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 Grap
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.
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 surface. 10. Remove the battery from the battery bay.
Before You Begin: Dell Latitude C840 Service Manual Computer Orientation Screw Identification When you are removing and replacing components, photocopy the placemat as a tool to lay out and keep track of the component screws. The placemat provides the number of screws and the sizes. Screw Identification file:///F|/Service%20Manuals/Dell/Latitude/c840/begin.
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. Display to Bottom Case: Hard-Drive Door Security: Keyboard to Bottom Case: M3 x 5 mm (1 each) M2.
Before You Begin: Dell Latitude C840 Service Manual M2.5 x 4 mm (1 each) Palm Rest to Bottom Case: System Board: LED Board: M2.5 x 20 mm (9 each) M2.5 x 4 mm captive washer (3 each) M2 x 4 mm (2 each) Palm Rest Bracket: M2.5 x 4 mm (4 each) M2.5 x 20 mm (1 each) Fan: Memory Module/Modem Cover: M2 x 4 mm (3 each) M2.5 x 20 mm (1 each) Mini PCI Card: M2.5 x 20 mm (1 each) Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/begin.
Before You Begin: Dell Latitude C840 Service Manual file:///F|/Service%20Manuals/Dell/Latitude/c840/begin.
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 reverse order. file:///F|/Service%20Manuals/Dell/Latitude/c840/system.
System Components: Dell Latitude C840 Service Manual 1 display assembly 7 main battery 2 hinge cover 8 device in module bay 3 microprocessor thermalcooling assembly 9 fixed optical drive 4 system board 10 palm rest 5 hard drive 11 keyboard 6 bottom case Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/system.
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.
Hard Drive and Fixed Optical Drive: Dell Latitude C840 Service Manual 1 bottom of computer 2 M3 x 5-mm screw 3 hard drive door Removing the Hard Drive 1. Follow the instructions in "Preparing to Work Inside the Computer." 2. Remove the M3 x 5-mm screw. 3. Pull the hard drive out. Replacing the Hard Drive 1. Push the hard drive into the drive bay until the drive door is flush with the computer case. file:///F|/Service%20Manuals/Dell/Latitude/c840/hdd.
Hard Drive and Fixed Optical Drive: Dell Latitude C840 Service Manual 2. Push down on the drive until it snaps into place. 3. Replace the M3 x 5-mm screw in the hard drive door. Fixed Optical 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.
Hard Drive and Fixed Optical Drive: Dell Latitude C840 Service Manual Removing the Fixed Optical Drive 1. Follow the instructions in "Preparing to Work Inside the Computer." 2. Loosen the captive screw on the bottom of the computer. 3. Turn the computer over (to keep the captive screw from interfering with the pull tab) and pull out the pull tab. 4. Use the pull tab to remove the fixed optical drive. Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/hdd.
System Upgrades: Dell Latitude C840 Service Manual Back to Contents Page System Upgrades Dell™ Latitude™ C840 Service Manual Memory Modules Modem Daughter Card Mini PCI Card 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 periodically touching unpainted metal on the computer.
System Upgrades: Dell Latitude C840 Service Manual 1 M2.5 x 20-mm screw 1. Follow the instructions in "Preparing to Work Inside the Computer." 2. Remove the M2.5 x 20-mm screw from the memory module/modem cover. 3. Disengage the metal tabs at the opposite end of the cover. file:///F|/Service%20Manuals/Dell/Latitude/c840/upgrades.
System Upgrades: Dell Latitude C840 Service Manual 1 DIMM B 2 memory module sockets (2) 3 DIMM A socket 4 modem daughter card 5 metal tabs (2 per socket) Removing the Memory Modules 1. Remove the memory module/modem cover. 2. To release a memory module from its socket, spread apart the tabs at each side of the module until the module pops up slightly. 3. Lift the memory module out of its socket. file:///F|/Service%20Manuals/Dell/Latitude/c840/upgrades.
System Upgrades: Dell Latitude C840 Service Manual Replacing the Memory Modules 1. If you only have one memory module, install it in the socket labeled "DIMM A." Install a second memory module in the socket labeled "DIMM B." NOTE: Memory modules are keyed to fit into their sockets in only one direction. 2. Insert the memory-module edge connector into the socket slot at a 45-degree angle and press the module firmly into the slot. 3. Pivot the module down until it clicks into place.
System Upgrades: Dell Latitude C840 Service Manual 1 modem daughter card 2 M2 x 3-mm screw 3. Remove the M2 x 3-mm screw that secures the modem daughter card to the system board. 4. Use the pull tab to pull the modem daughter card straight up out of its connector. NOTICE: Do not pull on the modem cable. Pull the connector on the end of the cable to disconnect the cable. 5. Disconnect the modem cable from the modem daughter card.
System Upgrades: Dell Latitude C840 Service Manual 2. Use the screw and boss holes at opposite corners of the modem daughter card to align the card, and press the card into its connector on the system board. 3. Install the M2 x 3-mm screw that secures the card to the system board. 4. Replace the memory module/modem cover. Mini PCI Card You must remove the optional Mini PCI wireless modem (if installed) before the system board can be removed.
System Upgrades: Dell Latitude C840 Service Manual 1 M2.5 x 20-mm screw Removing the Mini PCI Card 1. Follow the instructions in "Preparing to Work Inside the Computer." 2. Remove the M2.5 x 20-mm screw and then remove the Mini PCI card cover. 3. To release the Mini PCI card, spread the metal securing tabs until the card pops up slightly. 4. Disconnect the card from the internal antenna. 5. Lift out the card and disconnect any attached cables. Replacing the Mini PCI Card 1.
System Upgrades: Dell Latitude C840 Service Manual 2. Connect the internal-antenna cable to the primary-antenna connector on the card. NOTICE: The connectors are keyed for correct insertion; do not force the connections. 1 internal-antenna cable 2 primary-antenna connector on card 3. Pivot the Mini PCI card down until it clicks into place. 4. Replace the Mini PCI card cover and the M2.5 x 20-mm screw. file:///F|/Service%20Manuals/Dell/Latitude/c840/upgrades.
System Upgrades: Dell Latitude C840 Service Manual Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/upgrades.
Keyboard: Dell Latitude C840 Service Manual Back to Contents Page Keyboard Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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. file:///F|/Service%20Manuals/Dell/Latitude/c840/keyboard.
Keyboard: Dell Latitude C840 Service Manual 1 M2.5 x 20-mm screws (4) Removing the Keyboard 1. Follow the instructions in "Preparing to Work Inside the Computer." 2. Turn the computer over and remove the four M2.5 x 20-mm screws (three labeled "circle K" and one labeled "circle K/M"). 3. Turn the computer over and open the display. NOTICE: Be careful when handling the keyboard. The keycaps are fragile, easily dislodged, and time-consuming to replace. 4.
Keyboard: Dell Latitude C840 Service Manual 1 blank key 2 keyboard 3 right side of computer 5. Lift the right end of the keyboard and slide it slightly toward the right side of the computer to disengage the tabs at the left end. 6. Pivot the keyboard and balance it upright on the left side of the computer. file:///F|/Service%20Manuals/Dell/Latitude/c840/keyboard.
Keyboard: Dell Latitude C840 Service Manual 1 keyboard cable 2 keyboard interface connector 3 system board 7. Disconnect the keyboard cable and lay the keyboard aside. Replacing the Keyboard 1. While bracing the keyboard upright on its left end, connect the keyboard cable to the keyboard interface connector on the system board. file:///F|/Service%20Manuals/Dell/Latitude/c840/keyboard.
Keyboard: Dell Latitude C840 Service Manual NOTICE: Position the keyboard/track-stick flex cable so that it is not pinched when you replace the keyboard in the bottom case. 2. Insert the metal tabs at the left end of the keyboard under the edge of the bottom case, and fit the keyboard into place. 3. Check that the keyboard is correctly installed. The keys should be flush with the left and right surfaces of the palm rest. 4. Turn the computer over and reinstall the four M2.5 x 20-mm screws.
Display: Dell Latitude C840 Service Manual Back to Contents Page Display Dell™ Latitude™ C840 Service Manual Display Overview Hinge Cover Display Assembly Display Bezel Display Panel Display Latch Display Overview NOTICE: Disconnect the computer and attached devices from electrical outlets 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.
Display: Dell Latitude C840 Service Manual 1 display 2 hinge cover 3 M2.5 x 6-mm screws (3) 4 bottom case 5 display flex cable file:///F|/Service%20Manuals/Dell/Latitude/c840/display.
Display: Dell Latitude C840 Service Manual Hinge Cover 1 hinge cover 1. Follow the instructions in "Preparing to Work Inside the Computer." 2. Use a nonmarring plastic scribe to loosen the hinge cover at the back and at each side of the computer. 3. Open the computer and use the scribe to pry between the hinge cover until the hinge cover pops off. 4. Open the display and lift off the hinge cover. Display Assembly file:///F|/Service%20Manuals/Dell/Latitude/c840/display.
Display: Dell Latitude C840 Service Manual 1 M2.5 x 6-mm screws (2) 1. Remove the hinge cover. NOTICE: Remove the display flex cable before you remove the display assembly. file:///F|/Service%20Manuals/Dell/Latitude/c840/display.
Display: Dell Latitude C840 Service Manual 1 M2.5 x 6-mm screw 2 strain relief 3 display flex cable 4 pull loop 2. Remove the M2.5 x 6-mm flex-cable strain relief screw, and then use the pull loop to remove the display flex cable from the graphics card. NOTICE: When reconnecting the flex cable, press down on both ends of the connector, not in the middle. Pressing the middle of the connector can damage fragile components. 3. Open the display and, from the back of the computer, remove the two M2.
Display: Dell Latitude C840 Service Manual file:///F|/Service%20Manuals/Dell/Latitude/c840/display.
Display: Dell Latitude C840 Service Manual 1 M2.5 x 4-mm screws (6) 8 M2 x 3-mm screws (6) 2 rubber screw covers (4) 9 top cover 3 display bezel 10 hinge cover 4 plastic tabs (6) 11 display flex cable 5 M2.5 x 4-mm screw 12 display panel 6 flex-cable mounting bracket 13 plastic screw covers (2) 7 display latch Display Bezel 1. Use a scribe to pry out the four rubber screw covers located across the top of the bezel. 2. Remove the four M2.5 x 4-mm screws located across the top of the bezel. 3.
Display: Dell Latitude C840 Service Manual 2. Detach the display flex cable from the strain relief and the graphics card. 3. Remove the display bezel. 4. Remove the M2.5 x 4-mm screw that secures the plastic flex-cable mounting bracket to the top cover. 5. Remove the six M2 x 3-mm screws (three on each side) from the right and left sides of the panel. 6. Lift the display panel and flex cable out of the top cover. 7.
Display: Dell Latitude C840 Service Manual 1 ZIF connector 2 standard connector Replacing the Display Panel NOTE: Use a magnetic screwdriver to reassemble the display panel in the display. 1. Connect the flex cable to the two connectors on the back of the display panel. 2. Place the display panel in the top cover, taking care that the flex cable is in place and is not crushed or crimped. 3. Reinstall the M2.5 x 4-mm screw that secures the flex-cable mounting bracket to the top cover. 4.
Display: Dell Latitude C840 Service Manual 1. Remove the hinge cover. 2. Detach the display flex cable from the strain relief and the graphics card. 3. Remove the display bezel. 4. Remove the display panel from the top cover. 5. Remove the display latch by disengaging the latch and captive spring. Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/display.
Microprocessor Thermal-Cooling Assembly: Dell Latitude C840 Service Manual Back to Contents Page Microprocessor Thermal-Cooling Assembly Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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.
Microprocessor Thermal-Cooling Assembly: Dell Latitude C840 Service Manual 2 microprocessor retaining clip Removing the Microprocessor Thermal-Cooling Assembly 1. Follow the instructions in "Preparing to Work Inside the Computer." 2. Remove the keyboard. 3. Remove the hinge cover. 4. Insert a non-marring plastic scribe into the latch mechanism at the left side of the microprocessor retaining clip. Pry open the clip by pivoting the top of the screwdriver toward the right side of the computer.
Microprocessor Thermal-Cooling Assembly: Dell Latitude C840 Service Manual NOTICE: To ensure maximum cooling for the microprocessor, do not touch the heat transfer areas on the microprocessor thermal-cooling assembly. The oils in your skin reduce the heat transfer capability of the thermal pads. 5. Lift out the thermal-cooling assembly. Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/thermal.
Microprocessor Module: Dell Latitude C840 Service Manual Back to Contents Page Microprocessor Module Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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. Removing the Microprocessor Module 1. Follow the instructions in "Preparing to Work Inside the Computer." 2.
Microprocessor Module: Dell Latitude C840 Service Manual NOTICE: To ensure maximum cooling for the microprocessor, do not touch the heat transfer areas on the microprocessor thermal-cooling assembly. The oils in your skin reduce the heat transfer capability of the thermal pads. 4. Remove the microprocessor thermal-cooling assembly. NOTICE: When removing the microprocessor module, pull the module straight up. Do not bend the pins. 5. Remove the microprocessor module.
Microprocessor Module: Dell Latitude C840 Service Manual 1 cam screw 2 perpendicular screwdriver 3 processor die (do not touch) b. Use the microprocessor extraction tool to remove the microprocessor module. Replacing the Microprocessor Module NOTICE: If you received a flash BIOS update floppy disk or CD with the replacement microprocessor, you must update the BIOS after replacing the microprocessor module. NOTICE: Proper seating of the microprocessor module does not require force.
Microprocessor Module: Dell Latitude C840 Service Manual 1. Align the pin-1 triangle on the microprocessor with the pin-1 triangle in the socket, insert the microprocessor into the socket, and move the microprocessor around slightly until you feel it settle into the socket. When the microprocessor module is correctly seated, all four corners are aligned to the same height. If one or more corners of the module are higher than the others, the module is not seated correctly.
Microprocessor Module: Dell Latitude C840 Service Manual 4. Close the microprocessor retaining clip. 5. To latch the clip, insert a flat-blade scribe into the latch mechanism and pivot the top of the scribe away from the clip. Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/cpu.
Video Graphics Board: Dell Latitude C840 Service Manual Back to Contents Page Video Graphics Board Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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. 1 M2.5 x 8-mm screws (3) Removing the Video Graphics Board 1.
Video Graphics Board: Dell Latitude C840 Service Manual 3. Remove the hinge cover. NOTICE: The video graphics board may have a metallic or cardboard-like EMI shield attached to the top. If present, the EMI shield is removed with the board. Do not reuse the EMI shield on the replacement video board. Newer versions of the board may not require the shield; if a shield is required, it is already attached to the replacement board. 4. Detach the display flex cable from the graphics card. 5. Remove the three M2.
Palm Rest: Dell Latitude C840 Service Manual Back to Contents Page Palm Rest Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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. 1 pull loop file:///F|/Service%20Manuals/Dell/Latitude/c840/palmrest.
Palm Rest: Dell Latitude C840 Service Manual NOTICE: The reserve battery provides power to the computer's time RTC and NVRAM when the computer is turned off. Removing the palm rest disconnects the reserve battery and causes the computer to lose the date and time information as well as all user-specified parameters in NVRAM. If possible, copy the information before you disconnect the reserve battery. Removing the Palm Rest 1. Follow the instructions in "Preparing to Work Inside the Computer." 2.
Palm Rest: Dell Latitude C840 Service Manual 1 M2.5 x 20-mm screws (9) 8. Turn the computer over. 9. Use the pull loop to disconnect the palm-rest flex cable from the touch-pad connector on the system board. 10. On the left and right sides of the palm rest, use a flat-blade scribe between the palm rest and the bottom case of the computer to separate the snaps that secure the palm rest to the bottom case. 11. Lift out the palm rest. file:///F|/Service%20Manuals/Dell/Latitude/c840/palmrest.
Palm Rest: Dell Latitude C840 Service Manual Replacing the Palm Rest When replacing the palm rest screws, install the two screws at the back corners of the computer first to help align the palm rest correctly. Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/palmrest.
Reserve Battery: Dell Latitude C840 Service Manual Back to Contents Page Reserve Battery Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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. 1 palm rest bracket 2 reserve battery 3 reserve battery cable file:///F|/Service%20Manuals/Dell/Latitude/c840/resbatt.
Reserve Battery: Dell Latitude C840 Service Manual 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 NVRAM. If possible, copy the information before you remove the reserve battery. Removing the Reserve Battery 1. Follow the instructions in "Preparing to Work Inside the Computer." 2. Remove the keyboard. 3.
Reserve Battery: Dell Latitude C840 Service Manual 1 M2.5 x 4-mm screws (4) 2 palm rest bracket 3 palm-rest flex cable 7. Remove the four M2.5 x 4-mm screws that secure the palm rest bracket. 8. While supporting the palm-rest flex cable, lift out the palm rest bracket and turn it over. 9. Disconnect the reserve battery cable. 10. Remove the reserve battery: a. Pry the reserve battery free from the metal palm rest bracket. b. Remove the foam-pad remnants from the palm rest bracket.
System Board: Dell Latitude C840 Service Manual Back to Contents Page System Board Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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. 1 M2.5 x 4-mm captivewasher screws (3) file:///F|/Service%20Manuals/Dell/Latitude/c840/sysboard.
System Board: Dell Latitude C840 Service Manual 2 system board 3 network connector 4 modem connector 5 network cable cover 6 M2.5 x 20-mm screw The BIOS chip on the system board contains the service tag sequence, which is also visible on a bar code label on the bottom of the computer. The replacement kit for the system board includes a floppy disk or CD that provides a utility for transferring the service tag sequence to the replacement system board.
System Board: Dell Latitude C840 Service Manual 12. If migrating the microprocessor, remove the microprocessor module. 13. Separate the network cable from the system board: a. First remove the network cable cover: Insert a narrow plastic scribe or small screwdriver just barely into the slot that faces the back of the computer (do not insert the scribe far enough to catch on the wires inside), press down on the cover lightly to secure it, and pry upward to release the cover. 1 network cable cover b.
System Board: Dell Latitude C840 Service Manual 1 outer corner of upper connector 2 network cable 14. Remove the three M2.5 x 4-mm captive-washer screws from the system board. 15. Remove the M2.5 x 20-mm screw from the center of the LED board. 16. Lift the front of the system board and work it out of the back panel. If necessary to help release the system board, pull outward on the top of the plastic near the back left corner of the bottom case (see the small arrow at the far left in the following figure).
System Board: Dell Latitude C840 Service Manual Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/sysboard.
Battery and Module Bay Latches: Dell Latitude C840 Service Manual Back to Contents Page Battery and Module Bay Latches Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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. file:///F|/Service%20Manuals/Dell/Latitude/c840/baylatch.
Battery and Module Bay Latches: Dell Latitude C840 Service Manual 1 wear ribs (2 on underside) 2 bumps 3 slider 4 spring 5 bottom case 6 latch housing (2) 7 latch buttons (2) 8 location of snap tabs (2) Removing and Replacing the Battery and Module Bay Latches 1. Follow the instructions in "Preparing to Work Inside the Computer." 2. Remove the keyboard. 3. Remove the hinge cover. 4. Remove the display assembly. 5. Remove the palm rest. 6.
Battery and Module Bay Latches: Dell Latitude C840 Service Manual b. Ensure that the slider is inserted so that the side with the two bumps is facing the back of the bottom case, and the surface with the wear ribs lies against the upper surface of the bottom case. 7. Hold the upper latch assembly in place while you snap the new latch button in from underneath the bottom case, making certain the snap tabs are fully engaged in the slider.
Battery Charger Board: Dell Latitude C840 Service Manual Back to Contents Page Battery Charger Board Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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. Removing the Battery Charger Board 1. Follow the instructions in "Preparing to Work Inside the Computer." 2.
Battery Charger Board: Dell Latitude C840 Service Manual 4. Remove the display assembly. 5. Remove the palm rest. 6. Remove the video graphics board. 7. Lift the battery charger board out of the system board connector. Replacing the Battery Charger Board Align the screw holes on the battery charger board with the screw holes on the bottom case, and then press the battery charger board down into its connector. Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/battch.
LED Board: Dell Latitude C840 Service Manual Back to Contents Page LED Board Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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. 1 M2 x 4-mm screws (2) file:///F|/Service%20Manuals/Dell/Latitude/c840/led.
LED Board: Dell Latitude C840 Service Manual Removing the LED Board 1. Follow the instructions in "Preparing to Work Inside the Computer." 2. Remove the hinge cover. 3. Remove the two M2 x 4-mm screws. 4. Lift the LED board away from its connector. Replacing the LED Board 1. Align the two screw holes with the two mounting holes on the bottom case, and press the board into its connector. 2. Replace the two M2 x 4-mm screws. Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/led.
Fan: Dell Latitude C840 Service Manual Back to Contents Page Fan Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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. 1 fan cables 2 M2 x 4-mm screws (3) Removing the Fan 1. Follow the instructions in "Preparing to Work Inside the Computer.
Fan: Dell Latitude C840 Service Manual 2. Remove the system board. 3. Remove the three M2 x 4-mm screws from the fan. 4. Disconnect the two fan cables from the system board. 5. Pull the fan away from the back-panel bracket. NOTICE: When reconnecting the fan cables, connect the shorter cable to the connector closest to the fan. Route both cables so that they will not be pinched by the microprocessor thermal-cooling assembly. Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/fan.
RJ-11/RJ-45 Module: Dell Latitude C840 Service Manual Back to Contents Page RJ-11/RJ-45 Module Dell™ Latitude™ C840 Service Manual NOTICE: Disconnect the computer and attached devices from electrical outlets 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. 1 network cable 2 bottom case 3 RJ-11/RJ-45 module 4 modem cable file:///F|/Service%20Manuals/Dell/Latitude/c840/rj11_45b.
RJ-11/RJ-45 Module: Dell Latitude C840 Service Manual Removing the RJ-11/RJ-45 Module 1. Follow the instructions in "Preparing to Work Inside the Computer." 2. Remove the system board. 3. From outside the bottom case, push in and up on the RJ-11/RJ-45 module while pulling the side of the bottom case slightly outward. When the module disengages, lift it out. Replacing the RJ-11/RJ-45 Module When replacing the RJ-11/RJ-45 module, hold both cables safely out of the way and snap the housing down into place.
RJ-11/RJ-45 Module: Dell Latitude C840 Service Manual 1 vertical slot 2 modem cable When replacing the system board, ensure that the network cable is safely above the board and out of the way. Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/rj11_45b.
Pin Assignments for I/O Connectors: Dell Latitude C840 Service Manual Back to Contents Page Pin Assignments for I/O Connectors Dell™ Latitude™ C840 Service Manual USB Connector Pin Signal 1 VCC 2 -Data 3 +Data 4 Ground Serial Connector file:///F|/Service%20Manuals/Dell/Latitude/c840/pinouts.
Pin Assignments for I/O Connectors: Dell Latitude C840 Service Manual Pin Signal Pin Signal 1 DCD 6 DSR 2 RXDA 7 RTS 3 TXDA 8 CTS 4 DTR 9 RI 5 GND Parallel Connector Pin Signal Pin Signal file:///F|/Service%20Manuals/Dell/Latitude/c840/pinouts.
Pin Assignments for I/O Connectors: Dell Latitude C840 Service Manual 1 STRB# 11 BUSY 2 PD0 12 PE 3 PD1 13 SLCT 4 PD2 14 AFDF# 5 PD3 15 ERROR# 6 PD4 16 INIT# 7 PD5F 17 SLCT_IN 8 PD6F 18-23 GND 9 PD7F 24 DFDD/LPT# 10 ACK# 25 GND Video Connector Pin Signal Pin Signal 1 RED 9 CRT_VCC 2 GREEN 10 GND 3 BLUE 11 MSEN# 4 NC 12 DAT_DDC2 5 GND 13 HSYNC file:///F|/Service%20Manuals/Dell/Latitude/c840/pinouts.
Pin Assignments for I/O Connectors: Dell Latitude C840 Service Manual 6 GND 14 VSYNC 7 GND 15 CLK_DDC2 8 GND PS/2 Connector Pin Signal 1 DAT_KBD 2 DAT_SM1 3 GND 4 PS2VCC 5 CLK_KBD 6 CLK_SM1 S-Video TV-Out Connector file:///F|/Service%20Manuals/Dell/Latitude/c840/pinouts.
Pin Assignments for I/O Connectors: Dell Latitude C840 Service Manual S-Video Pin Signal 1 GND 2 GND 3 DLUMA-L 4 DCRMA-L Composite Video Pin Signal 5 SPDIF 6 DCMPS-L 7 SPGND Docking Connector file:///F|/Service%20Manuals/Dell/Latitude/c840/pinouts.
Pin Assignments for I/O Connectors: Dell Latitude C840 Service Manual Pin Signal Pin Signal 1 STRB#/5V 101 VGA_GRN 2 PD0 102 GND 3 PD1 103 VGA_RED 4 PD2 104 GND 5 PD3 105 VGA_BLU 6 PD4 106 DOCK_SD/MODE 7 PD5 107 D_IRTX 8 PD6 108 D_IRRX 9 PD7 109 GND 10 GND 110 SPIRQB# 11 DOCK_SPKR 111 SPIRQC# 12 DOCK_MIC 112 DAT_DDC2 13 DOCK_LINE 113 CLK_DDC2 14 DOCK_CDROM 114 SPAR 15 GND 115 SPME# 16 M_SEN# 116 GND 17 POWER_SW# 117 SSERR# file:///F|/S
Pin Assignments for I/O Connectors: Dell Latitude C840 Service Manual 18 QPCIEN# 118 SPERR# 19 S1.
Pin Assignments for I/O Connectors: Dell Latitude C840 Service Manual 45 DOCK_+DC_IN 145 SRDATA# 46 DOCK_+DC_IN 146 SINDEX# 47 DOCK_+DC_IN 147 GND 48 DOCK_+DC_IN 148 NC 49 GND 149 +5VALW 50 LOW_PWR 150 NC 51 HSYNC 151 GND 52 VSYNC 152 CLK_SPCI 53 GND 153 GND 54 DOCKED 154 SAD0 55 USB_VD1+ 155 SAD1 56 USB_VD1- 156 SAD2 57 GND 157 SAD3 58 USB_VD2+ 158 SAD4 59 USB_VD2- 159 SAD5 60 DOCKOCI# 160 SAD6 61 RUN_ON# 161 GND 62 GND 162 SAD7 63 N
Pin Assignments for I/O Connectors: Dell Latitude C840 Service Manual 72 GND 172 SAD15 73 INIT# 173 SAD16 74 SLCT_IN# 174 SC/BE1# 75 BUSY 175 CD/BE2# 76 PE 176 GND 77 SLCT 177 SAD17 78 GND 178 SAD18 79 DAT_SMB 179 SAD19 80 DCLK_SMB 180 SAD20 81 SMB_INIT# 181 SAD21 82 GND 182 GND 83 DAT_DOCKSM1 183 SAD22 84 CLK_DOCKSM1 184 SAD23 85 DAT_DOCKKBD 185 SAD24 86 CLK_DOCKKBD 186 SC/BE3# 87 GND 187 SAD25 88 RI0 188 GND 89 CTS0 189 SAD26 90 RTS
Pin Assignments for I/O Connectors: Dell Latitude C840 Service Manual 99 NC 199 NC 100 NC 200 GND IEEE 1394 Connector Pin Signal 1 TPB- 2 TPB+ 3 TPA- 4 TPA+ Back to Contents Page file:///F|/Service%20Manuals/Dell/Latitude/c840/pinouts.
