Dell C400 User Manual

Dell™ Latitude™ C400 Service Manual

Before You Begin
System Components
Keyboard
Memory Module and Modem Daughter Card
Hard Drive
Wireless Network Adapter
Display Assembly and Display Latch
Palm Rest
Cooling Fan
Reserve Battery
Flashing the BIOS
Audio Board
System Board
Battery Latch
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.

Information in this document is subject to change without notice.
© 2001 Dell Computer Corporation. All rights reserved.

Reproduction in any manner whatsoever without the written permission of Dell Computer Corporation is strictly forbidden.
Trademarks used in this text: Dell, the DELL logo, and Latitude are trademarks of Dell Computer Corporation; Intel is a registered trademark of

Intel Corporation; Microsoft and Windows are registered trademarks of Microsoft 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.
October 2001 Rev. A00

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Before You Begin

Dell™ Latitude™ C400 Service Manual

Preparing to Work Inside the Computer
Recommended Tools
Screw Identification

Preparing to Work Inside the Computer

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: To avoid damaging the computer, perform the following steps before you begin working inside the computer.

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

2. Save any work in progress and close all open application programs.

3. Turn off the computer and all attached devices.

NOTE: Make sure the computer is turned off and not in suspend-to-disk or hibernate mode. If you cannot shut

down the computer using the computer's operating system, press and hold the power button for 4 seconds.

4. Make sure the computer is undocked.

5. Disconnect the computer from the electrical outlet.

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, including the IDE modular bay cable (if connected).

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 battery before you service the computer.

10. Remove the battery from the battery bay.

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

12. 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 internal components by their edges, not by their pins.

Recommended Tools

The procedures in this manual require the following tools:

#1 magnetized Phillips screwdriver
Small flat-blade screwdriver

5-mm nut driver
7-mm nut driver
Needle-nose pliers
Flash BIOS update program floppy disk or CD

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.

Screw Identification

NOTICE: When reinstalling a screw, you must use a screw of the correct diameter and length. Make sure that the

screw is properly aligned with its corresponding hole, and avoid overtightening.

Hard Drive Door:

Modem Daughter Card:

(1 each)

Keyboard:
(4 each)

Display Bezel:
(6 each)

(1 each)

Display Assembly:

Palm Rest to Bottom Case:

Rubber screw covers: 6 each

Critical Component Shield:
(6 each)

Cooling Fan:
(3 each)

Palm Rest to System Board:
(6 each)

Audio Board:
(2 each)

System Board:
(1 each)

Guide pins: 2 each
5-mm hex nuts: 4 each
7-mm hex nuts: 2 each

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System Components

Dell™ Latitude™ C400 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 manual assumes that a part can be replaced by performing

the removal procedure in reverse order.

System Components

1 display 8 memory module/modem cover
2 center cover 9 battery
3 hard drive 10 audio card
4 cooling fan 11 audio card shield
5 reserve battery 12 critical component shield
6 system board 13 palm rest
7 bottom case 14 keyboard

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Keyboard

Dell™ Latitude™ C400 Service Manual

Removing the Keyboard
Replacing the Keyboard

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

NOTICE: The key caps on the keyboard are fragile, easily dislodged, and time-consuming to replace. Be careful when

removing and handling the keyboard.

2. Turn the computer right-side up and remove the center cover.

Center Cover Removal

.

1 center cover

a. Open the computer all the way (180 degrees) so that it lies flat against your work surface.
b. Press and hold down the <F4> and <F5> keys to reveal the left release slot of the center cover.

NOTE: To protect the keycaps, it may be helpful to place a straightedge (such as a short ruler) across the first

row or two of keycaps, and press on the straightedge instead of on the keycaps themselves.

c. Insert a flat-blade screwdriver into the slot. While holding the screwdriver, make your hand into a fist, brace

your knuckles against the keyboard, and pry up the center cover.
d. Repeat steps b and c for the right release slot, located behind the <F9> and <F10> keys.
e. Lift the center cover up and away from the bottom case.

3. Remove the four M2 x 4-mm screws that secure the back edge of the keyboard.

Keyboard Screws

1 M2 x 4-mm screws (4)
2 keyboard locator tab
3 keyboard securing tabs (5)

4. Pry up the keyboard locator tab, lift the back edge of the keyboard slightly, and then pull the keyboard a small distance
toward the back of the computer to release the five securing tabs located across the front edge of the keyboard.

5. Rotate the keyboard toward the front of the computer and place it face-down on the palm rest.

NOTICE: Do not pull on the keyboard flex cable.

Keyboard Removal

1 keyboard flex cable

6. Use the pull tab to pull the keyboard flex cable up from its connector on the system board.

The keyboard is now disconnected from the bottom case.

Replacing the Keyboard

1. Replace the hard drive.

2. Place the keyboard face-down on the palm rest, with the keyboard flex cable pointing toward the back of the computer.

NOTICE: To avoid damage to the connector pins, press the keyboard flex cable connector evenly into the interface

connector on the system board, and do not reverse the keyboard connector.

3. Connect the keyboard flex cable to its interface connector on the system board.

To aid with proper flex cable connection, a white locator line has been added near the end of the flex cable. Press the
cable into the connector until the white line disappears and hold it steady while you snap the flex cable connector down.
(The white line may reappear after the connector is closed; this should not indicate a problem with the connection.)

NOTICE: Position the keyboard flex cable so that it is not pinched when you replace the keyboard in the bottom case.

Keyboard Replacement

1 keyboard securing tabs (5)

4. Carefully rotate the keyboard back and fit it into the bottom case.

Ensure that all five securing tabs are engaged in their respective slots before trying to completely seat the keyboard.
Fitting the tabs to the slots may be easiest when viewed from above and slightly behind the front edge of the keyboard.
Press down on the left and right <ALT> keys to help control tab/slot alignment.

When the keyboard appears to be completely seated, confirm that the front edge of the keyboard is aligned with the
edge of the palm rest before proceeding.

5. Replace the four M2 x 4-mm screws at the back of the keyboard.

6. Replace the center cover.

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Memory Module and Modem Daughter Card

Dell™ Latitude™ C400 Service Manual

Removing the Memory Module/Modem Cover
Removing the Memory Modules
Replacing the Memory Modules
Removing the Modem Daughter Card
Replacing the Modem Daughter Card

Removing the Memory Module/Modem Cover

NOTE: This procedure covers removing and replacing the memory module located under the memory module/modem

cover on the bottom of the computer. A second memory module resides on the upper surface of the system board
under the critical component shield. To replace the memory module under the critical component shield, perform the
procedure for removing the palm rest
memory module.

NOTICE: Disconnect the computer and any attached devices from electrical outlets, and remove any installed

batteries.

up to and including removal of the critical component shield. Then replace the

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 use a #1 Phillips screwdriver to release the two captive screws from the memory
module/modem cover.

2. Place your finger under the cover at the indentation, rotate the cover open, and remove it.

Memory Module/Modem Cover

Removing the Memory Modules

NOTICE: Disconnect the computer and any attached devices from electrical outlets, and remove the battery.

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/modem cover

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.

Memory Module Removal

.

1 memory module socket
2 inner tabs (2)

3. Lift the memory module out of its socket.

Replacing the Memory Modules

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.

1. Align the notch in the memory module with the slot in the center of the socket.

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

3. Replace the cover and tighten the two captive screws.

Removing the Modem Daughter Card

NOTICE: Disconnect the computer and any attached devices from electrical outlets, and remove the battery.

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/modem cover

2. Remove the M2 x 4-mm screw that secures the modem daughter card to the system board.

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

3. Use the pull tab to pull the modem daughter card straight up out of its connector.

4. Disconnect the modem cable from the modem daughter card.

.

Modem Daughter Card Removal

1 M2 x 4-mm screw (1)

2 pull tab
3 boss
4 modem connector
5 modem cable

Replacing the Modem Daughter Card

1. Connect the modem cable to the modem daughter card.

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

2. Using the screw hole and the boss at the opposite corner of the daughter card to align the card, press the card into its
connector on the system board.

3. Install the M2 x 4-mm screw that secures the modem to the system board.

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

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Hard Drive

Dell™ Latitude™ C400 Service Manual

Removing the Hard Drive
Replacing the Hard Drive

Removing the Hard Drive

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

NOTICE: Disconnect the computer and any attached devices from electrical outlets, and remove the battery.

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 on, 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 M2.5 x 12-mm screw from the hard drive door.

Hard Drive Removal

1 bottom of computer
2 M2.5 x 12-mm screw (1)
3 hard drive door

4. Slide the hard drive straight 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. Push the hard drive into the drive bay until it is fully seated in the bay.

2. Replace the M2.5 x 12-mm screw in the hard drive door.

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Wireless Network Adapter

Dell™ Latitude™ C400 Service Manual

Removing the Wireless Network Adapter
Replacing the Wireless Network Adapter

Removing the Wireless Network Adapter

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. Remove the keyboard

Wireless Network Adapter

.

.

1 wireless cables (2)
2 wireless cable connectors (2)

3. Disconnect the two wireless cables from the wireless card.

4. Spread the two metal securing tabs apart, and pull the card from its socket.

Replacing the Wireless Network Adapter

The wireless card is keyed to the connector. Make sure the card is fully seated in the socket before attempting to pivot it

down into place.

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Display Assembly and Display Latch

Dell™ Latitude™ C400 Service Manual

Removing the Display Assembly
Replacing the Display Latch

Removing the Display Assembly

NOTICE: You must remove the display assembly before you remove the palm rest.

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 battery.

2. Remove the hard drive.

3. Remove the center cover

4. Close the display.

5. Turn the computer over and remove the two M2.5 x 6-mm screws at the bottom back corners of the computer.

Display Screws

.

1 M2.5 x 6-mm screws (2)

6. Turn the computer right-side up and open the display 180 degrees.

Display Assembly

1 display-feed flex cable
2 M2.5 x 12-mm screws (2)
3 display-feed flex cable hold-down board
4 pull tab

7. Remove the two M2.5 x 12-mm screws from the display-feed flex cable hold-down board.

8. Use the pull tab to disconnect the display-feed flex cable from its connector on the system board.

9. Move the display assembly to an upright position and pull it up out of the computer.

Replacing the Display Latch

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.

To replace the display latch, you must replace the whole bezel.

1. Remove the battery.

2. Remove the hard drive

3. Open the display 180 degrees, and remove the six rubber screw covers and the six M2 x 4-mm screws that secure the
bezel.

.

Bezel Removal

1 bezel
2 display latch
3 M2 x 4-mm screw (6)
4 display assembly

4. Use a small flat-blade screwdriver to carefully pry around the perimeter of the bezel until the bezel separates from the
display assembly.

5. Install the new bezel.

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Palm Rest

Dell™ Latitude™ C400 Service Manual

Removing the Palm Rest
Replacing the Palm Rest

Removing the Palm Rest

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. Remove the keyboard

NOTICE: You must remove the display assembly before you remove the palm rest; the display hinges pass through

the back of the palm rest.

3. Remove the display assembly

4. Turn the computer over and remove the four M2.5 x 6-mm screws (two screws to each side of the battery bay).

Palm-Rest Screws on Bottom of Computer

.

.

.

1 M2.5 x 6-mm screws (4)
2 M2.6 x 1.8-mm screws (4)
3 M2 x 4-mm screws (2)
4 M2.5 x 6-mm screws (2)

5. Remove the four M2.6 x 1.8-mm screws located inside the battery bay.

6. Remove the two M2.5 x 6-mm screws located near the service tag at the back edge of the computer.

7. Turn the computer over and remove the two M2 x 4-mm screws located above the serial, docking, and video
connectors on the back panel.

Critical Component Shield

1 M2 x 4-mm screws (6) (one screw may be captive)
2 critical component shield

8. Remove the six M2 x 4-mm screws (one of which may be captive) that secure the critical component shield to the
system board, and lift the shield away.

NOTE: At this point, the memory module under the critical component shield can be replaced.

Palm Rest Removal

1 M2.5 x 6-mm screws (6)
2 LED cable
3 palm-rest flex cable

9. Remove the six M2.5 x 6-mm screws that secure the palm rest to the system board.

10. Disconnect the LED and palm-rest flex cables.

11. If a Mini PCI wireless card is installed, disconnect the two wireless cables

12. Lift the palm rest away.

from the card.

Replacing the Palm Rest

To aid with proper flex cable connection, a white locator line has been added near the ends of the flex cables. When replacing
the LED and palm-rest flex cables, press the cable into the connector until the white line disappears and hold it steady while
you snap the flex cable connector down. (The white line may reappear after the connector is closed; this should not indicate a
problem with the connection.)

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Cooling Fan

Dell™ Latitude™ C400 Service Manual

Removing the Cooling Fan

Removing the Cooling Fan

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. Remove the keyboard

3. Remove the display assembly

4. Remove the palm rest

Cooling Fan Removal

.

.

.

.

1 cooling fan
2 M2.5 x 6-mm screws (3)
3 fan cable
4 fan extender cable

5. Remove the fan cable from the fan extender cable that runs under the system board.

6. Remove the three M2.5 x 6-mm screws that secure the cooling fan.

7. Lift out the cooling fan.

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Reserve Battery

Dell™ Latitude™ C400 Service Manual

Removing the Reserve Battery
Replacing the Reserve Battery

Removing the Reserve Battery

NOTICE: The reserve battery provides power to the computer's RTC and NVRAM when the computer is turned off.

Removing the battery causes the computer to lose the date and time information as well as all user-specified
parameters in the BIOS. If possible, make a copy of this information before you remove the reserve battery.

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. Remove the keyboard

3. Remove the display assembly

4. Remove the palm rest

Reserve Battery Removal

.

.

.

.

1 reserve battery connector on system board
2 reserve battery cable
3 reserve battery

5. Disconnect the reserve battery cable from the system board connector.

6. Pry the reserve battery free from the system board. The reserve battery is attached to the system board with a piece
of adhesive tape.

7. Remove any remnants of the adhesive tape from the system board.

Replacing the Reserve Battery

1. Connect the reserve battery cable to the system board connector.

2. Press the reserve battery into place on the system board.

3. Update the BIOS using a flash BIOS update program floppy disk or CD. For instructions on how to flash the BIOS, see
"Flashing the BIOS

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Flashing the BIOS

Dell™ Latitude™ C400 Service Manual

Perform the following steps to update the BIOS:

1. Make sure that the AC adapter is plugged in and that the main battery is installed properly.

2. Turn on the computer. The following error message appears:

System hardware failures: #0010
Strike the F1 key to shutdown

3. Instead of pressing <F1>, insert the Flash BIOS update floppy disk or CD into the appropriate drive and press <F6>,
and then press <F4>. The computer displays the following message on the screen:

Failure override
Processor update failure. Reload current BIOS
Strike the F1 key to continue, F2 to run the setup utility.

4. Press <F1>. The computer continues to boot and updates the new BIOS.

5. Press <F2> to enter the system setup program and reset the boot sequence with the appropriate drive, if required.

6. Press <ESC> to exit the system setup program.

7. Remove the Flash BIOS update floppy disk or CD from the drive and restart the computer.

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Audio Board

Dell™ Latitude™ C400 Service Manual

Removing the Audio Board
Replacing the Audio Board

Removing the Audio Board

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. Remove the keyboard

3. Remove the display assembly

4. Remove the palm rest

Audio Board Removal

.

.

.

.

1 M2 x 4-mm screws (2)
2 audio board shield
3 audio board

5. Remove the two M2 x 4-mm screws from the audio board shield, and remove the shield.

6. Pull the audio board up out of its connector.

Replacing the Audio Board

The audio board can be easily misaligned. When replacing it, first align the two screw holes in the board with the holes in the
bosses. Then, as you press the audio board into the connector, sight sideways between the audio board and the system board
to ensure that all pins on the audio board connector are headed correctly into the system board connector.

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System Board

Dell™ Latitude™ C400 Service Manual

Removing the System Board
Replacing the System Board

Removing the System Board

The system board's BIOS chip contains the service tag sequence, which is also visible on a barcode label on the bottom of the
computer. The replacement kit for the system board may include a CD that provides a utility for transferring the service tag
sequence to the replacement system board.

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 PC Card or plastic blank, if present, from the PC Card slot.

2. Remove the hard drive.

3. Remove the keyboard

4. Remove the display assembly

5. Remove the palm rest

6. Remove the wireless network adapter

7. Remove the modem daughter card

8. Remove all installed memory modules

9. Remove the audio board

.

.

.

, if present.

, if present.

.

.

System Board Removal

1 fan
2 reserve battery cable
3 connector for fan extender cable
4 hard-drive connector
5 M2 x 4-mm screw (1)
6 memory module socket
7 guide pins (2)
8 5-mm hex nuts (4)
9 7-mm hex nuts (2)

10. Remove the four 5-mm hex nuts near each end of the serial and video connectors.

11. Use a flat-blade screwdriver to remove the two 7-mm hex nuts near each end of the docking connector.

12. Remove the two guide pins from the IDE connector.

13. Disconnect the cooling fan from the fan extender cable.

14. Disconnect the fan extender cable from the connector beside the internal memory socket.

15. Disconnect the reserve battery cable from the system board.

16. Remove the M2 x 4-mm screw that secures the right front corner of the system board.

17. Disengage the system board from the back panel.

Replacing the System Board

While replacing the system board, pull the fan extender cable aside to avoid trapping it beneath the system board. After
replacing the system board, route the cable between the hard-drive connector and the internal memory socket.

After you have replaced the system board, insert the floppy disk or CD that accompanied the replacement system board into
the appropriate drive, and turn on the computer. Follow the instructions on the screen.

NOTE: After replacing the system board, be sure to enter the computer's service tag sequence into the BIOS of the

replacement system board.

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Battery Latch

Dell™ Latitude™ C400 Service Manual

Removing the Battery Latch
Replacing the Battery Latch

Removing the Battery Latch

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 PC Card or plastic blank, if present, from the PC Card slot.

2. Remove the hard drive.

3. Remove the keyboard

4. Remove the display assembly

5. Remove the palm rest

6. Remove the wireless network adapter

7. Remove the modem daughter card

8. Remove all installed memory modules

9. Remove the audio board

10. Remove the system board

.

.

.

.

Battery Latch Removal

.

, if present.

, if present.

.

1 tension spring
2 bottom case
3 battery latch
4 battery release-button tabs

NOTICE: The tabs on the release button are plastic. When squeezing the tabs, be careful not to break them.

11. On the inside of the bottom case, use needle-nose pliers to gently squeeze the two release-button tabs together and
push the tabs down through the hole, catching the release button on the outside of the bottom case.

12. To remove the battery latch, unhook the small tension spring located on the metal post next to the hard drive.

Replacing the Battery Latch

1. With the inside of the bottom case facing up, place the battery latch in position.

2. Turn the bottom case over and align the slot in the battery latch with the release-button slot in the bottom case.

3. Holding the battery latch in place, press the release-button tabs through the underside of the bottom case and into the
battery latch until the tabs snap into place.

4. Replace the tension spring.

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Pin Assignments for I/O Connectors

Dell™ Latitude™ C400 Service Manual

Serial Connector USB Connector
Docking Connector IDE Module Bay Connector
Video Connector

Serial Connector

Pin Signal

1 DCD
2 RXDA
3 TXDA
4 DTR
5 GND
6 DSR
7 RTS
8 CTS
9 RI

Docking Connector

Pin Signal

Pin Signal

Pin Signal

Pin Signal

1 STRB#/5V
2 PD0
3 PD1
4 PD2
5 PD3
6 PD4
7 PD5

51 HSYNC
52 VSYNC
53 GND
54 DOCKED
55 USB_VD1+
56 USB_VD1­57 GND

101 VGA_GRN
102 GND
103 VGA_RED
104 GND
105 VGA_BLU
106 DOCK_SD/MODE
107 D_IRTX

151 GND
152 CLK_SPCI
153 GND
154 SAD0
155 SAD1
156 SAD2
157 SAD3

8 PD6

58 USB_VD2+

108 D_IRRX

158 SAD4
9 PD7
10 GND
11 DOCK_SPKR
12 DOCK_MIC
13 DOCK_LINE
14 DOCK_CDROM
15 GND
16 NC
17 POWER_SW#
18 QPCIEN#
19 S1.6M_EN#
20 DFDD/LPT#
21 GND
22 NC
23 NC
24 D_ACTLED
25 D_PWRLED

59 USB_VD2­60 DOCKOC1#
61 RUN_ON#
62 GND
63 NC
64 DOCK_SCLK
65 DOCK_LRCK
66 DOCK_MCLK
67 GND
68 +12V
69 AFD#
70 ERROR#
71 ACK#
72 GND
73 INIT#
74 SLCT_IN#
75 BUSY

109 GND
110 SPIRQB#
111 SPIRQC#
112 DAT_DDC2
113 CLK_DDC2
114 SPAR
115 SPME#
116 GND
117 SSERR#
118 SPERR#
119 SLOCK#
120 SSTOP#
121 GND
122 SDEVSEL#
123 STRDY#
124 SIRDY#
125 SFRAME#

159 SAD5

160 SAD6

161 GND

162 SAD7

163 SAD8

164 SC/BE0#

165 SAD9

166 SAD10

167 SAD11

168 SAD12

169 GND

170 SAD13

171 SAD14

172 SAD15

173 SAD16

174 SC/BE1#

175 CD/BE2#
26 DOCK_PWR_SRC
27 DOCK_PWR_SRC
28 DOCK_PWR_SRC
29 GND
30 +5VDOCK
31 +5VDOCK
32 +5VDOCK
33 +5VDOCK
34 +5VDOCK
35 GND
36 DOCK_PWR_SRC
37 DOCK_PWR_SRC
38 DOCK_PWR_SRC
39 DOCK_PWR_SRC
40 GND
41 DOCK_+DC_IN
42 DOCK_+DC_IN

76 PE
77 SLCT
78 GND
79 DAT_SMB
80 DCLK_SMB
81 SMB_INIT#
82 GND
83 DAT_DOCKSM1
84 CLK_DOCKSM1
85 DAT_DOCKKBD
86 CLK_DOCKKBD
87 GND
88 RI0
89 CTS0
90 RTS0
91 DSR0
92 GND

126 SCLKRUN#
127 GND
128 SGNTA#
129 SREQA#
130 SGNT0#
131 SREQ0#
132 SPCIRST#
133 SH1SEL#
134 GND
135 SWRPRT#
136 SDSKCHG#/DRQ
137 SDIR#
138 STRK0#
139 SSTEP#
140 SDRV1#
141 GND
142 SMTR1#

176 GND

177 SAD17

178 SAD18

179 SAD19

180 SAD20

181 SAD21

182 GND

183 SAD22

184 SAD23

185 SAD24

186 SC/BE3#

187 SAD25

188 GND

189 SAD26

190 SAD27

191 SAD28

192 SAD29
43 DOCK_+DC_IN
44 DOCK_+DC_IN
45 DOCK_+DC_IN
46 DOCK_+DC_IN
47 DOCK_+DC_IN

93 DTR0
94 TXD0#
95 RXD0#
96 DCD0
97 NC

143 SWRDATA#
144 SWGATE#
145 SRDATA#
146 SINDEX#
147 GND

193 SAD30

194 SAD31

195 GND

196 NC

197 NC

48 DOCK_+DC_IN

98 +5VSUS

148 NC

198 NC
49 GND
50 LOW_PWR

Video Connector

Pin Signal

1 RED
2 GREEN
3 BLUE
4 NC
5 GND

99 NC
100 NC

Pin Signal

9 CRT_VCC
10 GND
11 NC
12 DAT_DDC2
13 HSYNC

149 +5VALW
150 NC

199 NC

200 GND

6 GND
7 GND
8 GND

USB Connector

Pin Signal

1 VCC
2 –DATA
3 +DATA
4 GROUND

14 VSYNC
15 CLK_DDC2

IDE Module Bay Connector

Pin Signal

Pin Signal

1 BAY_MODPRES#
2 HDSEL#
3 RDATA#
4 WRPRT#
5 WRDATA#
6 INDEX#
7 DSKCHG#
8 1D6M_EN#
9 SIDE_IOW#
10 SIDED15
11 SIDED12
12 SIDED9
13 SIDE_CS3#
14 SIDE_CS1#
15 +5VMOD
16 IRQ15
17 +5VMOD

35 WGATE#
36 GND
37 MTR0#
38 STEP#
39 DRV0#
40 GND
41 DIR#
42 TRKO#
43 BAY_CD_FDD#
44 GND
45 SIDED1
46 SIDED4
47 SIDED7
48 GND
49 SIDEIORDY
50 GND

51 SIDE_DREQ
18 SIDED0
19 +5VMOD
20 SIDED3
21 +5VMOD
22 SIDED6
23 +5VMOD
24 SIDE_A2
25 +5VMOD
26 SIDE_DACK#
27 +5VMOD
28 SIDE_IOR#
29 +5VMOD
30 SIDED14
31 +5VMOD
32 SIDED11
33 +5VMOD
34 MOD_CD_R

52 GND

53 SIDED13

54 SIDED10

55 IDE_RST_MOD_5V#

56 GND

57 SIDEACT#

58 SIDE_A1

59 SIDE_A0

60 GND

61 SIDE_CSEL_SEC#

62 SIDED2

63 SIDED5

64 GND

65 SIDED8

66 MOD_CL_L

67 CDGND

68 BAY_MODPRES#

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