Dell latitude c540, latitudec640 schematic

Dell Latitude C540/C640 Service Manual

Dell™ Latitude™ C540/C640 Service
Manual

Before You Begin
System Components
Hard Drive
Memory Modules, Mini PCI Card, and Modem
Keyboard
Display Assembly, Display Latch, and Hinge Covers
Palm Rest
Microprocessor Thermal Cooling Assembly
Microprocessor Module
Hybrid Cooling Fan
Reserve Battery
Flashing the BIOS
Speaker Assemblies
System Board
Battery and Module Bay Latches
Pin Assignments for I/O Connectors

Notes, Notices, and Cautions

NOTE: A NOTE indicates important information that helps you make better use

of your computer.

NOTICE: A NOTICE indicates either potential damage to hardware or loss of

data and tells you how to avoid the problem.

CAUTION: A CAUTION indicates a potential for property damage,

personal injury, or death.

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Dell Latitude C540/C640 Service Manual

Trademarks used in this text: Dell, the DELL logo, and Latitude are trademarks of Dell Computer
Corporation.

Other trademarks and trade names may be used in this document to refer to either the entities
claiming the marks and names or their products. Dell Computer Corporation disclaims any proprietary
interest in trademarks and trade names other than its own.

April 2003 Rev. A01

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Before You Begin: Dell Latitude C540/C640 Service Manual

Back to Contents Page

Before You Begin

Dell™ Latitude™ C540/C640 Service Manual

Preparing to Work Inside the Computer
Recommended Tools
Screw Identification

Preparing to Work Inside the Computer

CAUTION: Before working inside your computer, read the safety

instructions in your System Information Guide.

CAUTION: Only a certified service technician should perform repairs on

your computer. Damage due to servicing that is not authorized by Dell
is not covered by your warranty.

NOTICE: To avoid damaging the computer, perform the following steps before

you begin working inside the computer.

1. Ensure that the work surface is clean to prevent scratching the computer cover.

2. Save any work in progress and exit all open programs.

3. Turn off the computer and all attached devices.

NOTE: Before turning off the computer, ensure that the computer is not in a

power management mode. If you cannot shut down the computer using the
computer operating system, press and hold the power button for 4 seconds.

4. If the computer is connected (docked) to a docking device, undock it. See the
documentation that came with the docking device for instructions.

5. Disconnect the computer and any attached devices from electrical outlets.

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Before You Begin: Dell Latitude C540/C640 Service Manual

6. To avoid possible damage to the system board, wait 10 to 20 seconds and then
disconnect any attached devices.

7. Disconnect all other external cables from the computer.

8. Remove any installed PC Cards or plastic blanks from the PC Card slot.

9. Close the display and turn the computer upside down on a flat work surface.

NOTICE: To avoid damaging the system board, you must remove the main

battery and secondary battery (if present) before you service the computer.

10. Remove the primary battery from the battery bay and the secondary battery
from the module bay, if a secondary battery is in use.

11. Remove any installed device in the module bay.

12. To dissipate any static electricity while you work, use a wrist grounding strap or
periodically touch an unpainted metal surface.

13. Handle components and cards with care. Do not touch the components or
contacts on a card. Hold a card by it edges or by its metal mounting bracket.
Hold a component such as a microprocessor by its edges, not by its pins.

Recommended Tools

The procedures in this manual require the following tools:

● #1 magnetized Phillips screwdriver

● ¼-inch flat-blade screwdriver

● Small plastic scribe

● Microprocessor extractor

● Flash BIOS update program floppy disk or CD.

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Before You Begin: Dell Latitude C540/C640 Service Manual

Computer Orientation

1 back
2 right
3 front
4 left

Screw Identification

When you are removing and replacing components, photocopy the placemat as a tool
to lay out and keep track of the screws. The placemat provides the number of screws
and their sizes.

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Before You Begin: Dell Latitude C540/C640 Service Manual

NOTICE: When reinstalling a screw, you must use a screw of the correct

diameter and length. Ensure that the screw is properly aligned with its
corresponding hole, and avoid overtightening.

Hard Drive Door:

(1 each)

Memory Module Cover:

(2 captive screws)

(1 each)

NOTE: The single screw is

one of the five keyboard
screws.

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Before You Begin: Dell Latitude C540/C640 Service Manual

Modem to
System Board:

(2 each)

Keyboard to
Bottom Case:

(5 each)

Hinges to Bottom Case:

(5 each)

Display-Feed Flex Cable:

(4 each)

Display Bezel:

(6 each)

Rubber Screw Covers (6
each)

Display Panel to Top
Cover:

(5 each)

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Before You Begin: Dell Latitude C540/C640 Service Manual

Display Latch:

(2 each) (2 each)

Palm Rest to
Bottom Case:

(3 each) (5 each)

Hybrid Cooling Fan:

(2 each) (1 each)

System Board to Bottom
Case:

(10 each)

Back to Contents Page

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System Components: Dell Latitude C540/C640 Service Manual

Back to Contents Page

System Components

Dell™ Latitude™ C540/C640 Service Manual

NOTICE: Only a certified service technician should perform repairs on your

computer. Damage due to servicing that is not authorized by Dell is not covered
by your warranty.

NOTICE: Unless otherwise noted, each procedure in this document assumes

that a part can be replaced by performing the removal procedure in reverse
order.

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System Components: Dell Latitude C540/C640 Service Manual

1 display assembly 10 bottom case
2 center control cover 11 memory module

cover

3 microprocessor thermal

cooling assembly

12 module bay device

4 hybrid cooling fan 13 main battery
5 microprocessor 14 hard drive
6 system board 15 left speaker
7 right speaker 16 palm rest
8 modem and network-adapter

connector cover

17 keyboard

9 fan guard

Back to Contents Page

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Hard Drive: Dell Latitude C540/C640 Service Manual

Back to Contents Page

Hard Drive

Dell™ Latitude™ C540/C640 Service Manual

Removing the Hard Drive

1. Save and close any open files, exit any open programs, and then shut down the
computer.

NOTICE: Disconnect the computer and any attached devices from electrical

outlets, and remove any installed batteries.

NOTICE: The hard drive is very sensitive to shock. Handle the hard drive by its

edges (do not squeeze the top of the hard drive case), and avoid dropping it.

NOTICE: Read "Preparing to Work Inside the Computer" before performing the

following procedure.

NOTICE: To prevent data loss, turn off your computer before removing the

hard drive. Do not remove the hard drive while the computer is running, in
standby mode, or in hibernate mode.

CAUTION: If you remove the hard drive from the computer when the

drive is hot, do not touch the metal housing of the hard drive.

2. Ground yourself by touching a metal connector on the back of the computer.

3. Turn the computer over. Remove the M3 x 5-mm screw from the hard drive
door.

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Hard Drive: Dell Latitude C540/C640 Service Manual

1 bottom of computer
2 M3 x 5-mm screw
3 hard drive door

4. Lift the hard drive door until you hear a click.

5. Slide the hard drive out of the computer.

Replacing the Hard Drive

NOTICE: Use firm and even pressure to slide the hard drive into place. If you

force the hard drive into place using excessive force, you may damage the
connector.

1. Lift the hard drive door until you hear a click. Push the hard drive until it is fully
seated in the hard drive bay.

2. Press the hard drive door down.

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Hard Drive: Dell Latitude C540/C640 Service Manual

3. Replace the M3 x 5-mm screw in the hard drive door.

Back to Contents Page

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Memory Modules, Mini PCI Card, and Modem: Dell Latitude C540/C640 Service Manual

Back to Contents Page

Memory Modules, Mini PCI Card, and
Modem

Dell™ Latitude™ C540/C640 Service Manual

Memory Modules
Mini PCI Card
Modem

Memory Modules

Removing the Memory Module Cover

NOTICE: Disconnect the computer and any attached devices from electrical

outlets, and remove any installed batteries.

NOTICE: To avoid ESD, ground yourself by using a wrist grounding strap or by

touching an unpainted metal surface on the computer.

NOTICE: Read "Preparing to Work Inside the Computer" before performing the

following procedure.

1. Turn the computer over and loosen the two captive screws from the memory
module cover.

2. Remove the M2.5 x 12-mm screw labeled "circle K" from the memory module
cover. (This screw is also one of the five keyboard screws.)

3. Place your finger under the cover at the indentation and lift and slide the cover
open.

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Memory Modules, Mini PCI Card, and Modem: Dell Latitude C540/C640 Service Manual

1 M2.5 x 12-mm screw

(1)

2 captive screws (2)

Removing the Memory Modules

NOTICE: Disconnect the computer and any attached devices from electrical

outlets, and remove any installed batteries.

NOTICE: To avoid ESD, ground yourself by using a wrist grounding strap or by

touching an unpainted metal surface on the computer.

NOTICE: Read "Preparing to Work Inside the Computer" before performing the

following procedure.

1. Remove the

memory module cover.

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Memory Modules, Mini PCI Card, and Modem: Dell Latitude C540/C640 Service Manual

NOTICE: To prevent damage to the memory module connector, do not use

tools to spread the inner metal tabs that secure the memory module.

2. Use your fingertips to carefully spread apart the inner tabs on each end of the
memory module socket. The module should pop up.

1 JDIM 2 memory socket
2 JDIM 1 memory socket
3 keying tab
4 keying notch
5 inner tabs (2 per socket)

3. Lift the memory module out of its socket.

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Memory Modules, Mini PCI Card, and Modem: Dell Latitude C540/C640 Service Manual

Replacing the Memory Modules

1. If you only have one memory module, install it in the connector labeled "JDIM1"
on the system board. Install a second memory module in the connector labeled
"JDIM2."

NOTE: Memory modules are keyed, or designed to fit into their sockets, in only

one direction.

NOTICE: The memory module must be inserted at a 45-degree angle to avoid

damaging the connector.

2. Align the notch in the memory-module edge connector with the tab in the
socket.

3. Slide the edge connector of the module firmly into the socket at a
45-degree angle, and rotate the module down until it clicks into place. If you do
not feel the click, remove the module and reinstall it.

4. Replace the memory module cover and tighten the two captive screws.

Mini PCI Card

You must remove the Mini PCI card before the system board can be removed.

Removing the Mini PCI Card

NOTICE: Disconnect the computer and any attached devices from electrical

outlets, and remove any installed batteries.

NOTICE: To avoid ESD, ground yourself by using a wrist grounding strap or by

touching an unpainted metal surface on the computer.

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Memory Modules, Mini PCI Card, and Modem: Dell Latitude C540/C640 Service Manual

NOTICE: Read "Preparing to Work Inside the Computer" before performing the

following procedure.

1. Remove the

memory module cover, which also covers the Mini-PCI card.

2. Disconnect the Mini PCI card from the antenna cables.

3. To release a Mini PCI card from its socket, spread apart the metal securing tabs
until the card pops up slightly.

4. Lift the Mini PCI card out of its connector.

1 antenna connectors on

card (2)

2 antenna cables (2)

Replacing the Mini PCI Card

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Memory Modules, Mini PCI Card, and Modem: Dell Latitude C540/C640 Service Manual

1. Align the Mini PCI card with the socket at a 45-degree angle, and press the Mini
PCI card into the socket.

NOTICE: The connectors are keyed for correct insertion; do not force the

connections.

2. Pivot the Mini PCI card down until it snaps into the inner tabs of the socket.

3. Attach the antenna cables to the Mini PCI card.

4. Replace the memory module cover and tighten the two captive screws.

Modem

Removing the Modem

NOTICE: Disconnect the computer and any attached devices from electrical

outlets, and remove any installed batteries.

NOTICE: To avoid ESD, ground yourself by using a wrist grounding strap or by

touching an unpainted metal surface on the computer.

NOTICE: Read "Preparing to Work Inside the Computer" before performing the

following procedure.

1. Turn the computer over, and remove the

memory module cover, which also

covers the modem.

2. Remove the two M2 x 3-mm screws that secure the modem to the system
board.

NOTICE: Do not pull on the modem cable. Pull from the modem connector to

disconnect the cable.

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Memory Modules, Mini PCI Card, and Modem: Dell Latitude C540/C640 Service Manual

3. Pull straight up on the attached pull-tab to lift the modem out of its connector
on the system board and disconnect the modem cable.

1 M2 x 3-mm screws (2)
2 modem connector
3 modem cable
4 pull-tab

Replacing the Modem

1. Connect the modem cable to the modem.

NOTICE: The connectors are keyed for correct insertion; do not force the

connections.

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Memory Modules, Mini PCI Card, and Modem: Dell Latitude C540/C640 Service Manual

2. Align the modem with the screw holes on the system board and press down on
the pull-tab to seat the modem in the connector.

NOTICE: Pressing down on the modem somewhere other than on the pull-tab

can break the modem.

3. Install the two M2 x 3-mm screws that secure the modem to the system board.

4. Replace the

memory module cover and tighten the two captive screws.

Back to Contents Page

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Keyboard: Dell Latitude C540/C640 Service Manual

Back to Contents Page

Keyboard

Dell™ Latitude™ C540/C640 Service Manual

Removing the Keyboard

NOTICE: Disconnect the computer and any attached devices from electrical

outlets, and remove any installed batteries.

NOTICE: To avoid ESD, ground yourself by using a wrist grounding strap or by

touching an unpainted metal surface on the computer.

NOTICE: Read "Preparing to Work Inside the Computer" before performing the

following procedure.

1. Remove the

hard drive.

2. Turn the computer over, and remove the five M2.5 x 12-mm screws labeled
"circle K."

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Keyboard: Dell Latitude C540/C640 Service Manual

1 M2.5 x 12-mm screws

(5)

3. Turn the computer over and open the display.

NOTICE: The keycaps on the keyboard are fragile, easily dislodged, and time-

consuming to replace. Be careful when removing and handling the keyboard.

4. Remove the center control cover:

a. Insert a small, flat-blade screwdriver or plastic scribe into the notch at the

right end of the center control cover and pry up the cover.

b. Lift the center control cover up and away from the bottom case.

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Keyboard: Dell Latitude C540/C640 Service Manual

5. To release the keyboard from the palm rest, use a small, flat-blade screwdriver
or plastic scribe to pry up the right edge of the keyboard near the blank key.

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