dell latitude c540 User Manual

							Speaker Assemblies: Dell Latitude C540/C640 Service Manual
1antenna cable 7antenna cable
2 speaker interface cable 8right speaker holder
3 in-line connector 9mounting ring
4 left speaker 10right speaker
5 mounting ring 11speaker interface cable
6 left speaker holder   
1.  Remove the 
hard drive. 
2.  Remove the 
keyboard. 
3.  Remove the 
display assembly. 
4.  Remove the 
palm rest. 
5.  Disconnect the speaker interface cables. (Do not attempt to disconnect \
the  antenna cables.) 
NOTICE: Do not pull the antenna wire when removing the speaker. 
NOTICE: Handle the speaker assemblies and speakers carefully to avoid 
damaging the speaker cones. 
6.  Remove the speaker assemblies by pulling them straight out of the bottom\
 case. 
7.  Remove the speakers from the holders by sliding the speakers out of the \
bottom  of the holders. 
NOTE: The left speaker has an in-line connector; the left antenna cable is lon\
ger 
than the right antenna cable. 
Replacing the Speaker Assemblies 
For each speaker:
1.  Slide the new speaker into its holder so that the speaker will face outw\
ard 
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							Speaker Assemblies: Dell Latitude C540/C640 Service Manual
(toward the speaker grill on the side of the computer) when the speake\
r 
assembly is installed. 
2.  Place the mounting ring over the front palm-rest screw post. 
3.  Slide the speaker assembly down into the bottom case. 
NOTICE: Ensure that the speaker wires are routed securely under their 
mounting clips. 
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							System Board: Dell Latitude C540/C640 Service Manual
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System Board 
Dell™ Latitude™ C540/C640 Service Manual
Removing the System Board 
The system boards BIOS chip contains the service tag sequence, which is\
 also visible 
on a bar code label on the bottom of the computer. The replacement kit f\
or the 
system board includes 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 
hard drive. 
2.  Remove the 
keyboard. 
3.  Remove the 
display assembly. 
4.  Remove the 
palm rest. 
5.  Remove the 
microprocessor thermal cooling assembly. 
6.  Remove the 
microprocessor module. 
7.  Remove the 
modem, memory modules, and Mini PCI card. 
8.  From the bottom of the computer, remove the six M2.5 x 5-mm screws label\
ed  circle B that secure the system board to the bottom case. 
9.  Remove the three M2.5 x 5-mm screws labeled circle B that secure the f\
an  guard to the bottom case. 
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							System Board: Dell Latitude C540/C640 Service Manual
 
1 fan guard
2 M2.5 x 5-mm screws (9)
10.  Turn the computer over and remove the M2.5 x 5-mm screw, which is labele\
d  circle B with an arrow on the front center of the system board by the \
battery 
connector. 
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							System Board: Dell Latitude C540/C640 Service Manual
 
1 M2.5 x. 5-mm screw (1)
2 audio connector 
locations; pull outward 
here
11.  Remove the 
speaker assemblies from the bottom case. 
12.  Pull the right side of the bottom case, next to the audio connectors, aw\
ay from  the system board as you simultaneously lift the front of the system boar\
d out 
and away from the bottom case. 
Replacing the System Board 
1.  Install the microprocessor module on the replacement system board. 
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							System Board: Dell Latitude C540/C640 Service Manual
2.  Install the replacement system board: a.  Insert the external microphone and headphone connectors through the bottom case. 
b.  Replace the six M2.5 x 5-mm screws, starting on the right side of the  bottom case. 
c.  Replace the fan guard, inserting the tab into the bottom case, and repla\
ce  the three M2.5 x 5-mm screws. Replacing the screw opposite the tab first\
 
makes it easier to insert and replace the other two screws. 
3.  Replace the modem and the microprocessor thermal cooling assembly that y\
ou  removed from the old system board. 
NOTE: Route cables so that they will not be crimped or pinched when the 
complete assembly is put back together. 
4.  Install the right and left 
speaker assemblies that came with the new system 
board in the bottom case. 
5.  Replace the palm rest, the keyboard, the display assembly, and the hard \
drive. 
6.  Replace the module bay devices and any PC Cards or plastic blanks in the\
 PC  Card slot. 
7.  Insert the flash BIOS update floppy disk or CD that accompanied the  replacement system board, and turn on the computer. Follow the instructi\
ons on 
the screen. 
NOTE: After replacing the system board, enter the computer service tag 
sequence into the BIOS of the replacement system board. 
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							Battery and Module Bay Latches: Dell Latitude C540/C640 Service Manual
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Battery and Module Bay Latches 
Dell™ Latitude™ C540/C640 Service Manual
Removing the Battery and Module Bay Latches 
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. 
5.  To remove the latch release button, use a plastic scribe to push inward \
on the  snap tabs in the upper latch assembly until the latch release button is \
released 
from the bottom case. 
To prevent the upper latch assembly from coming loose, apply pressure to\
 the 
latch and spring while removing the latch release button. 
6.  If you are also removing the upper latch assembly, lift it out of the la\
tch holding  fixture. 
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							Battery and Module Bay Latches: Dell Latitude C540/C640 Service Manual
 
1 bumps (2 per latch) 5latch release buttons (2)
2 slider 6snap tabs (2 per latch 
assembly)
3 spring 7upper latch assemblies (2)
4 bottom case 8wear rib
Replacing the Battery and Module Bay Latches 
1.  If you are replacing the upper latch assembly: 
a.  Slide the spring onto the slider, and install the upper latch assembly i\
n the holding feature on the inside of the bottom case. 
b.  Ensure that the slider is inserted into the hole, that the side of the l\
atch 
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							Battery and Module Bay Latches: Dell Latitude C540/C640 Service Manual
with the two bumps is facing the back of the case, and that the side wit\
h 
the wear rib is facing the front of the case. 
NOTE: The latch will not function properly if the slider is oriented incorrect\
ly. 
2.  Hold down the upper latch assembly and snap in the new latch release but\
ton  through the bottom case, ensuring that the snap tabs are fully engaged i\
n the 
upper latch assembly. 
3.  Ensure that the newly installed latch release button moves smoothly and \
freely  when pushed and released. 
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							Pin Assignments for I/O Connectors: Dell Latitude C540/C640 Service Manu\
al
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Pin Assignments for I/O Connectors 
Dell™ Latitude™ C540/640 Service Manual
USB Connector 
 
Pin Signal
1 VCC
2 –Data
3 +Data
4 Ground
Serial Connector 
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