Lenovo N23 Owner's manual

Lenovo N23
Hardware
Maintenance
Manual

Notes:
• Beforeusingthisinformationandtheproductitsupports,besuretoreadthegeneralinformationunder
“Notices”onpage64.
First Edition (June 2016)
© Copyright Lenovo 2016. 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.
© 2016 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 .........................21
Related service information ...................... 23
Restoring the factory contents by using
OneKey Recovery ........................................ 23
Restore of factory default .................................23
Passwords.................................................... 24
Power-on password.......................................... 24
Hard-disk password.......................................... 24
Supervisor 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.............................26
Lenovo N23 ................................................. 27
Specications ............................................... 27
Status indicators........................................... 29
Fn key combinations..................................... 30
FRU replacement notices............................. 31
Screw notices ..................................................31
Removing and replacing an FRU ................. 32
1010 Base cover...............................................33
1020 Battery pack.............................................35
1030 PCI Express Mini Card for wireless
LAN ..................................................................36
1040 LCD unit...................................................38
1050 System board ..........................................40
1060 Speakers .................................................42
1070 Touch pad module and IO board .............43
1080 LCD module.............................................45
1090 LCD cable, LCD bracket and hinges .......47
1100 camera .....................................................49
1110 Antenna assembly and LCD cover...........50
Locations ...................................................... 51
Front view and right-side view ..........................51
Bottom and Left-side view ...............................52
Parts list........................................................ 53
Overall ..............................................................54
LCD FRUs ........................................................57
Miscellaneous parts.......................................... 59
Screw................................................................59
AC adapters......................................................60
Power cords......................................................61
Notices......................................................... 64
Trademarks .................................................. 65

iv
About this manual
This manual contains service and reference information for the following
Lenovo product:
Lenovo N23
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 N23 computer:
• “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

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Lenovo N23 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.

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About this manual
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.

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Lenovo N23 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.

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About this manual
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 N23 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.

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About this manual
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 N23 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.

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About this manual
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 N23 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.

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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 N23 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.

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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.

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Lenovo N23 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.

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About this manual
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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!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.

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Lenovo N23 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.