v “Product recovery program”
v “Passwords” on page 25
v “Power management” on page 27

Service web site

When the latest maintenance diskette and the system
program service diskette become available, a notice will be
posted on http://www.ibm.com/pc/partner/infotips

Product recovery program

Restoring the pre-installed software:

To restore the pre-installed software, you can use either
the Product Recovery program or a Recovery CD.

The Product Recovery program is in the Service Partition,
a section of the hard-disk drive is not displayed by
Windows Explorer. Use the Recovery CD if it was provided
with the computer.

Note: The recovery process might take up to 2 hours.
To use the Product Recovery program to restore the

pre-installed software, do the following:

1. Save all files and shut down the desktop.

2. Turn off the computer.

3. Turn on the computer. A message appears on the
screen: “To start the Product Recovery program,
press F11”. Press F11 quickly; this message is
displayed for only a few seconds.

Note: If this message does not appear, you can use a

Recovery Repair diskette to get access to the
Product Recovery program. (Directions for
making a Recovery Repair diskette are given in
“To create a recovery repair diskette” on

4. From the list displayed on the screen, select the

5. Select the recovery options you want, and follow the

page 24.)

operating system you want to recover.

instructions on the screen.

Creating the service partition:

To create the Service Partition and install the preloaded
system from the Recovery CD, do the following:

To create the Service Partition (SP):

1. Erase all partitions on the hard-disk drive, using FDISK
or a similar application.

General descriptions 23

Related service information

2. Boot with the Recovery CD (and the boot diskette if
required).

3. Following message appears: “Your computer

originally included a Product Recovery program ...
Reinstall the Product Recovery Program? (Y/N) [ ]”.

Note: If the hard-disk drive contains any partitions, you

4. Enter Y. The Service Partition is created and loaded

5. At next window, press Enter to continue.

Install preloaded system from CD:

6. Boot with the Recovery CD (and the boot diskette if

7. If the hard-disk drive is blank, the following message

8. If you get a message asking which operating system

9. A message appears: “Full Recovery:”. Press Enter to

10. Enter the Y at each of the next three windows.

11. Follow the prompts to complete Recovery.

do not receive this message ; go to step 1.

with the Product Recovery program files.
Note: If you do not want to create the Service

Partition, press N key, and then go to step 8.

v The Service Partition is created. The system

automatically reboots during this process.

v The recovery process copies some files to the

Service Partition and, PKUNZIPs others.

v Follow the prompts. You may be prompted to

change CDs.

v When the process is complete, the system reboots.

Continue to step 6 to install preloaded system.

required.)

appears: “Your computer originally included a

Product Recovery program ... Reinstall the
Product Recovery Program? (Y/N) [ ]”.

v To install the Service Partition, go to step 4.
v To preload the hard-disk drive without installing the

Service Partition, press the N key.

to install, highlight the proper operating system and
press Enter.

select.

To create a recovery repair diskette

If the prompt needed for access to the Product Recovery
program does not appear, you can recover it by use of the
Recovery Repair diskette. Make a Recovery Repair
diskette and save it for future use. To make a Recovery
Repair diskette:

1. Shut down and turn off the computer.

2. Attach the external diskette drive to the computer.

3. At the prompt, press F11. (The option to press F11
appears for only a few seconds. You must press F11
quickly.) The Product Recovery program main menu
appears.

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

Related service information

4. If you are using Windows 2000 Professional, you are
prompted to select an operating system. This menu
does not appear for Windows 98 SE.

5. From the main menu, select System Utilities. Press
Enter.

6. Select Create a Recovery Repair diskette. Press Enter.

7. Follow the on-screen instructions.

8. When the process is completed, label the diskette as
the Recovery Repair diskette and save it for future use.

To use the recovery repair diskette:

1. Shut down and turn off the computer.

2. Attach the external diskette drive to the computer.

3. Insert the Recovery Repair diskette into the drive; then
turn on the computer.

4. Follow the on-screen instructions.

Passwords

As many as three passwords may be needed for any
ThinkPad computer: the power-on password (POP), the
hard-disk password (HDP), and the supervisor password
(SVP).

If any of these passwords has been set, a prompt for it
appears on the screen whenever the computer is turned
on. The computer does not start until the password is
entered.

Exception: If only an SVP is installed, the password

prompt doesn’t appear when the operating
system is booted.

Power-on password:

A power-on password (POP) protects the system from
being powered on by an unauthorized person. The
password must be entered before an operating system can
be booted.

Hard-disk password:

There are two hard-disk passwords (HDPs):

v User HDP—for the user
v Master HDP—for the system administrator, who can use

it to get access to the hard disk even if the user has
changed the user HDP

Note: There are two modes for the HDP: User only and

Master + User. The Master + User mode requires

two HDPs; the system administrator enters both in
the same operation. The system administrator then
provides the user HDP to the system user.

General descriptions 25

Related service information

Attention

If the user HDP has been forgotten, check whether
a master HDP has been set. It it has, it can be used
for access to the hard-disk drive. If no master HDP
is available, IBM does not provide any services to
reset either the user or the master HDP, or to
recover data from the hard-disk drive. The hard-disk
drive can be replaced for a scheduled fee.

Supervisor password:

A supervisor password (SVP) protects the system
information stored in the IBM BIOS Setup Utility. The SVP
must be entered in order to get access to the IBM BIOS
Setup Utility and make changes to system configuration
settings.

Attention

If the SVP has been forgotten and cannot be made
available to the servicer, there is no service
procedure to reset the password. The systemboard
must be replaced for a scheduled fee.

How to remove the power-on password

To remove a POP that you have forgotten, do the
following:

(A) If no SVP has been set:

1. Turn off the computer.

2. Remove the battery pack.
For how to remove the battery pack, see “1010 Battery

pack” on page 58.

3. Remove the backup battery.
For how to remove the backup battery, see “1020

Backup battery” on page 59.

4. Turn on the computer and wait until the POST ends.
After the POST ends, the password prompt does not

appear. The POP has been removed.

5. Reinstall the backup battery and the battery pack.

(B) If an SVP has been set and is known by the servicer:

1. Turn on the computer by pressing and holding F1.

2. Enter the SVP. The IBM BIOS Setup Utility menu
appears.

3. Select Password, using the cursor keys to move down
the menu.

4. Select Power-On Password.

5. At the Enter Current Password field, enter the SVP.

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

Related service information

6. When the Enter New Password field opens, leave it
blank and press Enter twice.

7. In the Changes have been saved window, press Enter.

8. Press F10; then, in the Setup confirmation window,
select Yes .

How to remove the hard-disk password

Attention

If User only mode is selected and the user HDP
has been forgotten and cannot be made available to
the servicer, IBM does not provide any services to
reset the user HDPs or to recover data from the
hard-disk drive. The hard-disk drive can be replaced
for a scheduled fee.

To remove a user HDP that has been forgotten, when the
SVP and the master HDP are known, do the following:

1. Power on the computer by pressing and holding F1.

2. Enter the SVP. The IBM BIOS Setup Utility menu
appears.

3. Select Password, using the cursor keys to move down
the menu.

4. Select Hard-disk x password, where x is the letter of
the hard-disk drive. A pop-up window opens.

5. Select either User HDP or Master HDP.

6. Enter the master HDP; then leave the New Password
field blank and press Enter twice.

7. Press F10.

8. Select Yes in the Setup Configuration window.
Both user HDP and master HDP will have been

removed.

Power management

To reduce power consumption, the computer has three
power management modes: screen blank, standby, and
hibernation.

Notes

v Screen blank mode is called standby mode in

Windows 95 and Windows NT.

v Standby mode is called suspend mode in

Windows 95 and Windows NT.

Screen blank mode

Screen blank mode has three variants, as follows:

1. If you press Fn + F3, or the time set on the “LCD off
timer” in IBM BIOS Setup Utility expires,
v The LCD backlight turns off.

General descriptions 27

Related service information

v The hard-disk drive motor stops.
v The speaker is muted.

2. If you are using the ACPI operating system and you
press Fn + F3,

v The LCD backlight turns off.
v The hard-disk drive motor stops.

3. If the time set on the “Turn off monitor” timer in the
operating system expires,
v The LCD backlight turns off.

To end screen blank mode and resume normal operation,
press any key.

Standby mode

When the computer enters standby mode, the following
events occur in addition to what occurs in screen blank
mode:

v The LCD is powered off.
v The hard-disk drive is powered off.
v The CPU stops.

To enter standby mode, press Fn + F4.
Note: You can change the action of Fn + F4, if you are

using the ACPI operating system.

In certain circumstances, the computer goes into standby
mode automatically:
v If a “suspend time” has been set on the timer, and the

user does not do any operation with the keyboard, the
TrackPoint, the hard disk, the parallel connector, or the
diskette drive within that time.

v If the battery indicator blinks orange, indicating that the

battery power is low. (Alternatively, if Hibernate when
battery becomes low has been selected in the “Power
Management Properties” window, the computer goes
into hibernation mode.)

Note for the APM operating system:

Even if you do not set the low-battery alarm, the charge
indicator notifies you when the battery is low, and then the
computer enters the power-saving mode automatically.
This default low-battery behavior is independent of the
operating system; so if you have set the low-battery alarm,
the computer may not do what you specified. It chooses
either your setting or the default setting, whichever is
appropriate.

If you are using the ACPI operating system, only the
low-battery alarm is available.

To cause the computer to return from standby mode and
resume operation, do one of the following:
v Press the Fn key.

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

Related service information

v Open the LCD cover (only if you are using Windows Me

and you entered standby mode by closing the LCD

cover).
v Turn on the power switch.
Also, the computer automatically returns from standby
mode and resumes operation in either of the following
events:
v The ring indicator (RI) is signaled by a serial device or a

PC Card device (Windows 2000 does not support the

ring indicator (RI) resume by PC Card device.)
v The time set on the resume timer elapses. In Windows

98, the Scheduled Tasks setting takes priority over the

Resume on timer selection in the “Power Management

Properties” window.

Note: The computer does not accept any input

immediately after it enters standby mode. Wait a
few seconds before taking any action to reenter
operation mode.

Hibernation mode

Note for Windows NT

If you are using Windows NT in the default format,
NTFS, you cannot create a hibernation file. If you
want to use hibernation mode, you will need to
reinstall Windows NT with FAT format.

Note for OS/2

If you are using OS/2 in the default format, HPFS,
you cannot create a hibernation file. If you want to
use hibernation mode, you will need to reinstall
OS/2 with FAT format.

In hibernation mode, the following occurs:
v The system status, RAM, VRAM, and setup data are

stored on the hard disk.
v The system is powered off.

Note: If the computer enters the hibernation mode while it

is docked to the docking station, do not undock it
from the docking station before resuming normal
operation. If you do undock it and then try to
resume normal operation, you will get an error
message, and you will have to restart the system.

To cause the computer to enter hibernation mode, do any
of the following:
v Press the Fn + F12 keys.

General descriptions 29

Related service information

v If you are using the APM operating system and have set

the mode to Power switch mode [Hibernation], turn
off the power switch.

v If you are using the ACPI operating system and have

defined one of the following actions as the event that
causes the system to go into hibernation mode, perform
that action.

– Closing the lid.
– Pressing the power button.
– Pressing Fn + F4 keys.

Also, the computer goes into hibernation mode
automatically in either of the following conditions:
v If a “hibernation time” has been set on the timer, and the

user does not do any operation with the keyboard, the
TrackPoint, the hard-disk drive, the parallel connector, or
the diskette drive within that time.

v If the timer conditions are satisfied in suspend mode.
v If you are using the APM operating system and have set

the mode to Hibernate when battery becomes low,
and the battery charge becomes critically low.

When the power is turned on, the computer returns from
hibernation mode and resumes operation. The hibernation
file in the boot record on the hard-disk drive is read, and
system status is restored from the hard-disk drive.

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

Checkout guide

Checkout guide

Use the following procedures as a guide in identifying and
correcting problems with the ThinkPad computer.

Note: The diagnostic tests are intended to test only IBM

products. The use of non-IBM products, prototype
cards, or modified options can lead to false
indications of errors and invalid system responses.

1. Identify the failing symptoms in as much detail as

possible.

2. Verify the symptoms. Try to re-create the failure by

running the diagnostic test or by repeating the
operation.

Testing the computer

The ThinkPad computer has a test program called
PC-Doctor®DOS (hereafter called PC-Doctor). You can
detect errors by running the diagnostics test included in
PC-Doctor. This section is an overview of the procedure.
For details that depend on model-unique functions, refer to
“Product overview” on page 39.

For some possible configurations of the computer,
PC-Doctor might not run correctly. To avoid this problem,
you need to initialize the computer setup by use of the IBM
BIOS Setup Utility before you run PC-Doctor. On the IBM
BIOS Setup Utility screen, press F9, Enter, F10, and then
Enter.

Note: When you initialize the computer configuration,

some devices are disabled, such as the serial port.
If you test one of these devices, you will need to
enable it by using PS2.EXE.

PC-Doctor cannot be used to test a device that is in the
docking station, even if the computer supports the docking
station. To test a USB device, connect it to the USB
connector of the computer. To test the Ultrabay 2000
device, install it in the Ultrabay 2000 slot of the computer.

To run the test, do as follows:
Note: In the following procedure, you can select an item

not only with the arrow keys, but also with the
TrackPoint. Instead of pressing Enter, click the left
button.

1. Insert the PC-Doctor disk into the diskette drive; then

power on the computer.
If the computer cannot be powered on, go to “Power

system checkout” on page 34, and check the power
sources.

General descriptions 31

Checkout guide

If an error code appears, go to “Symptom-to-FRU
index” on page 47.

On the first screen, select the model and press Enter.
Follow the instructions on the screen.

2. The main panel of PC-Doctor appears.

3. Select Diagnostics with the arrow keys, and press
Enter.

A pull-down menu appears. (Its exact form depends on
the model.)

The options on the test menu are as follows:

Diagnostics Interactive Tests

v Run Normal Test
v Run Quick Test
v CPU/Coprocessor
v Systemboard
v Video Adapter
v Serial Ports
v Parallel Ports
v Fixed Disks
v Diskette Drives
v Other Devices
v ZIP Drive
v LS-120 Drive
v Communication
v Wireless LAN(*)
v Memory Test – Full
v Memory Test – Quick

Notes:

v In the Keyboard test in Interactive Tests, the Fn key

is scanned only once. Each key should be held down
for at least 2 seconds; otherwise, it cannot be sensed.

v The sound card is not recognized in the Stereo

Speaker in the Interactive Tests. To test it, use the
audio device test in the Other Devices in
Diagnostics.

v Video Adapter test supports only the LCD display on

ThinkPad. Before running PC-Doctor DOS, detach the
external Monitor.

v To test ZIP Drive or LS-120 Drive, each media is

needed to be inserted before start testing.

v Wireless LAN test and 802.11 Wireless Radio Test is

only for some models. Some models do not have
them.

v To test Digital Signature Chip, the chip must be

enabled and initialized.

v Keyboard
v Video
v Internal Speaker
v Mouse
v Joystick Test
v Diskette
v System Load
v CD-ROM/DVD Test
v Stereo Speaker
v 802.11 Wireless Radio

Test(*)

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

Checkout guide

Diagnostics

Memory Test - Full
Memory Test - Quick

Use the cursor keys and ESC to move in menus. Press ENTER to select.

InteractiveTests

Run NormalTest

Run QuickTest
CPU/Coprocessor
Systemboard
Video Adapter
Serial Ports
Parallel Ports
Fixed Disks
Diskette Drives
Other Devices
Communication

PC-DOCTOR 2.0 Copyright 2000 PC-Doctor, Inc. All Rights Reserved.

Hardware Info

Utility F1=Help

Quit

4. Run the applicable function test.

5. Follow the instructions on the screen. If there is a
problem, PC-Doctor shows messages describing it.

6. To exit the test, select Quit — Exit Diag.
To cancel the test, press Esc.

Note: After executing PC-Doctor, check the system

time/date and reset them if needed.

Detecting system information with PC-Doctor

PC-Doctor can detect the following system information:

Hardware Info

v System Configuration
v Memory Contents
v Physical Disk Drives
v Logical Disk Drives
v VGA Information
v IDE Drive Info
v PCI Information
v PNPISA Info
v SMBIOS Info
v VESA LCD Info

Utility

v Run External Tests
v Surface Scan Hard Disk
v Benchmark System
v DOS Shell
v Tech Support Form
v Battery Rundown
v View Test Log
v Print Log
v Save Log
v Full Erase Hard Drive
v Quick Erase Hard Drive

General descriptions 33

Checkout guide

Power system checkout

To verify a symptom, do the following:

1. Power off the computer.

2. Remove the battery pack.

3. Connect the ac adapter.

4. Check that power is supplied when you power on the
computer.

5. Power off the computer.

6. Disconnect the ac adapter and install the charged
battery pack.

7. Check that the battery pack supplies power when you
power on the computer.

If you suspect a power problem, see the appropriate one
of the following power supply checkouts:

v “Checking the ac adapter”
v “Checking operational charging” on page 35
v “Checking the battery pack” on page 35
v “Checking the backup battery” on page 36

Checking the ac adapter

You are here because the computer fails only when the ac
adapter is used:
v If the power problem occurs only when the port

replicator is used, replace the port replicator.

v If the power-on indicator does not turn on, check the

power cord of the ac adapter for correct continuity and
installation.

v If the computer does not charge during operation, go to

“Checking operational charging”.

To check the ac adapter, do the following:

1. Unplug the ac adapter cable from the computer.

2. Measure the output voltage at the plug of the ac
adapter cable. See the following figure:

Pin Voltage (V dc)

2

1

(16-10V)

3. If the voltage is not correct, replace the ac adapter.

4. If the voltage is acceptable, do the following:

v Replace the system board.
v If the problem persists, go to “Product overview” on

page 39.

Note: Noise from the ac adapter does not always indicate

a defect.

1 +15.5 to +17.0
2 Ground

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

Checkout guide

Checking operational charging

To check whether the battery charges properly during
operation, use a discharged battery pack or a battery pack
that has less than 50% of the total power remaining when
installed in the computer.

Perform operational charging. If the battery status indicator
or icon does not turn on, remove the battery pack and let it
return to room temperature. Reinstall the battery pack. If
the charge indicator or icon still does not turn on, replace
the battery pack.

If the charge indicator still does not turn on, replace the
system board. Then reinstall the battery pack. If it is still
not charged, go to the next section.

Checking the battery pack

Battery charging does not start until the Power Meter
shows that less than 95% of the total power remains;
under this condition the battery pack can charge to 100%
of its capacity. This protects the battery pack from being
overcharged or from having a shortened life.

To check the status of your battery, move your cursor to
the Power Meter icon in the icon tray of the Windows
taskbar and wait for a moment (but do not click), and the
percentage of battery power remaining is displayed. To get
detailed information about the battery, double-click the
Power Meter icon.

Note: If the battery pack becomes hot, it may not be able

to charge. Remove it from the computer and leave it
at room temperature for a while. After it cools down,
reinstall and recharge it.

To check the battery pack, do the following:

1. Power off the computer.

2. Remove the battery pack and measure the voltage
between battery terminals 1 (+) and 5 (−). See the
following figure:

Terminal Voltage (V dc)

1(+)

2

3

4

5(-)

3. If the voltage is less than +11.0 V dc, the battery pack
has been discharged.

1 + 0 to + 12.6
5 Ground (−)

General descriptions 35

Checkout guide

Note: Recharging will take at least 3 hours, even if the

indicator does not turn on.

If the voltage is still less than +11.0 V dc after
recharging, replace the battery.

4. If the voltage is more than +11.0 V dc, measure the
resistance between battery terminals 4 and 5. The
resistance must be 4 to 30 K .

If the resistance is not correct, replace the battery
pack. If the resistance is correct, replace the system
board.

Checking the backup battery

Do the following:

1. Power off the computer, and unplug the ac adapter
from it.

2. Turn the computer upside down.

3. Remove the battery pack (see “1010 Battery pack” on
page 58).

4. Remove the backup battery (see “Checking the battery
pack” on page 35).

5. Measure the voltage of the backup battery. See the
following figure.

Red (+)

Black (-)

v If the voltage is correct, replace the system board.
v If the voltage is not correct, replace the backup battery.
v If the backup battery discharges quickly after

replacement, replace the system board.

Wire Voltage (V dc)

Red +2.5 to +3.2
Black Ground

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

ThinkPad T20, T21, T22 and T23 series

Product overview ............39

Specifications ............39

Status indicators ...........42

FRU Tests .............44

Fn key combinations ..........46

Symptom-to-FRU index ..........47

Numeric error codes ..........47

Error messages ...........50

Beep symptoms ...........51

No beep symptoms ..........51

LCD-related symptoms .........52

Intermittent problems ..........53

Undetermined problems .........53

FRU replacement notices .........54

Screw notices ............54

Retaining serial numbers.........55

Restoring the serial number of the system unit 55

Retaining the UUID .........55

Removing and replacing a FRU........57

1010 Battery pack...........58

1020 Backup battery ..........59

1030 Hard-disk drive ..........61

1040 DIMM ............63

1050 Mini PCI adapter .........64

For T20, T21 and T22 series ......64

For T23 series...........66

1060 Ethernet daughter card .......68

1070 Ultrabay 2000 device ........71

1080 Keyboard ...........72

For T20, T21 and T22 series ......72

For T23 series...........73

1090 Keyboard CRU insulator .......80

1100 Hinge cover ...........81

For T20 and T21 series ........82

For T22 series...........83

For T23 series...........85

1110 Keyboard bezel ..........86

For T20, T21 and T22 series ......86

For T23 series...........88

1120 Fan assembly ..........92

For T20, T21, T22 series........92

For T23 series...........94

1130CPU.............97

For T20, T21 and T22 series ......97

For T23 series...........98

1140 PC Card slot assembly .......99

For T20, T21, T22 series........99

For T23 series ..........101

1150 Speaker ...........102

© Copyright IBM Corp. 2001

37

1160 Hard-disk bay ..........104

1170 Ultrabay 2000 slot ........106

For T20 series ..........106

For T21 and T22 series........107

For T23 series ..........108

1180 System board ..........113

For T20, T21, T22 series .......113

For T23 series ..........115

1190 Secure chip ..........117

1200 Microphone cable.........118

2010 LCD assembly..........119

2020 Front bezel...........122

2030 Inverter card ..........123

2040 LCD panel ...........124

2050 Antenna assembly ........128

2060 Sub card ...........131

3010 ThinkPad Dock PCI cover ......133

3020 ThinkPad Dock top cover ......135

Locations ..............140

Front view ............140

Rear view.............141

Bottom view ............142

Parts list ..............143

T20, T21, T22 and T23 series model matrix 143

Overall .............146

For T20, T21 and T22 ........146

ForT23............151

LCD FRUs ............154

13.3-in. XGA TFT .........154

14.1-in. XGA TFT .........155

14.1-in. SXGA+ TFT ........155

Keyboard .............156

Recovery CDs for T22 series .......157

Windows 98 recovery CDs.......157

Windows 2000 recovery CDs ......158

Windows 2000/Windows NT recovery CDs 158

Recovery CDs for T23 series .......159

Windows 98 recovery CDs.......159

Windows 2000 recovery CDs ......160

Windows 2000/Windows NT recovery CDs 160

Miscellaneous parts ..........161

Optional FRUs ...........167

Common parts list ..........168

Tools .............168

Power cords (system) ........168

Power cords (docking station) ......169

Notices ..............170

Trademarks ............170

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

Product overview

Product overview

This section presents the following product-unique
information:

v “Specifications”
v “Status indicators” on page 42
v “FRU Tests” on page 44
v “Fn key combinations” on page 46

Specifications

The following table lists the specifications of the ThinkPad
T20, T21, T22 and T23 series:

Feature Description
Processor T20

v Mobile Intel
v Mobile Intel
v Mobile Intel®Pentium®III processor 750 MHz

T21

v Mobile Intel
v Mobile Intel
v Mobile Intel®Pentium®III processor 850 MHz

T22

v Mobile Intel
v Mobile Intel
v Mobile Intel®Pentium®III processor 1 GHz

T23

v Mobile Intel

MHz-M

v Mobile Intel

GHz-M

Bus
architecture

Memory
(standard)

PCI Bus

T20, T21, T22

v 128 MB (PC100) (on the system board)

T23

v 128 MB (PC133) (on the system board)

Memory
(optional)

T20, T21, T22

v 64 MB, 128 MB, or 256 MB DIMM card

(maximum of 512 MB)

T23

v 64 MB, 128 MB, 256 MB, or 512 MB DIMM

card (maximum of 1024 MB)

CMOS RAM 242 bytes

®

Pentium®III processor 650 MHz

®

Pentium®III processor 700 MHz

®

Pentium®III processor 750 MHz

®

Pentium®III processor 800 MHz

®

Pentium®III processor 800 MHz

®

Pentium®III processor 900 MHz

®

Pentium®III processor 866

®

Pentium®III processor 1.13

(continued)

ThinkPad T20, T21, T22 and T23 series 39

Feature Description

Display T20

Hard-disk drive T20

I/O port v External monitor

v 13.3-inch, 16M colors, XGA (1024 × 768

resolution) TFT color LCD

v 14.1-inch, 16M colors, XGA (1024 × 768

resolution) TFT color LCD

T21, T22, T23

v 13.3-inch, 16M colors, XGA (1024 × 768

resolution) TFT color LCD

v 14.1-inch, 16M colors, XGA (1024 × 768

resolution) TFT color LCD

v 14.1-inch, 16M colors, SXGA+ (1400 × 1050

resolution) TFT color LCD

v 6.0 GB, 2.5-inch, IDE interface
v 12.0 GB, 2.5-inch, IDE interface
v 18.0 GB, 2.5-inch, IDE interface
v 20.0 GB, 2.5-inch, IDE interface

T21, T22

v 10.0 GB, 2.5-inch, IDE interface
v 20.0 GB, 2.5-inch, IDE interface
v 32.0 GB, 2.5-inch, IDE interface

T23

v 15.0 GB, 2.5-inch, IDE interface
v 48.0 GB, 2.5-inch, IDE interface

v Line-in
v Headphone
v Microphone
v Mouse or keyboard
v Parallel or diskette drive
v Port replicator connector
v Serial
v One universal serial bus (USB) connector for

T20, T21, and T22 series

v Two USB connectors for T23
v RJ11
v RJ45 (covered)
v TV-out

Product overview

(continued)

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

Feature Description

Internal
modem

Audio v Internal microphone

Infrared
transfer

802.11b (only
for T23 series)

PC Card One Type-III or two Type-II
AC adapter 72-watt type
Bay device T20

56.6 Kbps

v Internal speaker
v Software control volume

IrDA 1.1

Mini PCI Type-IIIa IEEE 802.11b wireless LAN
card

v 1.44 MB (3-mode), 3.5-inch diskette drive
v 10-24x CD-ROM drive
v 6x DVD-ROM drive

T21, T22, T23

v 1.44 MB (3-mode), 3.5-inch diskette drive
v 10-24x CD-ROM drive
v 8x DVD-ROM drive

Product overview

ThinkPad T20, T21, T22 and T23 series 41

Product overview

Status indicators

The system status indicators show the status of the
computer, as follows:

1 2 3 4 5

6 7 8

Indicator Meaning

1 Drive in use Green: Data is being read from or written

to the hard-disk drive, the diskette
drive, or the drive in the Ultrabay

2000. When this indicator is on, do
not put the computer into standby
mode or turn off the computer.

Note: Do not move the system while the
Green drive in use light is on. Sudden physical
shock could cause drive errors.

2 Num lock Green: The numeric keypad on the

3 Caps lock Green: Caps Lock mode is enabled. To

keyboard is enabled. To enable or
disable the keypad, press and hold
the Fn key while pressing the
NumLk key.

enable or disable Caps Lock
mode, press Fn + Caps Lock key.

(continued)

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

Product overview

Indicator Meaning

4 Scroll lock Green: Scroll Lock mode is enabled. Arrow

keys can be used as screen-scroll
function keys, but not to move the
cursor. To enable or disable Scroll
Lock mode, press Fn + ScrLk key.
Not all application programs
support this function.

5 Power on Green: This indicator stays lighted

6 Battery Green: The battery is fully charged.

7 Standby

status

8 Ultrabay
status

Blinking green:

Orange: The battery power is low. The

Blinking orange:

Green: The computer is in standby mode.
Blinking green:

Green: An Ultrabay 2000 device is

Blinking green:

Turn off: An Ultrabay 2000 device is ready

whenever the computer is on. If
the power-on indicator is on and
the standby indicator is off, the
system is ready to use. If both the
power-on indicator and the standby
indicator are on, you can use the
computer after it returns from the
standby mode and the standby
indicator goes off.

The battery has enough power to
operate, but is being charged.

battery needs to be charged.

The battery needs to be charged
when the indicator starts blinking
orange, the computer beeps three
times.

The computer is entering standby
mode or hibernation mode, or is
resuming normal operation. This
indicator does not blink in Windows
2000 and Windows Me.

installed and in use.

An Ultrabay 2000 device is in the
process of being detached.

to be attached or detached.

Note: If you are using Windows 2000, the
Ultrabay status indicator does not blink while
an Ultrabay 2000 device is being detached.
Instead, a message box pops up when the
process is completed; then the indicator turns
off.

ThinkPad T20, T21, T22 and T23 series 43

Product overview

FRU Tests

The following table shows the test for each FRU.

FRU Applicable test

System board 1. Diagnostics --> CPU/Coprocessor

Power Diagnostics --> Other Devices --> IBM AC

LCD unit 1. Diagnostics --> Video Adapter

Modem 1. Make sure the modem is set up correctly.

Audio 1. Interactive Tests --> Internal Speaker

Speaker Interactive Tests --> Internal Speaker
PC Card slots Diagnostics --> Systemboard --> PCMCIA,

Keyboard 1. Diagnostics --> Systemboard -->

TrackPoint or
pointing device

Hard-disk drive Diagnostics --> Fixed Disks

2. Diagnostics --> Systemboard

Adapter, IBM Battery 1 (IBM Battery 2)

2. Interactive Tests --> Video

2. Replace the modem jack and the modem
card in turn, and run the following test in
Diagnostics --> Communication:
a. Lucent Modem (M2) Loopback
b. Lucent Modem (M2) Dialtone/DTM
c. Lucent Soft Modem Loopback (M2)

(T23 only)
d. Lucent Soft Modem Dialtone (T23 only)
e. Intel Modem Register
f. Intel Modem Loopback/DTMF
g. Intel SP Modem Register
h. Intel SP Modem Loopback/DTMF
i. 3Com MiniPCI Modem Test
j. 3Com MiniPCI Dialtone Test

2. Diagnostics --> Other Devices --> Crystal

SoundFusion

PCMCIA External Loop

Keyboard

2. Interactive Tests --> Keyboard
If the TrackPoint does not work, check the

configuration in the ThinkPad Configuration
program. If the TrackPoint is disabled, select
Enable to enable it.

After you use the TrackPoint, the pointer may
drift on the screen for a short time. This drift
can occur when a slight, steady pressure is
applied to the TrackPoint pointer. This symptom
is not a hardware problem. If the pointer stops
after a short time, no service action is
necessary.

If enabling the TrackPoint does not correct the
problem, continue with the following:
v Interactive Tests --> Mouse

™

Test

(continued)

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

Product overview

FRU Applicable test

Diskette drive 1. Diagnostics --> Diskette Drives

CD-ROM or
DVD drive

Memory 1. If two DIMMs are installed, remove one of

Fan 1. Turn on the computer and check the air

2. Interactive Tests --> Diskette

1. Diagnostics --> Other Devices -->

CD-ROM/DVD

2. Interactive Tests --> CD-ROM/DVD Test

them and run Diagnostics --> Memory
Test - Quick.

2. If the problem does not recur, return the
DIMM to its place, remove the other one,
and run the test again.

3. If the test does not detect the error, run
Diagnostics --> Memory Test - Full.

turbulence at the louver near the power
switch.

2. Run Diagnostics --> Other Devices -->
IBM Fan.

ThinkPad T20, T21, T22 and T23 series 45

Product overview

Fn key combinations

The following table shows the function of each combination
of Fn with a function key.

The Fn key works independently from the operating
system.

Key
combination

Fn + F1 Reserved.
Fn + F2 Reserved.
Fn + F3 Turn off the LCD display, leaving the screen

Fn + F4 Turn standby mode on. To return to normal

Fn + F5 Reserved.
Fn + F6 Reserved.
Fn + F7 Switch between the LCD and an external

Fn + F8 Turn screen expansion on or off. (There is no

Fn + F9 Reserved.
Fn + F10 Reserved.
Fn + F11 Reserved.
Fn + F12 Turn hibernation mode on. To return to normal

Fn + PgUp Turn the ThinkLight on or off.
Fn + Home The LCD becomes brighter.
Fn + End The LCD becomes less bright.

Description

blank. To turn the LCD display on again, press
any key or the TrackPoint stick.

operation, press the Fn key independently,
without pressing a function key.

monitor (CRT). If an external monitor is
attached, computer output is displayed in the
following three patterns by turns:

v CRT display
v LCD + CRT display
v LCD

symbol on the key.)

operation, press the power button for less than
four seconds.

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

Symptom-to-FRU index

Symptom-to-FRU index

This section lists symptoms and errors and their possible
causes. The most likely cause is listed first, in boldface
type.

Note: Do the FRU replacement or other actions in the

sequence shown in the column headed “FRU or
action, in sequence.” If replacing a FRU does not
solve the problem, put the original part back in the
computer. Do not replace a nondefective FRU.

This index can also help you determine, during regular
servicing, what FRUs are likely to need to be replaced
next.

A numeric error is displayed for each error detected in
POST or system operation. In the displays, n can be any
number.

If no numeric code is displayed, check the narrative
descriptions of symptoms. If the symptom is not described
there, go to “Intermittent problems” on page 53.

Note

For an IBM device not supported by diagnostic
codes in the ThinkPad notebook computers, see the
manual for that device.

Numeric error codes

Symptom or error FRU or action, in sequence
0175

Bad CRC1, stop POST task —
The EEPROM checksum is not
correct.

0187

EAIA data access error — The
access to EEPROM has failed.

0188

Invalid RFID serialization
information area or bad CRC2
— The EEPROM checksum is
not correct.

0189

Invalid RFID configuration
information area — The
EEPROM checksum is not
correct.

(continued)

ThinkPad T20, T21, T22 and T23 series 47

System board.

System board.

System board.

System board.

Symptom-to-FRU index

Symptom or error FRU or action, in sequence
0190

Critical low battery error.

0193

RF antenna has been removed.

0194

The computer has been carried
through a security gate.

0195

Security hardware tamper
detected.

0196

Security hardware removed.

0197

Invalid Remote change
requested.

01C9

More than one Ethernet devices
are found — Remove one of
them. Press <Esc> to continue.

0200

Hard disk error — The hard
disk is not working.

021x

Stuck key — Keyboard error.

0220

Monitor type error — Monitor
type does not match the one
specified in CMOS.

1. Charge the battery pack.

2. Battery pack.

Enter the supervisor
password.

Enter the supervisor
password.

1. Enter IBM BIOS Setup

Utility by entering
supervisor password, and
select Password --> IBM
Security Chip --> Clear
IBM Security Chip to clear
this error.

2. Security Chip.

3. System board.

1. Enter IBM BIOS Setup

Utility by entering
supervisor password, and
select “Password” -->

“IBM Security Chip” -->
“Clear IBM Security Chip”

to clear this error.

2. Security Chip.

3. System board.
The remote configuration for

the security chip has failed.
Confirm the operation and try
again.

1. Remove either a Mini PCI

Ethernet card or an
Ethernet daughter card,
otherwise press Esc key
to ignore the warning
message.

2. System board.

1. Reseat the hard-disk
drive.

2. Load Setup Defaults in IBM
BIOS Setup Utility.

3. Hard-disk drive.

4. System board.

Run interactive tests of the
keyboard and the auxiliary
input device.

Load Setup Defaults in IBM
BIOS Setup Utility.

(continued)

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

Symptom-to-FRU index

Symptom or error FRU or action, in sequence
0230

Shadow RAM error — The
shadow RAM failure at offset
nnnn.

0231

System RAM error — System
RAM failure at offset nnnn.

0232

Extended RAM error —
Extended RAM failure at offset
nnnn.

0250

System battery error — System
battery is dead.

0251

System CMOS checksum
bad—Default configuration
used.

0252

Password checksum bad —
The password is cleared.

0260

System timer error.

0270

Real-time clock error.

0271

Date and time error — Neither
the date nor the time is set in
the computer.

02B2

Incorrect drive A type.

02F4

EISA CMOS not writable.

02F5

DIMM test failure.

02F6

Software NMI failure.

02F7

Fail-safe timer NMI failure.

System board.

1. DIMM.

2. System board.

1. DIMM.

2. System board.

Replace the backup battery
and run IBM BIOS Setup
Utility to reset the time and
date.

Replace the backup battery
and run IBM BIOS Setup
Utility to reset the time and
date.

Reset the password by
running IBM BIOS Setup
Utility.

1. Replace the backup

battery and run IBM BIOS
Setup Utility to reset the
time and date.

2. System board.

1. Replace the backup

battery and run IBM BIOS
Setup Utility to reset the
time and date.

2. System board.

Run IBM BIOS Setup Utility to
reset the time and date.

1. Diskette drive.

2. External FDD cable.

3. I/O card.

1. Load Setup Defaults in
IBM BIOS Setup Utility.

2. Replace the backup battery.

3. System board.

1. DIMM.

2. System board.

1. DIMM.

2. System board.

1. DIMM.

2. System board.

ThinkPad T20, T21, T22 and T23 series 49

Symptom-to-FRU index

Error messages

Symptom or error FRU or action, in sequence

Device address conflict. 1. Load Setup Defaults in

Allocation error for device. 1. Load Setup Defaults in

Failing bits: nnnn. 1. DIMM.

Invalid system configuration
data.

I/O device IRQ conflict. 1. Load Setup Defaults in

Operating system not found. 1. Check that the operating

Hibernation error. 1. Restore the system

Fan error. Fan.

IBM BIOS Setup Utility.

2. Backup battery.

3. System board.

IBM BIOS Setup Utility.

2. Backup battery.

3. System board.

2. System board.

1. DIMM.

2. System board.

IBM BIOS Setup Utility.

2. Backup battery.

3. System board.

system has no failure and is
installed correctly.

2. Enter IBM BIOS Setup

Utility and see whether
the hard-disk drive and
the diskette drive are
properly identified.

3. Reseat the hard-disk drive.

4. Reinstall the operating
system.

5. Diskette drive.

6. Hard-disk drive.

7. System board.

configuration to what it
was before the computer
entered hibernation mode.

2. If memory size has been
changed, re-create the
hibernation file.

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

Symptom-to-FRU index

Beep symptoms

Symptom or error FRU or action, in sequence

One beep and a blank,
unreadable, or flashing LCD.

One long and two short beeps,
and a blank or unreadable
LCD.

Two short beeps with error
codes.

Two short beeps with blank
screen.

Two or more beeps, or a
continuous beep. Operating
System starts successfully.

Three short beeps, pause,
three more short beeps, and
one short beep.

Only cursor appears. Reinstall operating system.

1. Reseat the LCD
connector.

2. LCD assembly.

3. External CRT.

4. System board.

1. System board.

2. LCD assembly.

3. DIMM.

POST error. See “Numeric
error codes” on page 47.

1. System board.

2. DIMM.

If a Mini PCI Ethernet card is
installed, confirm that Alert On
LAN 2 in IBM BIOS Setup
Utility is disabled.

1. DIMM.

2. System board

No beep symptoms

Symptom or error FRU or action, in sequence

No beep, power-on indicator
on, LCD blank, and no POST.

No beep, power-on indicator
on, and LCD blank during
POST.

The power-on password
prompt.

The hard-disk password
prompt.

The DOS full screen looks
smaller.

1. Make sure that every

connector is connected
tightly and correctly.

2. DIMM.

3. System board.

1. Reseat DIMM.

2. System board.

A power-on password or a
supervisor password is set.
Type the password and press
Enter.

A hard-disk password is set.
Type the password and press
Enter.

Start the ThinkPad
Configuration program and set
the Screen expansion
function.

ThinkPad T20, T21, T22 and T23 series 51

Symptom-to-FRU index

LCD-related symptoms

Important

The TFT LCD for the notebook computer contains
many thin-film transistors (TFTs). A small number of
dots that are missing, discolored, or always lighted
is characteristic of TFT LCD technology, but
excessive pixel problems can cause viewing
concerns. The LCD should be replaced if the
number of missing, discolored, or lighted dots in any
background is:
v XGA: 8 or more bright dots, 8 or more dark dots,

or a total of 9 or more bright and dark dots.

v SXGA+: 11 or more bright dots, 13 or more dark

dots, or a total of 16 or more bright and dark
dots.

v UXGA: 11 or more bright dots, 16 or more dark

dots, or a total of 16 or more bright and dark
dots.

Note: Bright dots means pixel is always on (white

or color.) Dark dots means pixel is always off
(black color.)

Symptom or error FRU or action, in sequence

No beep, power-on indicator
on, and a blank LCD during
POST.

v LCD backlight not working.
v LCD too dark.
v LCD brightness cannot be

adjusted.

v LCD contrast cannot be

adjusted.

v LCD screen unreadable.
v Characters missing pixels.
v Screen abnormal.
v Wrong color displayed.

Horizontal or vertical lines
displayed on LCD.

System board.

1. Reseat the LCD
connectors.

2. LCD assembly.

3. System board.

1. See important note for

“LCD-related symptoms”.

2. Reseat all LCD connectors.

3. LCD assembly.

4. System board.

LCD assembly.

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

Symptom-to-FRU index

Intermittent problems

Intermittent system hang problems can be due to a variety
of causes that have nothing to do with a hardware defect,
such as cosmic radiation, electrostatic discharge, or
software errors. FRU replacement should be considered
only when a problem recurs.

When analyzing an intermittent problem, do the following:

1. Run the diagnostic test for the system board in loop
mode at least 10 times.

2. If no error is detected, do not replace any FRUs.

3. If any error is detected, replace the FRU shown by the
FRU code. Rerun the test to verify that no more errors
exist.

Undetermined problems

You are here because the diagnostic tests did not identify
which adapter or device failed, wrong devices are installed,
a short circuit is suspected, or the system is inoperative.
Follow these procedures to isolate the failing FRU (do not
isolate FRUs that have no defects).

Verify that all attached devices are supported by the
computer.

Verify that the power supply being used at the time of the
failure is operating correctly. (See “Power system
checkout” on page 34.)

1. Power off the computer.

2. Visually check each FRU for damage. Replace any
damaged FRU.

3. Remove or disconnect all of the following devices:
a. Non-IBM devices
b. Devices attached to the port replicator
c. Printer, mouse, and other external devices
d. Battery pack
e. Hard-disk drive
f. External diskette drive
g. DIMM
h. CD-ROM and diskette drive in the UltraslimBay
i. PC Cards

4. Power on the computer.

5. Determine whether the problem has changed.

6. If the problem does not recur, reconnect the removed
devices one at a time until you find the failing FRU.

7. If the problem remains, replace the following FRUs one
at a time (do not replace a nondefective FRU):
a. System board
b. LCD assembly

ThinkPad T20, T21, T22 and T23 series 53

FRU replacement notices

FRU replacement notices

This section contains notices related to removing and
replacing parts. Read this section carefully before replacing
any FRU.

Screw notices

Loose screws can cause a reliability problem. In IBM
ThinkPad computer, this problem is addressed with special
nylon-coated screws that have the following characteristics:

v They maintain tight connections.
v They do not easily come loose, even with shock or

vibration.

v They are harder to tighten.
v They should be used only once.

Do the following when you service this machine:
v Keep the screw kit (for the P/N, see “Miscellaneous

parts” on page 161) in your tool bag.

v Always use new screws.
v Use a torque screwdriver if you have one.

Tighten screws as follows:

v Plastic to plastic

Turn an additional 90 degrees after the screw head
touches the surface of the plastic part:

90 degrees more

(Cross-section)

v Logic card to plastic

Turn an additional 180 degrees after the screw head
touches the surface of the logic card:

180 degrees more

(Cross-section)

v Torque driver

If you have a torque driver, refer to the “Torque” column
for each step.

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

FRU replacement notices

v Make sure you use the correct screw. If you have a

torque screwdriver, tighten all screws firmly to the torque
shown in the table. Never use a screw that you

removed. Use a new one. Make sure the screws are
tightened firmly.

Retaining serial numbers

This section includes the following descriptions:

v “Restoring the serial number of the system unit”
v “Retaining the UUID”

Restoring the serial number of the system unit

When the computer was manufactured, the EEPROM on
the system board was loaded with the serial numbers of
the system and all major components. These numbers
need to remain the same throughout the life of the
computer.

If you replace the system board, you must restore the
serial number of the system unit to its original value.

Before replacing the system board, save the original serial
number by doing the following:

1. Install the ThinkPad hardware maintenance diskette
version 1.62, and restart the computer.

2. From the main menu, select 1. Set System
Identification.

3. Select 2. Read S/N data from EEPROM.

The serial number for each device is displayed. Write
down the serial number of the system unit, designated as
follows:

20: System unit serial number

After you have replaced the system board, restore the
serial number by doing the following:

1. Install the ThinkPad hardware maintenance diskette
version 1.62 and restart the computer.

2. From the main menu, select 1. Set System
Identification.

3. Select 1. Add S/N data from EEPROM.
Follow the instructions on the screen.

Note: The serial number of the system unit is written on

the label attached on the bottom of the computer.

Retaining the UUID

The Universally Unique Identifier (UUID) is a 128-bit
number uniquely assigned to your computer at production
and stored in the EEPROM of your system board. The
algorithm that generates the number is designed to provide

ThinkPad T20, T21, T22 and T23 series 55

FRU replacement notices

unique IDs until the year A.D. 3400. No two computers in
the world have the same number.

When you replace the system board, you must set the
UUID on the new system board as follows:

1. Install the ThinkPad hardware maintenance diskette
version 1.62, and restart the computer.

2. From the main menu, select 4. Assign UUID.
A new UUID is created and written. If a valid UUID

already exists, it is not overwritten.

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

Removing and replacing a FRU

Removing and replacing a FRU

This section presents directions and drawings for use in
removing and replacing a FRU. Be sure to observe the
following general rules:

1. Do not try to service any computer unless you have
been trained and certified. An untrained person runs
the risk of damaging parts.

2. Before replacing any FRU, review “FRU replacement
notices” on page 54.

3. Begin by removing any FRUs that have to be removed
before the failing FRU. Any such FRUs are listed at the
top of the page. Remove them in the order in which
they are listed.

4. Follow the correct sequence in the steps for removing
the FRU, as indicated in the drawings by the numbers
in square callouts.

5. When turning a screw to replace a FRU, turn it in the
direction indicated by the arrow in the drawing.

6. When removing the FRU, move it in the direction
indicated by the arrow in the drawing.

7. To put the new FRU in place, reverse the removal
procedure and follow any notes that pertain to
replacement. For information about connecting and
arranging internal cables, see “Locations” on page 140.

8. When replacing a FRU, use the correct screw as
shown in the procedures.

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.

Attention: Before the computer is powered on after FRU

replacement, make sure that all screws, springs, and other
small parts are in place and are not loose inside the
computer. Verify this by shaking the computer gently and
listening for rattling sounds. Metallic parts or metal flakes
can cause electrical short circuits.

Attention: The system board is sensitive to, and can be
damaged by, electrostatic discharge. Before touching it,
establish personal grounding by touching a ground point
with one hand or by using an electrostatic discharge (ESD)
strap (P/N 6405959).

ThinkPad T20, T21, T22 and T23 series 57

Removing and replacing a FRU

1010 Battery pack

DANGER:

Use only the battery in the parts listing for your
computer. Use of an incorrect battery can result in
ignition or explosion of the battery.

2

1

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

Removing and replacing a FRU

1020 Backup battery

DANGER:

Use only the battery in the parts listing for your
computer. Use of an incorrect battery can result in
ignition or explosion of the battery.

For access, remove this FRU:
v “1010 Battery pack” on page 58

1

2

Step Screw (quantity) Torque

1 M2.5 × 3.5 mm, (1) 39.2 Ncm

(4 kgfcm)

(continued)

ThinkPad T20, T21, T22 and T23 series 59

Removing and replacing a FRU

Cable routing: When attaching the backup battery to the

holder, route the battery cable as in the
following figure.

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

Removing and replacing a FRU

1030 Hard-disk drive

Attention

Do not drop or apply any shock to the hard-disk
drive. The hard-disk drive is sensitive to physical

shock. Incorrect handling can cause damage and
permanent loss of data.

Before removing the drive, have the user make a
backup copy of all the information on the drive if
possible.

Never remove the drive while the system is
operating or is in suspend mode.

For access, remove this FRU:
v “1010 Battery pack” on page 58

1

Note: The hard disk is attached to the cover.

Step Screw (quantity)

1 Coin screw (1) or security screw (1)

Note: Use a 2.5-mm Allen wrench to remove the security screw.

(continued)

ThinkPad T20, T21, T22 and T23 series 61

Removing and replacing a FRU

When removing the hard-disk drive, open the LCD a little
as shown in the figure.

2

3

4

3

When installing: Make sure that the HDD connector is

firmly connected.

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

Removing and replacing a FRU

1040 DIMM

For access, remove this FRU:
v “1010 Battery pack” on page 58

Note: Loosen the screw 1, but do not remove it.

1

2

3

When installing: With the notched end of the DIMM

toward the socket, insert the DIMM into
the socket, and then press it firmly. Pivot
the DIMM until it snaps into place. Make
sure that the card is firmly fixed in the
slot and does not move easily.

ThinkPad T20, T21, T22 and T23 series 63

4

3

Removing and replacing a FRU

1050 Mini PCI adapter

For access, remove this FRU:
v “1010 Battery pack” on page 58

For T20, T21 and T22 series

Note: Loosen the screw 1, but do not remove it.

1

2

(continued)

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

Removing and replacing a FRU

Note: The following illustration shows the combo card.

Connector (A) is for the LAN feature and (B) is for
the modem feature. Disconnect either (A) or (B) in
step 6. This slot also supports a Mini PCI modem
card or Mini PCI network card.

3

4

(B)

(A)

4

5

(continued)

(B)

(A)

6

ThinkPad T20, T21, T22 and T23 series 65

Removing and replacing a FRU

When installing: Make sure not to pinch the connector

cable when re-installing the Mini PCI
adapter.

For T23 series

Note: Loosen the screw 1, but do not remove it.

1

2

(continued)

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

Removing and replacing a FRU

In step 3a and 3b, pull the tab of the each antenna
cables to unplug the cables.

3a

3b

4

4

When installing: Plug the gray antenna cable 3a into

jack J1 (MAIN), and the black antenna
cable 3b into jack J2 (AUX).

5

6

When installing: With the notched end of the card toward

the socket, insert the card into the
socket, and then press it firmly. Pivot the
card until it snaps into place. Make sure
that the card is firmly fixed in the slot
and does not move easily.

ThinkPad T20, T21, T22 and T23 series 67

Removing and replacing a FRU

1060 Ethernet daughter card

Note

This section is only for the following models;
MT2647-2Kx, 5Kx, 5Lx, 6Kx, 9Kx, 9Lx. Other
models do not have the Ethernet daughter card
(EDC).

For access, remove this FRU:
v “1010 Battery pack” on page 58

Note: Loosen the screw 1, but do not remove it.

1

2

(continued)

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

Removing and replacing a FRU

3

Step Screw (quantity) Torque

3 M2.5 × 11.5 mm, nylon-coated (2) 39.2 Ncm

3

(4 kgfcm)

(continued)

ThinkPad T20, T21, T22 and T23 series 69

Removing and replacing a FRU

4

5

6

When installing: Make sure that both of the connectors

4 and 6 are firmly attached.

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

Removing and replacing a FRU

1070 Ultrabay 2000 device

Any of several devices can be inserted into the Ultrabay

2000. The procedure for installing and removing is the

same for every device.
Note: When you release the switch in step 1 the lever

pops out. Pull the lever a little in step 2 to release
the device from the bay.

1

2

3

ThinkPad T20, T21, T22 and T23 series 71

Removing and replacing a FRU

1080 Keyboard

For access, remove these FRUs, in order:

v “1010 Battery pack” on page 58
v “1020 Backup battery” on page 59
v “1030 Hard-disk drive” on page 61
v “1070 Ultrabay 2000 device” on page 71

For T20, T21 and T22 series

1

Step Screw (quantity) Torque

1 M2.5 × 14 mm, nylon-coated (2) 39.2 Ncm

Note: T20, T21 and T22 series do not have the removal

procedures 2 to 4. After step 1, go to step
5.

(continued)

(4 kgfcm)

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

Removing and replacing a FRU

For T23 series

Note: Loosen the screw 2, but do not remove it.

1

2

3

Step Screw (quantity) Torque

1 M2.5 × 14 mm, nylon-coated (2) 39.2 Ncm

(4 kgfcm)

4

Step Screw (quantity) Torque

4 M2.5 × 11.5 mm, nylon-coated (1) 39.2 Ncm

(4 kgfcm)

(continued)

ThinkPad T20, T21, T22 and T23 series 73

Removing and replacing a FRU

Note: Step 5 to 10 are common for all models.

6

5

5

(continued)

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

Removing and replacing a FRU

8

9

7

9

8

7

(continued)

10

9

ThinkPad T20, T21, T22 and T23 series 75

Removing and replacing a FRU

Note: Before installing a new keyboard, attach the

easy-button cover as follows:

4

3

2

1

1

(continued)

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

Removing and replacing a FRU

When installing the keyboard, do as follows:

1. Install the new keyboard, following the directions in the
figure. Make sure that the keyboard edges, shown in
the figure as (A), (B), and (C), are under the frame.

(A)

(continued)

(B)

(C)

ThinkPad T20, T21, T22 and T23 series 77

Removing and replacing a FRU

2. Insert your fingers into the PC Card slot on the left of
the computer and the Ultrabay 2000 slot on the right of
the computer as shown in 1 . Then, with your fingers
in those slots as in 2, latch the keyboard in place by
using your thumbs to press firmly on the shift keys.
Press the Y key to connect the keyboard to the
connector on the underside of the key 3.

3

1

1

2

(continued)

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

Removing and replacing a FRU

3. To make sure that the front side of the keyboard is
housed firmly, gently press the shift keys with your
thumbs and try to slide the keyboard towards you. Do
not push parts (A) and (B) on the keyboard strongly; to
do so might cause distortion of the Ultrabay 2000 slot
and the PC Card slot.

(A)

(B)

4. Replace the screws, using the new screws provided
with the keyboard. Then press the Y key again, hard,

to make sure that the keyboard is firmly connected.

ThinkPad T20, T21, T22 and T23 series 79

Removing and replacing a FRU

1090 Keyboard CRU insulator

For access, remove these FRUs, in order:

v “1010 Battery pack” on page 58
v “1020 Backup battery” on page 59
v “1030 Hard-disk drive” on page 61
v “1070 Ultrabay 2000 device” on page 71
v “1080 Keyboard” on page 72

Note: The shape of the keyboard CRU insulator vary from

model to model. In some models, the shape might
be slightly different from the insulator in this figure.

1

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

Removing and replacing a FRU

1100 Hinge cover

For access, remove these FRUs, in order:

v “1010 Battery pack” on page 58
v “1020 Backup battery” on page 59
v “1030 Hard-disk drive” on page 61
v “1070 Ultrabay 2000 device” on page 71
v “1080 Keyboard” on page 72
v “1090 Keyboard CRU insulator” on page 80

Note: Step 1 is common for all models.

1

Step Screw (quantity) Torque

1 M2.5 × 14 mm, nylon-coated (3) 39.2 Ncm

(4 kgfcm)

(continued)

ThinkPad T20, T21, T22 and T23 series 81

For T20 and T21 series

a a

Removing and replacing a FRU

4

2

3

Step Screw (quantity) Torque

2 M2.5 × 4.8 mm, nylon-coated (1) 39.2 Ncm

(4 kgfcm)

When installing:

1. Install the hinge cover according to the step 3, 4
and then tighten the screw 2. In step 3, take care
not to damage the lens.

2. Make sure that both latches a are firmly attached
and snap into place.

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

Removing and replacing a FRU

For T22 series

2

3

Step Screw (quantity) Torque

2 M2.5 × 14 mm, nylon-coated (1) 39.2 Ncm

(continued)

(4 kgfcm)

ThinkPad T20, T21, T22 and T23 series 83

Removing and replacing a FRU

aa

6

4

5

Step Screw (quantity) Torque

4 M2.5 × 4.8 mm, nylon-coated (1) 39.2 Ncm

(4 kgfcm)

When installing:

1. Install the hinge cover according to the step 5, 6
and then tighten the screw 4. In step 5, take care
not to damage the lens.

2. Make sure that both latches a are firmly attached
and snap into place.

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

For T23 series

Removing and replacing a FRU

aa

4

2

3

Step Screw (quantity) Torque

2 M2.5 × 4.8 mm, nylon-coated (1) 39.2 Ncm

(4 kgfcm)

When installing:

1. Install the hinge cover according to the step 3, 4
and then tighten the screw 2. In step 3, take care
not to damage the lens.

2. Make sure that both latches a are firmly attached
and snap into place.

ThinkPad T20, T21, T22 and T23 series 85

Removing and replacing a FRU

1110 Keyboard bezel

For access, remove these FRUs, in order:

v “1010 Battery pack” on page 58
v “1020 Backup battery” on page 59
v “1030 Hard-disk drive” on page 61
v “1070 Ultrabay 2000 device” on page 71
v “1080 Keyboard” on page 72
v “1090 Keyboard CRU insulator” on page 80
v “1100 Hinge cover” on page 81

For T20, T21 and T22 series

1

Step Screw (quantity) Torque

1 M2.5 × 3.5 mm, nylon-coated (3) 39.2 Ncm

(4 kgfcm)

(continued)

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

Removing and replacing a FRU

2

4

3

Step Screw (quantity) Torque

2 M2.5 × 14 mm, nylon-coated (1) 39.2 Ncm

3 M2.5 × 4.8 mm, nylon-coated (1) 39.2 Ncm

(4 kgfcm)

(4 kgfcm)

(continued)

ThinkPad T20, T21, T22 and T23 series 87

Removing and replacing a FRU

For T23 series

Note: Loosen the screw 1, but do not remove it.

1

2

3

Step Screw (quantity) Torque

3 M2.5 × 11.5 mm, nylon-coated (1) 39.2 Ncm

(4 kgfcm)

(continued)

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

Removing and replacing a FRU

4

Step Screw (quantity) Torque

4 M2.5 × 3.5 mm, nylon-coated (3) 39.2 Ncm

(4 kgfcm)

(continued)

ThinkPad T20, T21, T22 and T23 series 89

Removing and replacing a FRU

5

6

7

Step Screw (quantity) Torque

5 M2.5 × 14 mm, nylon-coated (1) 39.2 Ncm

6 M2.5 × 4.8 mm, nylon-coated (1) 39.2 Ncm

(4 kgfcm)

(4 kgfcm)

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

Removing and replacing a FRU

When installing, do as follows:

v Make sure that the a-part is firmly attached as shown

in the figure.

v Make sure that all of the latches of the keyboard bezel

bare firmly attached.

a

b

b

b

b

ThinkPad T20, T21, T22 and T23 series 91

Removing and replacing a FRU

1120 Fan assembly

For T20, T21, T22 series

For access, remove these FRUs, in order:

v “1010 Battery pack” on page 58
v “1020 Backup battery” on page 59
v “1030 Hard-disk drive” on page 61
v “1070 Ultrabay 2000 device” on page 71
v “1080 Keyboard” on page 72
v “1090 Keyboard CRU insulator” on page 80

1

2

1

a

b

Notes:

1. a-part is for T21, T22 series only. Other models do
not have this bracket.

2. b -part is for T21 series and MT2647-3Cx, -3Ex,

-7Cx, -7Ex (T22 series) only. Other models do not have
this bracket.

Step Screw (quantity) Torque

1 M2.0 × 13.5 mm, nylon-coated (4) 24.5 Ncm

(2.5 kgfcm)

(continued)

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

Removing and replacing a FRU

When installing the fan assembly:

For T20

Remove the protective sheet from the thermal rubber
on the fan assembly.

For T21, T22

Apply the thermal grease (05K5751) on the a-part of
the fan as shown in the following figure.

a

ThinkPad T20, T21, T22 and T23 series 93

Removing and replacing a FRU

For T23 series

For access, remove these FRUs, in order:

v “1010 Battery pack” on page 58
v “1020 Backup battery” on page 59
v “1030 Hard-disk drive” on page 61
v “1070 Ultrabay 2000 device” on page 71
v “1080 Keyboard” on page 72
v “1090 Keyboard CRU insulator” on page 80
v “1100 Hinge cover” on page 81
v “1110 Keyboard bezel” on page 86

1

2

3

Step Screw (quantity) Torque

1 M2.0× 13.5 mm, nylon-coated (1) 24.5 Ncm

2 M2.5 × 14 mm, nylon-coated (1) 39.2 Ncm

(2.5 kgfcm)

(4 kgfcm)

(continued)

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

Removing and replacing a FRU

4

6

5

Step Screw (quantity) Torque

4 M2.0 × 13.5 mm, nylon-coated (3) 24.5 Ncm

(2.5 kgfcm)

(continued)

ThinkPad T20, T21, T22 and T23 series 95

Removing and replacing a FRU

When installing: Apply the thermal grease (05K5751) on

the a-part of the fan as shown in the
following figure.

a

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