Dell Latitude C640 User Manual Page 1

Dell™ Latitude™ C540/C640 Service ManualBefore You BeginSystem ComponentsHard DriveMemory Modules, Mini PCI Card, and ModemKeyboardDisplay Assembly, D

Back to Contents PageMemory Modules, Mini PCI Card, and ModemDell™ Latitude™ C540/C640 Service Manual Memory Modules Mini PCI Card ModemMemory Modu

NOTICE: Disconnect the computer and any attached devices from electrical outlets, and remove any installedbatteries.NOTICE: To avoid ESD, ground yours

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

1 antenna connectors on card(2)2 antenna cables (2)Replacing the Mini PCI Card1. Align the Mini PCI card with the socket at a 45-degree angle, and pr

NOTICE: Do not pull on the modem cable. Pull from the modem connector to disconnect the cable.3. Pull straight up on the attached pull-tab to lift th

Back to Contents PageKeyboardDell™ Latitude™ C540/C640 Service ManualRemoving the KeyboardNOTICE: Disconnect the computer and any attached devices fro

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

1 boss supports (5)2 track stick cable3 keyboard flex cable4 keyboard interfaceconnector5 orientation label8. Remove the keyboard from the bottom cas

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Back to Contents PageDisplay Assembly, Display Latch, and Hinge CoversDell™ Latitude™ C540/C640 Service Manual Display Assembly Display Latch Hinge

Back to Contents PageBefore You BeginDell™ Latitude™ C540/C640 Service Manual Preparing to Work Inside the Computer Recommended Tools Screw Identif

1 M2 x 3-mm screws (2)2 top cover3 center control cover4 M2.5 x 5-mm screws (5)5 bottom case6 display-feed flex cable7 EMI shield bracket8. Remove th

1 M2 x 3-mm screws (2)2 pull-tab3 display-feed cableconnector4 interface connector9. Pull up on the pull-tab that is attached to the display-feed fle

1 rubber screw covers (6) 5 M2 x 4-mm screws (5)2 M2.5 x 5-mm screws (6) 6 display-feed flex cable3 display bezel 7 flex-cable retention bracket4 top

2. Remove the display assembly. 3. Use a plastic scribe to pry the six rubber screw covers out of the screw holes located on the front of the bezel.

1 display panel connector2 top flex cable connector3 pull-tab4 bottom flex cable connector5 inverter connector9. Remove the tape that secures the dis

NOTICE: Disconnect the computer and any attached devices from electrical outlets, and remove any installedbatteries.NOTICE: To avoid ESD, ground yours

Hinge CoversRemoving the Hinge Covers1. Remove the display assembly. 2. Rotate the hinges forward at an angle of approximately 90 degrees to the fro

1 right hinge cover2 left hinge coverBack to Contents Page

Back to Contents PagePalm RestDell™ Latitude™ C540/C640 Service ManualRemoving the Palm RestNOTICE: Disconnect the computer and any attached devices f

6. Turn the computer over, and remove the three M2 x 3-mm screws that secure the palm rest to the bottom case: a. Remove the two M2 x 3-mm screws th

Recommended ToolsThe procedures in this manual require the following tools:#1 magnetized Phillips screwdriver¼-inch flat-blade screwdriverSmall plasti

Back to Contents PageMicroprocessor Thermal Cooling AssemblyDell™ Latitude™ C540/C640 Service ManualRemoving the Microprocessor Thermal Cooling Assemb

pry the assembly up and out of the system board. Replacing the Microprocessor Thermal Cooling AssemblyNOTICE: To ensure proper thermal operation, alwa

Back to Contents PageMicroprocessor ModuleDell™ Latitude™ C540/C640 Service ManualRemoving the Microprocessor ModuleNOTICE: Disconnect the computer an

NOTICE: To ensure maximum cooling for the microprocessor, do not touch the heat transfer areas on themicroprocessor thermal cooling assembly. The oils

Back to Contents PageHybrid Cooling FanDell™ Latitude™ C540/C640 Service ManualRemoving the Hybrid Cooling FanNOTICE: Disconnect the computer and any

7. Disconnect the fan power cable from the system-board interface connector and remove the hybrid cooling fan. NOTE: The fan power cable is long, and

Back to Contents PageReserve BatteryDell™ Latitude™ C540/C640 Service ManualRemoving the Reserve BatteryNOTICE: The reserve battery provides power to

2 reserve battery tray3 reserve battery cable4 reserve battery connectoron system board5 speaker cables6 opening for reserve batterycableReplacing the

Back to Contents PageFlashing the BIOSDell™ Latitude™ C540/C640 Service ManualTo update the basic input/output system (BIOS):1. Ensure that the AC ad

Back to Contents PageSpeaker AssembliesDell™ Latitude™ C540/C640 Service ManualRemoving the Speaker AssembliesNOTICE: Disconnect the computer and any

NOTICE: When reinstalling a screw, you must use a screw of the correct diameter and length. Ensure that the screw isproperly aligned with its correspo

1 right speaker2 palm-rest screw posts (2)3 bottom case holders (2)4 left speaker

1 antenna cable 7 antenna cable2 speaker interface cable 8 right speaker holder3 in-line connector 9 mounting ring4 left speaker 10 right speaker5 mou

5. Disconnect the speaker interface cables. (Do not attempt to disconnect the antenna cables.) NOTICE: Do not pull the antenna wire when removing the

Back to Contents PageSystem BoardDell™ Latitude™ C540/C640 Service ManualRemoving the System BoardThe system board's BIOS chip contains the servi

1 fan guard2 M2.5 x 5-mm screws (9)10. Turn the computer over and remove the M2.5 x 5-mm screw, which is labeled "circle B" with an arrow o

11. Remove the speaker assemblies from the bottom case. 12. Pull the right side of the bottom case, next to the audio connectors, away from the syst

Back to Contents PageBattery and Module Bay LatchesDell™ Latitude™ C540/C640 Service ManualRemoving the Battery and Module Bay LatchesNOTICE: Disconne

1 bumps (2 per latch) 5 latch release buttons (2)2 slider 6 snap tabs (2 per latch assembly)3 spring 7 upper latch assemblies (2)4 bottom case 8 wear

Back to Contents PagePin Assignments for I/O ConnectorsDell™ Latitude™ C540/640 Service ManualUSB ConnectorPin Signal1 VCC2 –Data3 +Data4 GroundSerial

Pin Signal Pin Signal1 STRB#/5V 11 BUSY/MTR#2 PD0/INDEX# 12 PE/WDATA#3 PD1/TRK0# 13 SLCT/WGATE#4 PD2/WP# 14 AFDF#5 PD3/RDATA# 15 ERROR#HDSEL#6 PD4/DSK

Display Latch:(2 each) (2 each)Palm Rest toBottom Case:(3 each) (5 each)Hybrid Cooling Fan:(2 each) (1 each)System Board to BottomCase:(10 each)Back t

PS/2 ConnectorPin Signal1 DAT_KBD2 DAT_SM13 GND4 PS2VCC5 CLK_KBD6 CLK_SM1S-Video TV-Out ConnectorS-VideoPin Signal1 GND2 GND3 DLUMA-L4 DCRMA-LComposit

5 NC6 DCMPS-L7 GNDDocking ConnectorPin Signal Pin Signal1 STRB#/5V 101 VGA_GRN2 PD0 102 GND3 PD1 103 VGA_RED4 PD2 104 GND5 PD3 105 VGA_BLU6 PD4 106 DO

26 DOCK_PWR_SRC 126 SCLKRUN#27 DOCK_PWR_SRC 127 GND28 DOCK_PWR_SRC 128 SGNTA#29 GND 129 SREQA#30 +5VDOCK 130 SGNT0#31 +5VDOCK 131 SREQ0#32 +5VDOCK 132

66 DOCK_MCLK 166 SAD1067 GND 167 SAD1168 +12V 168 SAD1269 AFD# 169 GND70 ERROR# 170 SAD1371 ACK# 171 SAD1472 GND 172 SAD1573 INIT# 173 SAD1674 SLCT_IN

Back to Contents PageSystem ComponentsDell™ Latitude™ C540/C640 Service ManualNOTICE: Only a certified service technician should perform repairs on yo

9 fan guard Back to Contents Page

Back to Contents PageHard DriveDell™ Latitude™ C540/C640 Service ManualRemoving the Hard Drive1. Save and close any open files, exit any open program

Replacing the Hard DriveNOTICE: Use firm and even pressure to slide the hard drive into place. If you force the hard drive into place usingexcessive f