Dell XPS 8940 Service Manual
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Dell XPS 8940 Service Manual

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XPS 8940
Service Manual
Regulatory Model: D28M
Regulatory Type: D28M003
July 2020
Rev. A00

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Summary of Contents for Dell XPS 8940

  • Page 1 XPS 8940 Service Manual Regulatory Model: D28M Regulatory Type: D28M003 July 2020 Rev. A00...
  • Page 2 A WARNING indicates a potential for property damage, personal injury, or death. © 2020 Dell Inc. or its subsidiaries. All rights reserved. Dell, EMC, and other trademarks are trademarks of Dell Inc. or its subsidiaries. Other trademarks may be trademarks of their respective owners.

  • Page 3: Table Of Contents

    Transporting sensitive components............................ 8 After working inside your computer............................ 8 Chapter 2: Removing and installing components................9 Recommended tools................................9 Screw list....................................9 Major components of XPS 8940............................10 Left-side cover..................................12 Removing the left-side cover............................12 Installing the left-side cover............................13 Optical drive (optional)................................ 14 Removing the optical drive............................14...
  • Page 4 Installing the graphics card............................36 Coin-cell battery.................................. 38 Removing the coin-cell battery............................38 Installing the coin-cell battery............................39 Power-supply unit................................40 Removing the power-supply unit..........................40 Installing the power-supply unit........................... 43 Processor fan and heat-sink assembly..........................44 Removing the processor fan and heat-sink assembly....................44 Installing the processor fan and heat-sink assembly....................45 Processor....................................46 Removing the processor...............................46...
  • Page 5 Chapter 6: Getting help and contacting Dell..................75 Contents...

  • Page 6: Chapter 1: Working Inside Your Computer

    You should only perform troubleshooting and repairs as authorized or directed by the Dell technical assistance team. Damage due to servicing that is not authorized by Dell is not covered by your warranty. See the safety instructions that is shipped with the product or at www.dell.com/regulatory_compliance.

  • Page 7: Electrostatic Discharge-Esd Protection

    Due to the increased density of semiconductors used in recent Dell products, the sensitivity to static damage is now higher than in previous Dell products. For this reason, some previously approved methods of handling parts are no longer applicable.

  • Page 8: Transporting Sensitive Components

    Transporting sensitive components When transporting ESD sensitive components such as replacement parts or parts to be returned to Dell, it is critical to place these parts in anti-static bags for safe transport.

  • Page 9: Chapter 2: Removing And Installing Components

    Removing and installing components Recommended tools The procedures in this document may require the following tools: • Phillips screwdriver #1 • Flat-head screwdriver • Plastic scribe Screw list NOTE: When removing screws from a component, it is recommended to note the screw type, the quantity of screws, and then place them in a screw storage box.

  • Page 10: Major Components Of Xps 8940

    Screw image Voltage regulator heat sink Chassis Captive screw Front I/O bracket Chassis #6-32 System board Chassis #6-32 System board Chassis #6-32x3.8 Major components of XPS 8940 The following image shows the major components of XPS 8940. Removing and installing components...
  • Page 11 Removing and installing components...

  • Page 12: Left-Side Cover

    1. processor fan and heat-sink assembly 2. voltage regulator heat sink (optional) 3. hard drive 4. hard-drive cage 5. wireless card 6. solid-state drive 7. system board 8. memory modules 9. hard-drive cage 10. optical drive (optional) 11. power-button module 12.

  • Page 13: Installing The Left-Side Cover

    Steps 1. Loosen the two captive screws that secure the left-side cover to the chassis. 2. Using the tab on the left-side cover, slide and lift the left-side cover off the chassis. Installing the left-side cover Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following images indicate the location of the left-side cover and provide a visual representation of the installation procedure.

  • Page 14: Optical Drive (Optional)

    Steps 1. Align the tabs on the left-side cover with the slots on the chassis, and slide it towards the front of the computer. 2. Tighten the two captive screws that secure the left-side cover to the chassis. Next steps 1.
  • Page 15 About this task The following images indicate the location of the optical drive and provide a visual representation of the removal procedure. Removing and installing components...

  • Page 16: Installing The Optical Drive

    Steps 1. Disconnect the power and data cables from the optical drive. 2. Pull the release tab on the optical-drive cage towards the bottom of the computer. 3. Pull to slide out the optical drive through the front of the computer. 4.
  • Page 17 Steps 1. Align the tabs on the optical-drive bezel with slots on the optical drive and snap it in place. 2. Align the screw hole on the optical-drive bracket with the screw hole on the optical drive. 3. Replace the screw (M2x3) that secures the optical-drive bracket to the optical drive. 4.

  • Page 18: Power Button

    Power button Removing the power button Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the left-side cover. 3. Remove the front cover. About this task The following images indicate the location of the power button and provide a visual representation of the removal procedure. Steps 1.

  • Page 19: Front Cover

    Steps 1. Slide the power-button module into the chassis until it snaps into place. 2. Connect the power-button cable to the system board. Next steps 1. Install the front cover. 2. Install the left-side cover. 3. Follow the procedure in After working inside your computer.

  • Page 20: Installing The Front Cover

    Steps 1. Place the computer in an upright position. 2. Gently pry and release the front-cover tabs from the top-left, working down sequentially to the bottom-left tab. 3. Swing the front cover outwards, away from the chassis, and remove the cover. Installing the front cover Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.

  • Page 21: Inch Hard Drive

    Steps 1. Place the computer in an upright position. 2. Insert the right-side front-cover tabs into the corresponding slots on the chassis. 3. Push the left-side of the front cover towards the chassis, snapping the slots into position. Next steps 1.

  • Page 22: Installing The 2.5-Inch Hard Drive

    Steps 1. Lay the computer on the right side. 2. Disconnect the data and power cables from the hard drive. 3. Press the release tabs on the hard-drive carrier and slide the hard-drive carrier out of the hard-drive cage. 4. Pry the hard-drive carrier to release the tabs on the carrier from the slots on the hard drive. 5.
  • Page 23 The following images indicate the location of the 2.5-inch hard-drive assembly and provide a visual representation of the installation procedure. Steps 1. Place the hard drive into the hard-drive carrier and align the tabs on the carrier with the slots on the hard drive. 2.

  • Page 24: Inch Hard Drive

    3.5-inch hard drive Removing the 3.5-inch hard drive Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the left-side cover. About this task The following images indicate the location of the 3.5-inch hard-drive assembly and provide a visual representation of the removal procedure.

  • Page 25: Installing The 3.5-Inch Hard Drive

    5. Lift the hard-drive assembly away from the chassis. 6. Remove the four screws (#6-32) that secure the hard drive to the hard-drive cage. 7. Slide the hard drive from the hard-drive cage. Installing the 3.5-inch hard drive Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following images indicate the location of the 3.5-inch hard-drive assembly and provide a visual representation of the installation procedure.

  • Page 26: Chassis Fan

    5. Route the power cable and data cable through the routing guides on the hard-drive assembly and connect the cables to the hard drive. 6. Replace the screw (#6-32) that secures the hard-drive assembly to the chassis. Next steps 1. Install the left-side cover.

  • Page 27: Installing The Chassis Fan

    Installing the chassis fan Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following images indicate the location of the chassis fan and provide a visual representation of the installation procedure. Steps 1.

  • Page 28: Memory Modules

    2. Route the rubber grommets through the slots on fan and push the rubber grommets until the fan snaps into position. 3. Connect the fan cable to the system board. Next steps 1. Install the left-side cover. 2. Follow the procedure in After working inside your computer.

  • Page 29: Installing The Memory Modules

    Steps 1. Lay the chassis on the right side. 2. Use your fingertips to carefully spread apart the securing-clips on each end of the memory-module slot. 3. Grasp the memory module near the securing clip, and then gently ease the memory module out of the memory-module slot. CAUTION: To prevent damage to the memory module, hold the memory module by the edges.

  • Page 30: Wireless Card

    Steps 1. Align the notch on the memory module with the tab on the memory-module slot. 2. Insert the memory module into the memory-module connector until the memory module snaps into position and the securing clip locks in place. CAUTION: To prevent damage to the memory module, hold the memory module by the edges.

  • Page 31: Installing The Wireless Card

    Steps 1. Lay the computer on the right side. 2. Remove the screw (M2x3) that secures the wireless card to the system board. 3. Slide and lift the wireless-card bracket off the wireless card. 4. Disconnect the antenna cables from the wireless card. 5.
  • Page 32 Steps 1. Connect the antenna cables to the wireless card. The following table provides the antenna-cable color scheme for the wireless card that is supported by your computer. Table 2. Antenna-cable color scheme Connectors on the wireless card Antenna-cable color Main (white triangle) White Auxiliary (black triangle)

  • Page 33: Solid-State Drive/Intel Optane

    Solid-state drive/Intel Optane Installing the solid-state drive/Intel Optane Prerequisites CAUTION: Solid-state drives are fragile. Exercise care when handling the solid-state drive. If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following images indicate the location of the solid-state drive/Intel Optane and provide a visual representation of the installation procedure.

  • Page 34: Removing The Solid-State Drive/Intel Optane

    Removing the solid-state drive/Intel Optane Prerequisites NOTE: You must disable the Intel Optane memory before removing Intel Optane from your computer. For more information about disabling the Intel Optane memory, see Disabling Intel Optane. 1. Follow the procedure in Before working inside your computer.
  • Page 35 Removing and installing components...

  • Page 36: Installing The Graphics Card

    Steps 1. Lay the computer on the right side. 2. Disconnect the power cables from the graphics card and remove them from the routing guides on the graphics -card support bracket. NOTE: This step is applicable only for computers that are shipped with a graphics-card support bracket. 3.
  • Page 37 About this task The following images indicate the location of the graphics card and provide a visual representation of the installation procedure. Removing and installing components...

  • Page 38: Coin-Cell Battery

    Steps 1. Align the graphics card with the PCI-Express card connector on the system board. NOTE: To install the NVIDIA GeForce RTX 2080 graphics card, rotate and install the graphics card. 2. Using the alignment post, connect the card in the connector and press down firmly. Ensure that the card is firmly seated. 3.

  • Page 39: Installing The Coin-Cell Battery

    Steps 1. Lay the computer on the right side. 2. Using your finger, push the coin-cell battery-release lever on the coin-cell battery socket to release the coin-cell battery out of the socket. 3. Remove the coin-cell battery. Installing the coin-cell battery Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.

  • Page 40: Power-Supply Unit

    Insert the coin-cell battery into the socket with the positive side (+) label facing up and snap the battery in the socket. Next steps 1. Install the graphics card. 2. Install the left-side cover. 3. Follow the procedure in After working inside your computer.
  • Page 41 Removing and installing components...
  • Page 42 Steps 1. Lay the computer on the right side. 2. Disconnect the power cables from the system board and remove them from the routing guides on the chassis. Removing and installing components...

  • Page 43: Installing The Power-Supply Unit

    3. Remove the three screws (#6-32) that secure the power-supply unit to the chassis. 4. Press the securing clip and slide the power-supply unit away from the back of the chassis. 5. Lift the power-supply unit off the chassis. Installing the power-supply unit Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.

  • Page 44: Processor Fan And Heat-Sink Assembly

    Steps 1. Slide the power-supply unit into the chassis until the securing tab snaps into position. 2. Replace the three screws (#6-32) that secure the power-supply unit to the chassis. 3. Route the power cable through the routing guides on the chassis and connect the power cables to their respective connectors on the system board.

  • Page 45: Installing The Processor Fan And Heat-Sink Assembly

    Steps 1. Disconnect the processor-fan cable from the system board. 2. In the reverse sequential order (4->3->2->1), loosen the captive screws that secure the processor fan and heat-sink assembly to the system board. 3. Lift the processor fan and heat-sink assembly off the system board. Installing the processor fan and heat-sink assembly Prerequisites CAUTION:...

  • Page 46: Processor

    Steps 1. Align the numbering on the processor fan and heat-sink assembly with the numbering on the system board. 2. In the sequential order (1->2->3->4), tighten the captive screws that secure the processor fan and heat-sink assembly to the system board.

  • Page 47: Installing The Processor

    Steps 1. Press the release lever down and then push it away from the processor to release it from the securing tab. 2. Extend the release lever completely and open the processor cover. CAUTION: When removing the processor, do not touch any of the pins inside the socket or allow any objects to fall on the pins in the socket.

  • Page 48: Voltage Regulator Heat Sink (Optional)

    Steps 1. Ensure that the release lever on the processor socket is fully extended in the open position. NOTE: The pin-1 corner of the processor has a triangle that aligns with the triangle on the pin-1 corner on the processor socket. When the processor is properly seated, all four corners are aligned at the same height. If one or more corners of the processor are higher than the others, the processor is not seated properly.

  • Page 49: Installing The Voltage Regulator Heat Sink

    Steps 1. Loosen the captive screws that secure the voltage regulator heat sink to the system board. 2. Lift the voltage regulator heat sink off the system board. Installing the voltage regulator heat sink Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following images indicate the location of the voltage regulator heat sink and provide a visual representation of the installation procedure.

  • Page 50: System Board

    Steps 1. Align and place the voltage regulator heat sink on the system board. 2. Tighten the captive screws that secure the voltage regulator heat sink to the system board. Next steps 1. Install the left-side cover. 2. Follow the procedure in After working inside your computer.
  • Page 51 About this task Figure 1. System-board components 1. processor power-cable connector (ATX CPU1) 2. processor power-cable connector (ATX CPU) 3. processor 4. processor-fan cable connector (FAN CPU) 5. memory-module slot (DIMM3) 6. memory-module slot (DIMM1) 7. memory-module slot (DIMM4) 8. memory-module slot (DIMM2) 9.
  • Page 52 Removing and installing components...
  • Page 53 Steps 1. Lay the computer on the right side. 2. Remove the screw (#6-32) that secures the front I/O-bracket to the chassis. 3. Rotate and remove the front I/O-bracket from the chassis. 4. Disconnect all the cables that are connected to the system board. 5.

  • Page 54: Installing The System Board

    7. Remove the screw (#6-32x3.8) and that secures the system board to the chassis. 8. Lift the system board at an angle and remove it off the chassis. Installing the system board Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task Figure 2.
  • Page 55 20. PCIe x16 slot 21. PCIe x1 slot 22. chassis-fan cable connector (FAN SYS) The following images indicate the location of the system board and provide a visual representation of the installation procedure. Removing and installing components...
  • Page 56 Steps 1. Slide the back I/O-ports on the system board into the front I/O-slots on the chassis and align the screw holes on the system board with the screw holes on the chassis. 2. Replace the screw (#6-32x3.8) that secures the system board to the chassis. 3.
  • Page 57 6. Align the front I/O-bracket with the slots on the chassis. 7. Replace the screw (#6-32) that secures the front I/O-bracket to the chassis. Next steps 1. Install the processor. 2. Install the processor fan and heat-sink assembly. 3. Install the coin-cell battery.

  • Page 58: Chapter 3: Drivers And Downloads

    Drivers and downloads When troubleshooting, downloading or installing drivers it is recommended that you read the Dell Knowledge Based article, Drivers and Downloads FAQ SLN128938. Drivers and downloads...

  • Page 59: Chapter 4: System Setup

    Boot Sequence allows you to bypass the System Setup–defined boot device order and boot directly to a specific device (for example: optical drive or hard drive). During the Power-on Self Test (POST), when the Dell logo appears, you can: •...

  • Page 60: System Setup Options

    • Bring up the one-time boot menu by pressing F12 key The one-time boot menu displays the devices that you can boot from including the diagnostic option. The boot menu options are: • Removable Drive (if available) • STXXXX Drive (if available) NOTE: XXX denotes the SATA drive number.
  • Page 61 Table 3. System setup options—System information menu (continued) General-System Information Current Clock Speed Displays the current processor clock speed. Minimum Clock Speed Displays the minimum processor clock speed. Maximum Clock Speed Displays the maximum processor clock speed. Processor L2 Cache Displays the Processor L2 Cache size.
  • Page 62 Table 4. System setup options—System Configuration menu (continued) System Configuration M.2 PCIe SSD-2 Displays the M.2 PCIe SSD information of the computer. SMART Reporting Enable or disable SMART Reporting during system startup. USB Configuration Enable Boot Support Enable or disable booting from USB mass storage devices such as external hard drive, optical drive, and USB drive.
  • Page 63 Table 7. System setup options—Secure Boot menu (continued) Secure Boot Secure Boot Mode Modifies the behavior of Secure Boot to allow evaluation or enforcement of UEFI driver signatures. • Deployed Mode-Default: Enabled • Audit Mode-Default: Disabled Deployed Mode Enable or disable the deployed mode. Audit Mode Enable or disable the audit mode.
  • Page 64 SupportAssist System Resolution Auto OS Recovery Threshold Control the automatic boot flow for SupportAssist System Resolution Console and for Dell OS Recovery tool. SupportAssist OS Recovery Enable or disable the boot flow for SupportAssist OS Recovery tool in the event of...

  • Page 65: System And Setup Password

    System and setup password Table 14. System and setup password Password type Description System password Password that you must enter to log on to your system. Setup password Password that you must enter to access and make changes to the BIOS settings of your computer.

  • Page 66: Real Time Clock (Rtc) Reset

    Real Time Clock (RTC) reset The Real Time Clock (RTC) reset function allows you or the service technician to recover the recently launched model Dell computers from No POST/No Boot/No Power situations. You can initiate the RTC reset on the computer from a power-off state only if it is connected to AC power.

  • Page 67: Chapter 5: Troubleshooting

    Troubleshooting SupportAssist diagnostics About this task The SupportAssist diagnostics (previously known as ePSA diagnostics) performs a complete check of your hardware. The SupportAssist diagnostics is embedded in the BIOS and is launched by it internally. The SupportAssist diagnostics provides a set of options for particular devices or device groups.

  • Page 68: Diagnostic Error Messages

    For example, the power and battery-status light blinks amber two times followed by a pause, and then blinks white three times followed by a pause. This 2,3 pattern continues until the computer is turned off indicating no memory or RAM is detected. The following table shows different power and battery-status light patterns and associated problems.
  • Page 69 One or more memory modules may be faulty or improperly seated. Reinstall the memory modules or, if necessary, replace them. DISK C: FAILED INITIALIZATION The hard drive failed initialization. Run the hard drive tests in Dell Diagnostics. DRIVE NOT READY The operation requires a hard drive in the bay before it can continue.
  • Page 70 KEYBOARD STUCK KEY FAILURE For external keyboards or keypads, check the cable connection. Restart the computer, and avoid touching the keyboard or keys during the boot routine. Run the Stuck Key test in Dell Diagnostics. LICENSED CONTENT IS NOT ACCESSIBLE IN...

  • Page 71: Enabling Intel Optane Memory

    The operating system cannot find a specific track on the hard drive. SHUTDOWN FAILURE A chip on the system board may be malfunctioning. Run the System Set tests in Dell Diagnostics. If the message reappears, Contact Dell. TIME-OF-DAY CLOCK LOST POWER System configuration settings are corrupted. Connect your computer to an electrical outlet to charge the battery.

  • Page 72: Recovering The Operating System

    You can also download it from the Dell Support website to troubleshoot and fix your computer when it fails to boot into their primary operating system due to software or hardware failures.

  • Page 73: Flashing The Bios From The F12 One-Time Boot Menu

    Most of the Dell computers built after 2012 have this capability, and you can confirm by booting your computer to the F12 One-Time Boot Menu to see if BIOS FLASH UPDATE is listed as a boot option for your computer. If the option is listed, then the BIOS supports this BIOS update option.

  • Page 74: Flea Power Release

    4. Wait for 30 seconds. 5. Turn on the wireless router. 6. Turn on the modem. 7. Turn on your computer. Flea power release About this task Flea power is the residual static electricity that remains on the computer even after it has been powered off and the battery has been removed.
  • Page 75 Getting help and contacting Dell Self-help resources You can get information and help on Dell products and services using these self-help resources: Table 17. Self-help resources Self-help resources Resource location Information about Dell products and services www.dell.com My Dell Tips Contact Support In Windows search, type Contact Support, and press Enter.

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