dell latitude c840 User Manual

							Dell Latitude C840 Service Manual
Dell™ Latitude™ C840 Service Manual
Before You Begin
Preparing to Work Inside the Computer 
Recommended Tools 
Computer Orientation 
Screw Identification 
System Components
Hard Drive and Fixed Optical Drive
Hard Drive 
Fixed Optical Drive 
System Upgrades
Memory Modules 
Modem Daughter Card 
Mini PCI Card 
Keyboard
Display
Display Overview 
Hinge Cover 
Display Assembly 
Display Bezel 
Display Panel 
Display Latch 
Microprocessor Thermal-Cooling Assembly
Microprocessor Module
Video Graphics Board
Palm Rest
Reserve Battery
System Board
Battery and Module Bay Latches
Battery Charger Board
LED Board
Fan
RJ-11/RJ-45 Module
Pin Assignments for I/O Connectors
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							Before You Begin: Dell Latitude C840 Service Manual
Back to Contents Page 
Before You Begin 
Dell™ Latitude™ C840 Service Manual
  Preparing to Work Inside the Computer
  Recommended Tools
  Computer Orientation
  Screw Identification
Preparing to Work Inside the Computer
 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 warrantly. Read and follow all safety instruction\
s 
in Safety and EMC Instructions: Portable Computers in your System 
Information Guide.
NOTICE: To avoid damaging the computer, perform the following steps before 
you begin working inside the computer. 
1.  Ensure that the work surface is flat and 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. 
4.  Ensure that the computer is undocked. 
5.  Disconnect the computer from the electrical outlet. 
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							Before You Begin: Dell Latitude C840 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 surfa\
ce. 
10.  Remove the battery from the battery bay. 
NOTICE: To avoid component damage, always remove any installed batteries 
before you service the computer. 
11.  Remove any device installed in the module bay. 
12.  To dissipate static electricity while you work, periodically touch an un\
painted  metal surface on the computer chassis. 
13.  Handle components and cards by their edges, and avoid touching pins and \
 contacts. 
Recommended Tools
The procedures in this document require the following tools:
l     #1 magnetized Phillips screwdriver
l     Small flat-blade screwdriver
l     Microprocessor extractor
l     Nonmarring plastic scribe
l     Flash BIOS update floppy disk or CD (provided when needed to upgrade th\
e 
BIOS)
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							Before You Begin: Dell Latitude C840 Service Manual
Computer Orientation
 
Screw Identification
When you are removing and replacing components, photocopy the placemat a\
s a tool 
to lay out and keep track of the component screws. The placemat provides\
 the 
number of screws and the sizes.
Screw Identification 
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							Before You Begin: Dell Latitude C840 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 Security:
M3 x 5 mm (1 each)
  Keyboard to Bottom Case:
M2.5 x 20 mm (4 each; one in 
memory door and one in Mini 
PCI door)
 Display to Bottom 
Case:
M2.5 x 6 mm (3 
each; 2 at back of 
computer; 1 at 
display flex-cable 
strain relief)
 
Display Bezel:
Rubber screw covers (4 each)
Plastic screw covers (2 each)
M2.5 x 4 mm (6 each)
  Display Panel to Display 
Mounting Bracket:
M2 x 3 mm (6 each)
 
Flex-Cable Mounting Bracket to 
Top Cover:
Video Graphics 
Board:
M2.5 x 8 (3 each)
 
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							Before You Begin: Dell Latitude C840 Service Manual
M2.5 x 4 mm (1 each)
 
Palm Rest to
Bottom Case:
M2.5 x 20 mm (9 each)
 
Palm Rest Bracket:
M2.5 x 4 mm (4 each)
  System Board:
M2.5 x 4 mm captive washer 
(3 each)
 
M2.5 x 20 mm (1 each)
  LED Board:
M2 x 4 mm (2 each)
 
Fan:
M2 x 4 mm (3 each)
  Memory Module/Modem Cover:
M2.5 x 20 mm (1 each) 
Modem Daughter 
Card:
M2 x 3 mm (1 each)
 
Mini PCI Card:
M2.5 x 20 mm (1 each)
   
 
Back to Contents Page
 
 
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							Before You Begin: Dell Latitude C840 Service Manual
 
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							System Components: Dell Latitude C840 Service Manual
Back to Contents Page 
System Components 
Dell™ Latitude™ C840 Service Manual
NOTICE: Unless otherwise noted, each procedure in this document assumes 
that a part can be replaced by performing the removal procedure in rever\
se 
order. 
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							System Components: Dell Latitude C840 Service Manual
 
1 display assembly 7main battery
2 hinge cover 8device in module 
bay
3 microprocessor thermal-
cooling assembly 9
fixed optical drive
4 system board 10palm rest
5 hard drive 11keyboard
6 bottom case   
Back to Contents Page
 
 
 
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							Hard Drive and Fixed Optical Drive: Dell Latitude C840 Service Manual
Back to Contents Page 
Hard Drive and Fixed Optical Drive 
Dell™ Latitude™ C840 Service Manual
  Hard Drive
  Fixed Optical Drive 
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. 
Hard Drive
NOTICE: Disconnect the computer and attached devices from the electrical 
outlet and remove any installed batteries. 
NOTICE: To avoid ESD, ground yourself by using a wrist grounding strap or by 
periodically touching unpainted metal on the computer. 
NOTICE: The hard drive is very sensitive to shock. Handle the drive by its 
edges (do not squeeze the top of the case), and avoid dropping it. 
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