Lenovo N24 Owner's manual

Lenovo N24
Hardware
Maintenance
Manual

Note: Before using this information and the product it supports, be sure to read the general information
under “Notices” on page 63.
First Edition (April. 2017)
© Copyright Lenovo 2017. All rights reserved.
LIMITED AND RESTRICTED RIGHTS NOTICE: If data or software is delivered pursuant a General
Services Administration “GSA” contract, use, reproduction, or disclosure is subject to restrictions set
forth in Contract No. GS-35F-05925.
© 2017 Lenovo

iii
Contents
About this manual ....................................... iv
Safety information........................................ 1
General safety ................................................ 2
Electrical safety .............................................. 3
Safety inspection guide .................................. 5
Handling devices that are sensitive to
electrostatic discharge.................................... 6
Grounding requirements................................. 6
Safety notices: multilingual translations.......... 7
Laser compliance statement......................... 14
Important service information................... 16
Strategy for replacing FRUs ......................... 16
Strategy for replacing a hard disk drive ............17
Important notice for replacing a
system board ...................................................17
Important information about replacing
RoHS compliant FRUs ................................. 18
General checkout ...................................... 19
What to do rst ............................................. 20
Power system checkout................................ 21
Checking the AC adapter .................................21
Checking operational charging .........................22
Checking the battery pack ................................22
Related service information ...................... 23
Restoring the factory contents by using
recovery system ........................................... 23
Restore of factory default .................................23
Passwords.................................................... 24
Power-on password.......................................... 24
Hard-disk password.......................................... 24
Administrator password ....................................24
Power management ..................................... 25
Screen blank state............................................25
Putting the computer to sleep or
shutting it down.................................................25
Putting your computer to sleep......................... 25
Shutting down the computer.............................25
Lenovo N24 ................................................. 26
Specications ............................................... 26
Status indicators........................................... 28
Fn key combinations/Hotkeys....................... 29
FRU replacement notices............................. 30
Screw notices ..................................................30
Removing and replacing an FRU ................. 31
1010 Base cover...............................................32
1020 Battery pack.............................................34
1030 PCI Express Mini Card for wireless LAN .....35
1040 IO Board ..................................................37
1050 Touchpad button board............................38
1060 Speaker ...................................................39
1070 Upper case ..............................................40
1080
System board............................................ 42
1090 LCD cover................................................45
1100 Pen holder................................................46
1110 Hinges ......................................................47
1120 Camera board, sensor board and
LCD cable.........................................................49
Locations ...................................................... 52
Front and right-side view ..................................52
Bottom and left-side view ................................53
Parts list........................................................ 54
Overall ..............................................................55
LCD FRUs ........................................................58
Miscellaneous parts.......................................... 59
AC adapters......................................................59
Screws..............................................................59
Power cords......................................................60
Notices......................................................... 63
Trademarks .................................................. 64

iv
About this manual
This manual contains service and reference information for the following
Lenovo product:
Lenovo N24
Use this manual to troubleshoot problems.
The manual is divided into the following sections:
• The common sections provide general information, guidelines, and safety
information required for servicing computers.
• The product-specic section includes service, reference, and product-specic
parts information.
Important:
This manual is intended only for trained servicers who are familiar with Lenovo
products. Use this manual to troubleshoot problems effectively.
Before servicing a Lenovo product, make sure to read all the information under
“Safety information” on page 1 and “Important service information” on page 16.

1
Safety information
Safety information
This chapter presents the following safety information that you need to get
familiar with before you service a Lenovo N24:
• “General safety” on page 2
• “Electrical safety” on page 3
• “Safety inspection guide” on page 5
• “Handling devices that are sensitive to electrostatic discharge” on page 6
• “Grounding requirements” on page 6
• “Safety notices: multilingual translations” on page 7
• “Laser compliance statement” on page 14

2
Lenovo N24 Hardware Maintenance Manual
General safety
Follow these rules below to ensure general safety:
• Observe a good housekeeping in the area where the machines are put
during and after the maintenance.
• When lifting any heavy object:
1. Make sure that 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 it.
4. Lift it by standing or pushing up with your leg muscles; this action could
avoid the strain from the muscles in your back. Do not attempt to lift any
object that weighs more than 16 kg (35 lb) or that you think is too heavy
for you.
• Do not perform any action that causes hazards to the customer, or that
makes the machine unsafe.
• Before you start the machine, make sure that other service representatives
and the customer are not in a hazardous position.
• Please remove covers and other parts in a safe place, away from all
personnel, while you are servicing the machine.
• Keep your toolcase away from walk areas so that other people will not trip
over it.
• Do not wear loose clothing that can be trapped in the moving parts of the
machine. Make sure that your sleeves are fastened or rolled up above your
elbows. If your hair is long, fasten it.
• Insert the ends of your necktie or scarf inside clothing or fasten it with the
nonconductive clip, about 8 centimeters (3 inches) from the end.
• Do not wear jewelry, chains, metal-frame eyeglasses, or metal fasteners for
your clothing.
Attention: Metal objects are good electrical conductors.
• Wear safety glasses when you are hammering, drilling, soldering, cutting
wire, attaching springs, using solvents, or working in any other conditions
that may be hazardous to your eyes.
• After service, reinstall all safety shields, guards, labels, and ground wires.
Replace any safety device that is worn or defective.
• Reinstall all covers correctly before returning the machine to the customer.
• Fan louvers on the machine help to prevent the overheating of internal
components. Do not obstruct fan louvers or cover them with labels or
stickers.

3
Safety information
Electrical safety
Observe the following rules when working on electrical equipments.
Important:
Use only approved tools and test equipments. Some hand tools have handles
covered with a soft material that does not insulate you when working with live
electrical currents.
Many customers have rubber floor mats near their machines that contain small
conductive bers to decrease electrostatic discharges. Do not use such kind of mat
to protect yourself from electrical shock.
• 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.
• Do not work alone under hazardous conditions or near the equipment that
has hazardous voltages.
• Disconnect all power before:
– Performing a mechanical inspection
– Working near power supplies
– Removing or installing main units
• 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.
• 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 oor strips and machine frames.
Observe the special safety precautions when you work with very high voltages;
instructions for these precautions are in the safety sections of maintenance
information. Be extremely careful when you measure the high voltages.
• Regularly inspect and maintain your electrical hand tools for safe operational
condition.
• Do not use worn or broken tools and testers.
• Never assume that power has been disconnected from a circuit. First, check
it to make sure that it has been powered off.

4
Lenovo N24 Hardware Maintenance Manual
• Always look carefully for possible hazards in your work area. Examples of
these hazards are moist oors, nongrounded power extension cables, power
surges, and missing safety grounds.
• 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.
• 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.)
• If an electrical accident occurs:
– Caution: do not become a victim yourself.
– Switch off the power.
– Send the victim to get medical aid.

5
Safety information
Safety inspection guide
The purpose of this inspection guide is to assist you in identifying potential
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 according to the attachment of non-Lenovo 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 rst correcting
the problem.
Consider these conditions and the safety hazards they present:
• Electrical hazards, especially primary power (primary voltage on the frame
can cause serious or fatal electrical shock)
• Explosive hazards, such as a damaged CRT face or a bulging capacitor
• Mechanical hazards, such as loose or missing hardware
To determine whether there are any potential 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. Turn 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 the frame ground.
b. The power cord should be the type specied in the parts list.
c. Insulation must not be frayed or worn.
4. Check for cracked or bulging batteries.
5. Remove the cover.
6. Check for any obvious non-Lenovo alterations. Use good judgment as to the
safety of any non-Lenovo alterations.
7. 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.
8. Check for worn, frayed, or pinched cables.
9. Check that the power-supply cover fasteners (screws or rivets) have not
been removed or tampered with.

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Lenovo N24 Hardware Maintenance Manual
Handling devices that are sensitive to electrostatic discharge
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 certied (ISO
9000) as fully effective.
When handling ESD-sensitive parts:
• Keep the parts in protective packages until they are inserted into the product.
• Avoid contact with other people.
• Wear a grounded wrist strap against your skin to eliminate static on your
body.
• Prevent the part from touching your clothing. Most clothing is insulative and
retains a charge even when you are wearing a wrist strap.
• 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.
• Select a grounding system, such as those listed below, to provide protection
that meets the specic service requirement.
Note:
The use of a grounding system to guard against ESD damage is desirable but not
necessary.
– Attach the ESD ground clip to any frame ground, ground braid, or green-
wire ground.
– When working on a double-insulated or battery-operated system, use an
ESD common ground or reference point. 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 veried by a
certied electrician.

7
Safety information
Safety notices: multilingual translations
The safety notices in this section are provided in English, French, German,
Hebrew, Italian, Japanese, and Spanish.
Safety notice 1
Before the computer is powered on after FRU replacement, make sure all screws,
springs, and other small parts are in place and are not left loose inside the
computer. Verify this by shaking the computer and listening for rattling sounds.
Metallic parts or metal akes can cause electrical shorts.
Avant de remettre l’ordinateur sous tension après remplacement d’une unité en
clientèle, vériez que tous les ressorts, vis et autres pièces sont bien en place et
bien xées. 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.
Vericare ciò scuotendo l’elaboratore e prestando attenzione ad eventuali rumori;
eventuali parti o pezzetti metallici possono provocare cortocircuiti pericolosi.
Antes de encender el sistema despues de sustituir una FRU, compruebe que
todos los tornillos, muelles y demás piezas pequeñas se encuentran en su sitio
y no se encuentran sueltas dentro del sistema. Compruébelo agitando el sistema
y escuchando los posibles ruidos que provocarían. Las piezas metálicas pueden
causar cortocircuitos eléctricos.

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Lenovo N24 Hardware Maintenance Manual
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 nicht zerlegt,
wiederaufgeladen, kurzgeschlossen, oder Feuer oder Wasser ausgesetzt werden.
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.
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 utilización de una batería no apropiada puede
provocar la ignición o explosión de la misma.

9
Safety information
Safety notice 3
DANGER
The battery pack contains small amounts of nickel. Do not disassemble it, throw
it into re 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 batería no apropiada puede
provocar la ignición o explosión de la misma.

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Lenovo N24 Hardware Maintenance Manual
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.
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 o l’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.

11
Safety information
Safety notice 5
If the LCD breaks and the uid from inside the LCD gets into your eyes or on your
hands, immediately wash the affected areas with water at least for 15 minutes.
Seek medical care if any symptoms caused by the uid are present after washing.
Si le panneau d’afchage à cristaux liquides se brise et que vous recevez dans les
yeux ou sur les mains une partie du uide, rincez-les abondamment pendant au
moins quinze minutes. Consultez un médecin si des symptômes persistent après le
lavage.
Die Leuchtstoffröhre im LCD-Bildschirm enthält Quecksilber. Bei der Entsorgung
die örtlichen Bestimmungen für Sondermüll beachten. Der LCD-Bildschirm
besteht aus Glas und kann zerbrechen, wenn er unsachgemäß behandelt wird
oder der Computer auf den Boden fällt. Wenn der Bildschirm beschädigt ist und
die darin befindliche Flüssigkeit in Kontakt mit Haut und Augen gerät, sollten
die betroffenen Stellen mindestens 15 Minuten mit Wasser abgespült und bei
Beschwerden anschließend ein Arzt aufgesucht werden.
Nel caso che caso l’LCD si dovesse rompere ed il liquido in esso contenuto
entrasse in contatto con gli occhi o le mani, lavare immediatamente le parti
interessate con acqua corrente per almeno 15 minuti; poi consultare un medico se i
sintomi dovessero permanere.
Si la LCD se rompe y el uido 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 algún síntoma del uido
despues de lavarse.

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Lenovo N24 Hardware Maintenance Manual
Safety notice 6
DANGER
To avoid shock, do not remove the plastic cover that protects the lower part of the
inverter card.
An d’éviter tout risque de choc électrique, ne retirez pas le cache en plastique
protégeant la partie inférieure de la carte d’alimentation.
Aus Sicherheitsgründen die Kunststoffabdeckung, die den unteren Teil der
Spannungswandlerplatine umgibt, nicht entfernen.
Per evitare scosse elettriche, non rimuovere la copertura in plastica che avvolge la
parte inferiore della scheda invertitore.
Para evitar descargas, no quite la cubierta de plástico que rodea la parte baja de la
tarjeta invertida.
Safety 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 sufsamment 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 suciente como para quemar
material combustible o provocar quemaduras en el personal.

13
Safety information
Safety notice 8
DANGER
Before removing any FRU, turn 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.

14
Lenovo N24 Hardware Maintenance Manual
Laser compliance statement
Some models of Lenovo computer are equipped from the factory with an
optical storage device such as a CD-ROM drive or a DVD-ROM drive. Such
devices are also sold separately as options. If one of these drives is installed,
it is certied 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.
If a CD-ROM drive, a DVD-ROM drive, or another laser device is installed, note
the following:
CAUTION
Use of controls or adjustments or performance of procedures other than those
specied herein might result in hazardous radiation exposure.
O uso de controles, ajustes ou desempenho de procedimentos diferentes daqueles
aqui especicados 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
specicate possono provocare l’esposizione a.
El uso de controles o ajustes o la ejecución de procedimientos distintos de los aquí
especicados puede provocar la exposición a radiaciones peligrosas.
Opening the CD-ROM drive, the DVD-ROM drive, or any other optical storage
device could result in exposure to hazardous laser radiation. There are no
serviceable parts inside those drives. Do not open.

15
Safety information
A CD-ROM drive, a DVD-ROM drive, or any other storage device installed may
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 xo 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 ! Ne nézzen bele se szabad szemmel, se optikai
eszközökkel. Kerülje a sugárnyalábbal való érintkezést!
Aprendo l’unità vengono emesse radiazioni laser. Non fissare il fascio, non
guardarlo direttamente con strumenti ottici e evitare l’esposizione diretta al fascio.
Radiación láser al abrir. No mire jamente ni examine con instrumental óptico el
haz de luz. Evite la exposición directa al haz.

16
Lenovo N24 Hardware Maintenance Manual
Important service information
This chapter presents the following important service information:
• “Strategy for replacing FRUs” on page 16
– “Strategy for replacing a hard disk drive” on page 17
– “Important notice for replacing a system board” on page 17
• “Important information about replacing RoHS compliant FRUs” on page 18
Important:
BIOS and device driver xes are customer-installable. The BIOS and device drivers
are posted on the customer support site:
http://support.lenovo.com.
Strategy for replacing FRUs
Before replacing parts:
Make sure that all software xes, drivers, and BIOS downloads are installed
before replacing any FRUs listed in this manual.
After a system board is replaced, ensure that the latest BIOS is loaded to the
system board before completing the service action.
To download software xes, drivers, and BIOS, follow the steps below:
1. Go to http://support.lenovo.com.
2. Enter the serial number or select a product or use Lenovo smart
downloading.
3. Select the BIOS/Driver/Applications and download.
4. Follow the directions on the screen and install the necessary software.