YOGA TABLET 2

Hardware Maintenance Manual

YOGA Tablet 2-851F

 Note:
Before using this information and the product it supports, be sure to read the general information
under “Notices” on page 83.

First Edition (Sep 2014)

© Copyright Lenovo 2014. All rights reserved.
LENOVO products, data, computer software, and services have been developed exclusively at private
expense and are sold to governmental entities as commercial items as defined by 48 C.F.R. 2.101 with
limited and restricted rights to use, reproduction and disclosure.
LIMITED AND RESTRICTED RIGHTS NOTICE: If products, data, computer software, or services are
delivered pursuant to a General Services Administration “GSA” contract, use, reproduction, or disclo-
sure is subject to restrictions set forth in Contract No. GS-35F-05925.
© 2014 Lenovo
 Contents
About this manual........................................iv Locations ............................................................. 76
Front view..................................................... 76
Safety information.........................................1 Rear view ...................................................... 77
General safety ...................................................... 2 Parts list............................................................... 78
Electrical safety .................................................... 3 Overall ........................................................... 78
Safety inspection guide ...................................... 5 Screws............................................................ 82
Handling devices that are sensitive to electro-
static discharge .................................................... 6 Notices .........................................................83
Grounding requirements ................................... 6 Trademarks......................................................... 84
Safety notices: multilingual translations.......... 7
Laser compliance statement............................. 14

Important service information ...................16

Strategy for replacing FRUs............................. 16
Important notice for replacing a system
board ............................................................. 17
Important information about replacing RoHS
compliant FRUs ................................................. 18

General checkout ........................................19

What to do first .................................................. 20
Power system checkout .................................... 21
Checking the Computer AC Charger....... 21
Checking the internal battery status......... 22

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

Security ............................................................... 23
Power management .......................................... 23
Activating/Deactivating the Display ........ 23

Lenovo 851 ..................................................24

Specifications ..................................................... 24
FRU replacement notices.................................. 26
Screw notices................................................ 26
Removing and replacing an FRU.................... 27
1010 Rear cover............................................ 28
1020 Right speaker ...................................... 31
1030 Sub board............................................. 34
1040 LCD FPC.............................................. 38
1050 Main FPC ............................................. 41
1060 Hall sensor FPC .................................. 44
1070 Main board .......................................... 47
1080 Left speaker ......................................... 55
1090 Rear camera......................................... 59
1100 USB and volume key FPC ................. 61
1110 Volume key ......................................... 63
1120 WIFI2 antenna..................................... 64
1130 GPS/WIFI1 antenna............................ 66
1140 Windows key ...................................... 68
1150 Battery pack......................................... 69
1160 Power key ............................................ 74

iii
 About this manual
This manual contains service and reference information for the following
Lenovo product of the specified versions:
• Lenovo 851 (WiFi version)
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-specific section includes service, reference, and product-specific
parts information.

Note:
The information provided in this manual is applicable to both product
versions mentioned above, unless otherwise specified.

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.

iv
 Safety information

Safety information
This chapter presents the following safety information that you need to get
familiar with before you service a Lenovo 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 851 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.
• Place removed covers and other parts in a safe place, keeping them away
from all personnel, while you are servicing the machine.
• Keep your toolcase away from walk areas so that other people will not trip it
over.
• 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.

2
 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 fibers 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 for disconnecting the
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 floor 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 851 Hardware Maintenance Manual

• 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.
• 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.

4
 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 first 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 specified 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 851 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 certified
(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 specific service requirement.

Notes:
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 verified by a
certified electrician.

6
 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 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 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 851 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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 Safety information

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 batería no
apropiada puede provocar la ignición o explosión de la misma.

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 Lenovo 851 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 information

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 at least for
15 minutes. Seek medical care if any symptoms caused by 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 après le lavage.
Die Leuchtstoffröhre im LCD-Bildschirm enthält Quecksilber. Bei der
Entsorgung die örtlichen Bestimmungen für Sondermüll beachten. Der
LCD-Bildschirm besteht aus Glas und kann zerbrechen, wenn er
unsachgemäß behandelt wird oder der Computer auf den Boden fällt. Wenn
der Bildschirm beschädigt ist und die darin befindliche Flüssigkeit in
Kontakt mit Haut und Augen gerät, sollten die betroffenen Stellen
mindestens 15 Minuten mit Wasser abgespült und bei Beschwerden
anschließend ein Arzt aufgesucht werden.

Nel caso che caso l’LCD si dovesse rompere ed il liquido in esso contenuto
entrasse in contatto con gli occhi o le mani, lavare immediatamente le parti
interessate con acqua corrente per almeno 15 minuti; poi consultare un
medico se i sintomi dovessero permanere.

Si la LCD se rompe y el fluido de su interior entra en contacto con sus ojos o

sus manos, lave inmediatamente las áreas afectadas con agua durante
15 minutos como mínimo. Obtenga atención medica si se presenta algún

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Safety notice 6
DANGER
To avoid shock, do not remove the plastic cover that protects the lower part
of the inverter card.
Afin d’éviter tout risque de choc électrique, ne retirez pas le cache en
plastique protégeant la partie inférieure de la carte d’alimentation.
Aus Sicherheitsgründen die Kunststoffabdeckung, die den unteren Teil der
Spannungswandlerplatine umgibt, nicht entfernen.

Per evitare scosse elettriche, non rimuovere la copertura in plastica che

avvolge la parte inferiore della scheda invertitore.

Para evitar descargas, no quite la cubierta de plástico que rodea la parte baja
de la tarjeta invertida.

Safety 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.

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 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.

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 Lenovo 851 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 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.

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 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, 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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 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 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 fijamente ni examine con instrumental

óptico el haz de luz. Evite la exposición directa al haz.

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 Lenovo 851 Hardware Maintenance Manual

Important service information

This chapter presents the following important service information:
• “Strategy for replacing FRUs” on page 16
— “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 fixes are customer-installable. The BIOS and device
drivers are posted on the customer support site:
http://consumersupport.lenovo.com/.

Strategy for replacing FRUs

Before replacing parts:

Make sure that all software fixes, 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 fixes, drivers, and BIOS, follow the steps below:
1. Go to http://consumersupport.lenovo.com/.
2. Enter a 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.

Use the following strategy to prevent unnecessary expense for replacing and
servicing FRUs:
• If you are instructed to replace an FRU, but the replacement does not solve
the problem, reinstall the original FRU before you continue.
• Some computers have both a processor board and a system board. If you are
instructed to replace either of them, and replacing one of them does not solve
the problem, reinstall that board, and then replace the other one.
• If an adapter or a device consists of more than one FRU, any of the FRUs may
be the cause of the error. Before replacing the adapter or device, remove the
FRUs one by one to see if the symptoms change. Replace only the FRU that
changed the symptoms.
Attention: The setup configuration on the computer you are servicing may have
been customized. Running Automatic Configuration may alter the settings. Note
the current configuration settings (using the View Configuration option); then,
when service has been completed, verify that those settings remain in effect.

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 Important service information

Important notice for replacing a system board

Some components mounted on a system board are very sensitive. Improper
handling can cause damage to those components, and may cause a system
malfunction.
Attention: When handling a system board:
• Do not drop the system board or apply any excessive force to it.
• Avoid rough handling of any kind.
• Avoid bending the system board and hard pushing to prevent cracking at
each BGA (Ball Grid Array) chipset.

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 Lenovo 851 Hardware Maintenance Manual

Important information about replacing RoHS compliant FRUs

RoHS, The Restriction of Hazardous Substances in Electrical and

Electronic Equipment Directive (2002/95/EC) is a European Union legal
requirement affecting the global electronics industry. RoHS requirements
must be implemented on Lenovo products placed on the market after June
2006. Products on the market before June 2006 are not required to have
RoHS compliant parts. If the original FRU parts are non-compliant,
replacement parts can also be non-compliant. In all cases if the original
FRU parts are RoHS compliant, the replacement part must also be RoHS
compliant.

Note: RoHS and non-RoHS FRU part numbers with the same fit and function are
identified with unique FRU part numbers.

Lenovo plans to transit to RoHS compliance well before the implementation date
and expects its suppliers to be ready to support Lenovo’s requirements and
schedule in the EU. Products sold in 2005 and 2006 will contain some RoHS
compliant FRUs. The following statement pertains to these products and any
product Lenovo produces containing RoHS compliant FRUs.

RoHS compliant FRUs have unique FRU part numbers. Before or after the RoHS
implementation date, failed RoHS compliant parts must always be replaced with
RoHS compliant ones, so only the FRUs identified as compliant in the system
HMM or direct substitutions for those FRUs may be used.

Products marketed before June 2006 Products marketed after June 2006
Current or Replacement Current or Replacement
original part FRU original part FRU
Non-RoHS Can be Non-RoHS
Non-RoHS Can be RoHS
Must be RoHS Must be RoHS
Non-RoHS Can sub to RoHS
RoHS Must be RoHS

Note: A direct substitution is a part with a different FRU part number that is
automatically shipped by the distribution center at the time of the order.

18
 General checkout

General checkout
This chapter presents the following information:
• “What to do first” on page 20
• “Power system checkout” on page 21

Before you go to the checkout, make sure to read the following important notes:

Important notes:
• Only certified trained personnel can service the computer.
• Before replacing any FRU, read the entire page on removing and
replacing FRUs.
• When you replace FRUs, use new nylon-coated screws.
• 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.
• Replace an FRU only with another FRU of the correct model. When
you replace an FRU, make sure that the machine model and the FRU part
number are correct by referring to the FRU parts list.
• An FRU should not be replaced just 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 an FRU
only when a problem recurs. If you suspect that an FRU is defective,
clear the error logs and run the test again. If the error does not recur, do
not replace the FRU.
• Be careful not to replace a nondefective FRU.

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 Lenovo 851 Hardware Maintenance Manual

What to do first

When you do return an 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. Procedure index and page number in which the failing FRU was detected
6. Failing FRU name and part number
7. Machine type, model number, and serial number
8. 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 is a list of 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 list:

The following are not covered under warranty:

• LCD panel cracked from the application of excessive force or from being
dropped
• Scratched (cosmetic) parts
• Distortion, deformation, or discoloration of the cosmetic parts
• Plastic parts, latches, pins, or connectors that have been cracked or broken by
excessive force
• Damage caused by liquid spilled into the system
• Damage caused by the improper insertion of a PC Card or the installation of
an incompatible card
• Improper disk insertion or use of an optical drive
• Diskette drive damage caused by pressure on the diskette drive cover,
foreign material in the drive, or the insertion of a diskette with multiple
labels
• Damaged or bent diskette eject button
• Fuses blown by attachment of a nonsupported device
• Forgotten computer password (making the computer unusable)
• Sticky keys caused by spilling a liquid onto the keyboard
• Use of an incorrect AC adapter on laptop products

The following symptoms might indicate damage caused by nonwarranted

activities:
• Missing parts might be a symptom of unauthorized service or modification.
• If the spindle of a hard disk drive becomes noisy, it may have been subjected
to excessive force, or dropped.

20
 General checkout

Power system checkout

To verify a symptom, follow the steps below:

1. Turn off the computer.
2. Remove the battery pack.
3. Connect the AC adapter.
4. Make sure that power is supplied when you turn on the computer.
5. Turn off the computer.
6. Disconnect the AC adapter and install the charged battery pack.
7. Make sure that the battery pack supplies power when you turn on the
computer.

If you suspect a power problem, see the appropriate one of the following power
supply checkouts:
• “Checking the Computer AC Charger” on page 21
• “Checking the internal battery status” on page 22

Checking the Computer AC Charger

When you use the computer AC Charger to charge the tablet but no power is
charged, see the instructions in this topic to check the computer AC Charger.
To check the computer AC Charger, do the following:
1. Disconnect the micro-USB cable from the tablet.
2. Measure the output voltage across the connector marked B of the micro-USB
cable. Refer to the following figure:

12 3 (5V) Pin Voltage (V dc)

1 Ground
2 0
3 +5

Note: The output voltage across pin 3 of the micro-B connector might be
different from the one you are servicing.
3. If the voltage is not correct, replace the micro-USB cable.
4. If the voltage is acceptable, replace the system board.

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 Lenovo 851 Hardware Maintenance Manual

Checking the internal battery status

To check the battery status of the tablet, do either of the following:
• Approximate information about the battery status
Get the approximate status of the battery at any time by checking the battery
status icon on the system bar in the upper-right corner of the screen. The
shorter the green bar is, the less the battery power remains.
• Accurate information about the battery status
To get the accurate information about the battery status of the tablet, do the
following:
1. Open the Android Settings screen.
To open the Android Settings screen, do either of the following:
– From the main Home screen, touch the Android Settings icon on
Lenovo Launch Zone. The Android Settings screen is displayed.
– Pull down the application icon from the action bar and then touch
Settings. The Android Settings screen is displayed.
2. Touch Battery in the Device section on the Android Settings screen.
3. The accurate percentage of the remaining battery power is shown on the
screen.

22
 Related service information

Related service information

This chapter presents the following information:
• “Security” on page 23
• “Power management” on page 23

Security

Security settings include: SCREEN SECURITY, SIM CARD LOCK (LTE version
only), PASSWORDS, DEVICE ADMINISTRATION and CREDENTIAL
STORAGE.

Power management

Note: Power management modes are not supported for APM operating system.

To reduce power consumption, the computer has three power management

modes: screen blank, sleep (standby), and hibernation.

Activating/Deactivating the Display

With the display deactivated, press the Power button on the computer to activate
the display. The computer display will then illuminate, indicating that it has
been activated.
If you do not need to use your computer temporarily, you can press the Power
button to deactivate the display. Your computer will then enter standby mode to
save power.

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 Lenovo 851 Hardware Maintenance Manual

Lenovo 851
This chapter presents the following product-specific service references and
product-specific parts information:
• “Specifications” on page 24
• “FRU replacement notices” on page 26
• “Removing and replacing an FRU” on page 27
• “Locations” on page 76
• “Parts list” on page 78

Specifications

The following table lists the specifications of the Lenovo 851 tablet.

Table 1. Specifications
Feature Description
Size & Weight
Size • 210mm x 148.9mm x (2.7 ~ 7.0)mm
Weight • < 400g

System
CPU • 1.86GHz, Quad Cores
Hardware Platform • Intel® Bay Trail-T Atom™ Processor Z3745
RAM • LP-DDR3 2GB (64bit)
Storage Capacity • 16GB / 32GB
LCD • 8.0”, 1,920 x 1,200 pixels
Integrated Camera • Rear camera, 8.0Mega pixels, Auto Focus
• Front camera, 1.6Mega pixels, HD Fixed Focus
Battery • Li-ion battery, 6,400mAh
Operating System
• Windows 8.1

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 Lenovo 851

Ports
• Micro-USB (USB 2.0)
• Audio Jack, 3.5mm
• Micro-SD card slot (support external Micro-SD
card up to 64GB)
Communication
• WiFi: 802.11a/b/g/n
• Bluetooth 4.0
• GPS
Others
• Speaker (Left and right)
• Microphone
• Gravity sensor
• E-compass
• Ambient light sensor
• Hall sensor
• Battery Manager
• LED indicator (on power button)
• Dolby audio system (DS1)
• Miracast
• Magnet
• WiFi Display

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 Lenovo 851 Hardware Maintenance Manual

FRU replacement notices

This section presents 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 Lenovo computers, this problem
is addressed with special nylon-coated screws that have the following
characteristics:
• They maintain tight connections.
• They do not easily come loose, even with shock or vibration.
• They are harder to tighten.
• Each one should be used only once.

Do the following when you service this machine:

• Keep the screw kit in your tool bag.
• Always use new screws.
• Use a torque screwdriver if you have one.

Tighten screws as follows:

• Plastic to plastic
Turn an additional 90° after the screw head touches the surface of the plastic
part:
more than 90°

(Cross-section)

• Logic card to plastic

Turn an additional 180° after the screw head touches the surface of the logic
card:
more than 180°

(Cross-section)

• Torque driver
If you have a torque screwdriver, refer to the “Torque” column for each step.
• Make sure that you use the correct screws. 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 that all screws are
tightened firmly.
• Ensure torque screwdrivers are calibrated correctly following country
specifications.

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 Lenovo 851

Removing and replacing an FRU

This section presents exploded figures with the instructions to indicate how to
remove and replace the FRU. Make sure to observe the following general rules:
1. Do not attempt 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 26.
3. Begin by removing any FRUs that have to be removed before the failing FRU.
Any of such FRUs are listed at the top of the section that describes the
detailed removing and replacing procedure for the failing FRU. Remove
them in the order in which they are listed.
4. Follow the correct sequence in the steps to remove the FRU, while referring
to figures provided in the procedure.
5. When turning a screw to replace an FRU, turn it in the direction as given by
the arrow in the figure.
6. When removing the FRU, move it in the direction as given by the arrow in the
figure.
7. To put the new FRU in place, reverse the removal procedures and follow any
of the notes that pertain to replacement. For information about connecting
and arranging internal cables, see “Locations” on page 76.
8. When replacing an FRU, use the correct screw as specified in the procedures.

DANGER
Before removing any FRU, turn off the computer, unplug all power cords
from electrical outlets, remove the battery pack, and then disconnect any of
the interconnecting cables.

Attention: After replacing an FRU, do not turn on the computer until you have
made sure that all screws, springs, and other small parts are in place and none
are 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 using an electrostatic discharge (ESD) strap
(P/N 6405959) to remove potential shock reasons.

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 Lenovo 851 Hardware Maintenance Manual

1010 Rear cover

1. Open the hinge frame.

Figure 1-1. Opening the hinge frame

2. Open the card slot cover using a thin flat blade or guitar pick.

Figure 1-2. Opening the card slot

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 Lenovo 851

3. Remove screws a on the rear cover as shown in the figure below.

Figure 1-3. The screws on the rear cover

Part No. Screw (quantity) Color Torque

a Phillips flat head screw, M1.4 × 1.6 (3) Silver N/A

4. Separate the bottom right corner of the rear cover from the main body of the
tablet using a suction tool as shown in the figure below.

Figure 1-4. Separating the rear cover from the main body (bottom right)

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 Lenovo 851 Hardware Maintenance Manual

5. Hold the tablet in one hand and use a guitar pick to unlock the rear cover
from the tablet along the joint line as shown in the figure below.

Figure 1-5. Unlocking the rear cover from the main body (along the joint line)

CAUTION:
Handle with care!
The rear cover or its locks can be damaged!
Do not try to lift the rear cover off the tablet when it is tightly locked at some
places. Use a guitar pick to unlock these places first.

6. Slowly remove the rear cover.

Figure 1-6. The removed rear cover

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 Lenovo 851

1020 Right speaker

For access, remove the following FRU:

• “1010 Rear cover” on page 28

1. Disconnect the power supply to the tablet by detaching the battery FPC from
its connector on the main board using a pair of tweezers.

Figure 2-1. Disconnecting the power supply of the tablet

2. Remove screws a on the holder of the right speaker as shown in the figure
below.

Figure 2-2. The screws on the holder

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 Lenovo 851 Hardware Maintenance Manual

Part No. Screw (quantity) Color Torque

a Phillips flat-head screw, M1.4 × 2.5 (3) Silver N/A

3. Detach the connector of the right speaker FPC from the sub board using a pair
of tweezers.

Figure 2-3. Detaching the FPC connector of the right speaker

4. Gently detach the side of case from the right speaker using a pair of tweezers,
and at the same time push the right speaker in the direction as shown in the
figure below.

Figure 2-4. Removing the right speaker

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 Lenovo 851

5. Remove the right speaker.

Figure 2-5. The removed right speaker

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 Lenovo 851 Hardware Maintenance Manual

1030 Sub board

Important notices for handling PCB:

When handling PCB, bear the following in mind:
• Be careful not to drop the PCB onto a bench top that has a hard surface,
such as surface made of metal, wood, or composite materials.
• Avoid rough handling of any kind.
• Make sure not to drop or stack the PCB in the whole process.
• Make sure to put the PCB only on surface covered with such materials as
an ESD mat or conductive corrugated plate.

For access, remove the following FRU:

• “1010 Rear cover” on page 28

and

Detach the following FPCs and wire connections:

• Battery FPC (see Step 1 on page 31 in “1020 Right speaker”)
• Right speaker FPC (see Step 3 on page 32 in “1020 Right speaker”)

1. Unlock the connector of the hall sensor FPC on the sub board using a guitar
pick.

Figure 3-1. Unlocking the connector of the hall sensor FPC

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 Lenovo 851

2. Pull out the hall sensor FPC from its connector using a pair of tweezers.

Figure 3-2. Pulling out the hall sensor FPC

3. Detach the connector of the main FPC from the sub board using a pair of tweezers.

Figure 3-3. Detaching the connector of the main FPC (on the sub board)

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 Lenovo 851 Hardware Maintenance Manual

4. Remove screws a on the sub board.

Figure 3-4. The screws on the sub board

Part No. Screw (quantity) Color Torque

a Phillips flat head screw, M1.4 × 1.6, wide Silver N/A
head (3)

5. Remove the sub board from the tablet using a pair of tweezers.

Figure 3-5. Removing the sub board from the tablet

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 Lenovo 851

Figure 3-6. The removed sub board

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 Lenovo 851 Hardware Maintenance Manual

1040 LCD FPC

For access, remove the following FRUs in order:
• “1010 Rear cover” on page 28

1. Unlock the connector of the LCD FPC on the front module of the tablet using a
guitar pick.

Figure 4-1. Unlocking the connector of the LCD FPC (front module side)

2. Unlock the connector of the LCD FPC on the main board using a guitar pick.

Figure 4-2. Unlocking the connector of the LCD FPC (main board side)

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 Lenovo 851

3. Pull out the LCD FPC from its connector on the main board using a pair of
tweezers.

Figure 4-3. Pulling out the LCD FPC (from the main board side)

4. Detach the LCD FPC from the front module using a pair of tweezers.

Figure 4-4. Detaching the LCD FPC from the front module

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 Lenovo 851 Hardware Maintenance Manual

5. Pull out the LCD FPC from its connector on the front module using a pair of
tweezers.

Figure 4-5. Pulling out the LCD FPC (from the front module side)

Figure 4-6. The removed LCD FPC

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 Lenovo 851

1050 Main FPC

For access, remove the following FRU:

• “1010 Rear cover” on page 28

1. Disconnect the power supply to the tablet by detaching the battery FPC from
its connector on the main board using a pair of tweezers.

Figure 5-1. Disconnecting the power supply of the tablet

2. Detach the connector of the main FPC from the sub board using a pair of
tweezers.

Figure 5-2. Detaching the connector of the main FPC (on the sub board)

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 Lenovo 851 Hardware Maintenance Manual

3. Detach the connector of the main FPC from the main board using a pair of
tweezers.

Figure 5-3. Detaching the connector of the main FPC (on the main board)

4. Remove the main FPC.

Figure 5-4. Removing the main FPC

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 Lenovo 851

Figure 5-5. The removed main FPC

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 Lenovo 851 Hardware Maintenance Manual

1060 Hall sensor FPC

For access, remove the following FRU:

• “1010 Rear cover” on page 28

1. Disconnect the power supply to the tablet by detaching the battery FPC from
its connector on the main board using a pair of tweezers.

Figure 6-1. Disconnecting the power supply of the tablet

2. Unlock the connector of the hall sensor FPC on the sub board using a guitar
pick.

Figure 6-2. Unlocking the connector of the hall sensor FPC

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 Lenovo 851

3. Pull out the hall sensor FPC from its connector using a pair of tweezers.

Figure 6-3. Pulling out the hall sensor FPC

4. Remove the hall sensor FPC using a pair of tweezers.

Figure 6-4. Removing the hall sensor FPC

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 Lenovo 851 Hardware Maintenance Manual

Figure 6-5. The removed hall sensor FPC

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 Lenovo 851

1070 Main board

Important notices for handling PCB:

When handling PCB, bear the following in mind:
• Be careful not to drop the PCB onto a bench top that has a hard surface,
such as surface made of metal, wood, or composite materials.
• Avoid rough handling of any kind.
• Make sure not to drop or stack the PCB in the whole process.
• Make sure to put the PCB only on surface covered with such materials as
an ESD mat or conductive corrugated plate.

For access, remove the following FRU:

• “1010 Rear cover” on page 28

and

Detach the following FPCs from the main board:

• Battery FPC (see Step 1 on page 31 in “1020 Right speaker”)
• LCD FPC (see Step 2 on page 38 and Step 3 on page 39 in “1040 LCD FPC”)
• Main FPC (see Step 2 on page 41 in “1050 Main FPC”)

1. Unlock the connector of the TP FPC on the main board using a guitar pick as
shown in the figure below.

Figure 7-1. Unlocking the connector of the TP FPC

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 Lenovo 851 Hardware Maintenance Manual

2. Pull out the TP FPC from its unlocked connector using a pair of tweezers.

Figure 7-2. Pulling out the TP FPC

3. Unlock the connector of the left speaker FPC on the main board using a guitar
pick.

Figure 7-3. Unlocking the connector of the left speaker FPC

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 Lenovo 851

4. Pull out the FPC of the left speaker from the unlocked connector using a pair
of tweezers.

Figure 7-4. Pulling out the FPC of the left speaker

5. Detach the connector of the USB and volume key FPC from the main board
using a pair of tweezers.

Figure 7-5. Detaching the connector of the USB and volume key FPC

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 Lenovo 851 Hardware Maintenance Manual

6. Detach the connector of the rear camera FPC from the main board using a
pair of tweezers.

Figure 7-6. Detaching the connector of the rear camera FPC

7. Remove screws a on the main board as shown in the figure below.

Figure 7-7. The screws on the main board

Part No. Screw (quantity) Color Torque

a Phillips flat head screw, M1.4 × 1.6, wide Silver N/A
head (6)

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 Lenovo 851

8. Disconnect the cable of the antennas from its connector on back of the main
board using a pair of tweezers at the positions shown in the figure below.

Figure 7-8. Positions for disconnecting the antennas

9. Remove the main board together with the attached front camera and main
FPC.

Figure 7-9. The removed main board together with the attached front camera and main FPC

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 Lenovo 851 Hardware Maintenance Manual

10. Detach the connector of the main FPC on the main board using a pair of
tweezers.

Figure 7-10. Detaching the connector of the main FPC (on the main board)

11. Remove the main FPC from the main board

Figure 7-11. Removing the main FPC from the main board

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 Lenovo 851

12. Unlock the connector of the front camera FPC on the back of main board
using a guitar pick.

Figure 7-12. Unlocking the connector of the front camera FPC

13. Remove the front camera FPC from its unlocked connector.

Figure 7-13. Removing the front camera

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 Lenovo 851 Hardware Maintenance Manual

Figure 7-14. The removed main board and front camera

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 Lenovo 851

1080 Left speaker

For access, remove the following FRUs in order:

• “1010 Rear cover” on page 28
• “1070 Main board” on page 47

1. Remove screws a on the left speaker as shown in the figure below.

Figure 8-1. The screws on the left speaker

Part No. Screw (quantity) Color Torque

a Phillips flat-head screw, M1.4 × 2.5 (3) Sliver N/A

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 Lenovo 851 Hardware Maintenance Manual

2. Remove the left speaker unit together with the attached rear camera, USB and
volume key FPC.

Figure 8-2. Removing the left speaker together with attached rear camera and USB and volume
key FPC

Figure 8-3. The removed left speaker together with attached rear camera and USB and volume
key FPC

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 Lenovo 851

3. Detach the conductive shield at the side of the rear camera using a pair of
tweezers as shown in the figure below.

Figure 8-4. Detaching the conductive shield at the side of the rear camera

4. Remove the rear camera from its conductive shield seat on the left speaker
unit as shown in the figure below.

Figure 8-5. Removing the rear camera

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 Lenovo 851 Hardware Maintenance Manual

5. Remove the USB and volume key FPC on the back of the left speaker unit
using a pair of tweezers.

Figure 8-6. Removing the USB and volume key FPC

Figure 8-7. The removed left speaker

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 Lenovo 851

1090 Rear camera

For access, remove the following FRUs in order:

• “1010 Rear cover” on page 28
• “1070 Main board” on page 47

and

Detach the following FRU:

• Left Speaker (see Step 1 on page 55 and Step 2 on page 56 in “1080 Left
speaker”)

1. Detach the conductive shield at the side of the rear camera using a pair of
tweezers as shown in the figure below.

Figure 9-1. Detaching the conductive shield at the side of the rear camera

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 Lenovo 851 Hardware Maintenance Manual

2. Remove the rear camera from its conductive shield seat on the left speaker
box by as shown in the figure below.

Figure 9-2. Removing the rear camera

Figure 9-3. The removed rear camera

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 Lenovo 851

1100 USB and volume key FPC

For access, remove the following FRUs in order:

• “1010 Rear cover” on page 28
• “1070 Main board” on page 47

and

Detach the following FRU:

• Left Speaker (see Step 1 on page 55 and Step 2 on page 56 in “1080 Left
speaker”)

1. Detach the USB and volume key FPC on the back of the left speaker unit
using a pair of tweezers.

Figure 10-1. Detaching the USB and volume key FPC

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2. Remove the USB and volume key FPC from the left speaker.

Figure 10-2. The removed USB and volume key FPC

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1110 Volume key

For access, remove the following FRUs in order:

• “1010 Rear cover” on page 28
• “1070 Main board” on page 47

and

Detach the following FRU:

• Left speaker (see Step 1 on page 55 and Step 2 on page 56 in “1080 Left
speaker”)

1. Detach the volume key using a pair of pointed tweezers.

Figure 11-1. Detaching the volume key

2. Remove the volume key.

Figure 11-2. The removed volume key

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1120 WIFI2 antenna

For access, remove the following FRU:

• “1010 Rear cover” on page 28
• “1070 Main board” on page 47

1. Remove screw a on the WIFI2 antenna as shown in the figure below.

Figure 12-1. The screw on the antenna

Part No. Screw (quantity) Color Torque

a Phillips flat-head screw, M1.4 × 1.5 (3) Black N/A

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2. Remove the WIFI2 antenna.

Figure 12-2. The removed antenna

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1130 GPS/WIFI1 antenna

For access, remove the following FRU:

• “1010 Rear cover” on page 28
• “1070 Main board” on page 47

1. Remove screw a on the GPS/WIFI1 antenna as shown in the figure below.

Figure 13-1. The screw on the antenna

Part No. Screw (quantity) Color Torque

a Phillips flat-head screw, M1.4 × 1.5 (3) Black N/A

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2. Remove the GPS/WIFI1 antenna.

Figure 13-2. The removed antenna

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1140 Windows key

For access, remove the following FRU:

• “1010 Rear cover” on page 28
• “1020 Right speaker” on page 31

1. Detach the windows key using a pair of pointed tweezers.

Figure 14-1. Detaching the windows key

2. Remove the windows key.

Figure 14-2. The removed windows key

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1150 Battery pack

For access, remove the following FRUs in order:

• “1010 Rear cover” on page 28
• “1020 Right speaker” on page 31

Rechargeable Battery Notice

CAUTION:
Risk of explosion if the battery is replaced with an incorrect type.
When replacing the lithium battery, use only the same or an equivalent type
that is recommended by the manufacturer. The battery contains lithium and
can explode if not properly used, handled, or disposed of.
Dispose of the used battery according to the instructions. Do not:
• Throw or immerse into water
• Heat to more than 100°C (212°F)
• Repair or disassemble

1. Disconnect the battery FPC from its connector on the main board using a pair
of tweezers.

Figure 15-1. Disconnecting the battery FPC

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2. Slowly pull out the hinge pivot using a pair of tweezers.

Figure 15-2. Pulling out the hinge pivot

Figure 15-3. The removed hinge pivot

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3. Detach the hinge frame at the left end, turn the hinge frame clockwise around
its right end so as to steer the battery FPC out through the supporting frame
at the right end, and then remove the hinge frame from the main body of the
tablet.

Figure 15-4. Removing the hinge frame with the battery pack

4. Peel off the foil on the battery cover at the FPC end of the hinge frame.

Figure 15-5. Peeling off the foil on the battery cover

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5. Remove screw a on the battery cover as shown in the figure below.

Figure 15-6. The screw on the battery cover

Part No. Screw (quantity) Color Torque

a Phillips flat-head screw, M1.4 × 3.0 (1) Silver N/A

6. Remove the battery cover as shown in the figure below.

Figure 15-7. Removing the battery cover

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7. Remove the battery pack from the hinge frame.

Figure 15-8. Removing the battery pack

Figure 15-9. The removed battery pack

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1160 Power key

For access, remove the following FRUs in order:

• “1010 Rear cover” on page 28
• “1070 Main board” on page 47

and

Detach the following FRU:

• Left speaker (see Step 1 on page 55 and Step 2 on page 56 in “1080 Left
speaker”)

1. Push out the power button as shown in the figure below.

Figure 16-1. Pushing out the power key

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2. Remove the power key.

Figure 16-2. The removed power key

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Locations

Front view

Front camera
Left speaker
Right speaker

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Rear view

Audio Jack
Windows key
Microphone
Micro-SD card slot
Volume key
Micro-USB connection
Rear camera
Power key

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Parts list

This section presents the following service parts:

• “Overall” on page 78
• “Screws” on page 82

Overall

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Table 1. Parts list–Overall

No. FRU FRU No. CRU ID

1 851 front module (TP LCM assembly) 5D69A6N368 N

5D69A6N4KH
5D69A6N2YU
2 851 rear cover 5S59A6N366 N
3 851 battery 5B19A6MWSH N
(battery cell)
5B19A6N367
(battery pack)
4 851 hinge frame 5M89A6MXJP N
(black)
5M89A6N049
(black)
5S59A6MXJS
5 851 battery cover (right) 5D79A6MXKU N
(black)
6 851 power key 5B69A6MXHS N
(black)
5B69A6N07P
(black)
7 851 rear camera 8.0MP AF OV8865 5C29A6MWJ3 N
5C29A6N016
8 851 front camera 1.6MP 25PIN 3P FF 5C29A6MWJ8 N
5C29A6MWJ9
9 851 main board 5B29A6N369 N
(32G)
10 851 hinge pivot 5SR9A6MXK6 N
11 851 left speaker 5SB9A6MXFN N
5SB9A6MXFH
12 851 WIFI2 antenna SA39A6N1MX N
13 851 right speaker 5SB9A6N061 N
5SB9A6N062
14 851 LCD FPC 5F79A6MX4F N
5F79A6MXBG
15 851 card slot cover 5S59A6MXJT N
(black)
16 851 windows key 5B69A6MYF5 N
(black)
5B69A6N07M
(black)
17 851 GPS/WIFI1 antenna 5A39A6MYKH N
18 851 USB and volume key FPC 5F79A6MWDL N
5F79A6MXBF
19 851 main FPC 5F79A6MWDM N
5F79A6MXBE
20 851 sub board 5P69A6MX74 N

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21 851 hall sensor FPC 5F79A6MX4D N

5F79A6MXBH
22 851 volume key 5B69A6MXHT N
5B69A6N07S
23 851 battery cover (left) 5D79A6MXKT N
(black)

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Screws

Table 2. Parts list–Screw

FRU P/N CRU ID

Phillips cross head screw, M1.4 × 2.5 SM89A44142 N

Phillips cross head screw, M1.4 × 3.0 SM89A44143 N
Phillips cross head screw, M1.4 × 1.5 5M89A4675Y N
Phillips cross head screw, M1.4 × 1.6 5M89A6N02R N

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 Notices

Notices
Lenovo may not offer the products, services, or features discussed in this
document in all countries. Consult your local Lenovo representative for
information on the products and services currently available in your area. Any
reference to a Lenovo product, program, or service is not intended to state or
imply that only that Lenovo product, program, or service may be used. Any
functionally equivalent product, program, or service that does not infringe any
Lenovo intellectual property right may be used instead. However, it is the user’s
responsibility to evaluate and verify the operation of any other product,
program, or service.
Lenovo may have patents or pending patent applications covering subject
matter described in this document. The furnishing of this document does not
give you any license to these patents.

LENOVO GROUP LTD. PROVIDES THIS PUBLICATION “AS IS” WITHOUT

WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF NON-
INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE. Some jurisdictions do not allow disclaimer of express or implied
warranties in certain transactions, therefore, this statement may not apply to
you.
This information 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. Lenovo may make
improvements and/or changes in the product(s) and/or the program(s) described
in this publication at any time without notice.
The products described in this document are not intended for use in
implantation or other life support applications where malfunction may result in
injury or death to persons. The information contained in this document does not
affect or change Lenovo product specifications or warranties. Nothing in this
document shall operate as an express or implied license or indemnity under the
intellectual property rights of Lenovo or third parties. All information contained
in this document was obtained in specific environments and is presented as an
illustration. The result obtained in other operating environments may vary.
Lenovo may use or distribute any of the information you supply in any way it
believes appropriate without incurring any obligation to you.
Any references in this publication to non-Lenovo Web sites are provided for
convenience only and do not in any manner serve as an endorsement of those
Web sites. The materials at those Web sites are not part of the materials for this
Lenovo product, and use of those Web sites is at your own risk.

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Any performance data contained herein was determined in a controlled

environment. Therefore, the result obtained in other operating environments
may vary significantly. Some measurements may have been made on
development-level systems and there is no guarantee that these measurements
will be the same on generally available systems. Furthermore, some
measurements may have been estimated through extrapolation. Actual results
may vary. Users of this document should verify the applicable data for their
specific environment.

Trademarks

Lenovo and the Lenovo logo are trademarks of Lenovo in the United States or
other countries, or both.
Other company, product, or service names may be trademarks or service marks
of others.

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