Dell Latitude 3420 Service Manual
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Dell Latitude 3420 Service Manual

Computers with integrated graphics
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Latitude 3420
Service Manual for computers with integrated
graphics
Regulatory Model: P144G
Regulatory Type: P144G001/P144G002
July 2021
Rev. A01

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Summary of Contents for Dell Latitude 3420

  • Page 1 Latitude 3420 Service Manual for computers with integrated graphics Regulatory Model: P144G Regulatory Type: P144G001/P144G002 July 2021 Rev. A01...
  • Page 2 A WARNING indicates a potential for property damage, personal injury, or death. © 2021 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

    Contents Chapter 1: Working inside your computer..................7 Safety instructions................................7 Before working inside your computer........................7 Entering Service Mode..............................8 Exiting Service Mode..............................8 Safety precautions................................ 8 Electrostatic discharge—ESD protection....................... 9 ESD field service kit ..............................9 Transporting sensitive components.........................10 After working inside your computer........................
  • Page 4 Installing the hard-disk drive bracket........................34 Installing the hard-disk drive assembly........................35 WLAN card..................................36 Removing the WLAN card............................36 Installing the WLAN card............................37 WWAN card..................................38 Removing the WWAN card............................38 Installing the WWAN card............................39 System fan...................................41 Removing the system fan............................41 Installing the system fan............................
  • Page 5 Deleting or changing an existing system setup password.................111 Clearing CMOS settings..............................112 Clearing BIOS (System Setup) and System passwords..................112 Chapter 5: Troubleshooting......................113 Handling swollen Lithium-ion batteries........................113 Dell SupportAssist Pre-boot System Performance Check diagnostics...............113 Running the SupportAssist Pre-Boot System Performance Check............... 114 Contents...
  • Page 6 LCD Built-in Self Test (BIST)..........................115 System-diagnostic lights..............................115 Recovering the operating system..........................117 Real-Time Clock (RTC Reset)............................117 Backup media and recovery options..........................117 WiFi power cycle................................118 Drain residual flea power (perform hard reset)......................118 Chapter 6: Getting help and contacting Dell................119 Contents...

  • Page 7: Chapter 1: Working Inside Your Computer

    Damage due to servicing that is not authorized by Dell is not covered by your warranty. Read and follow the safety instructions that came with the product.

  • Page 8: Entering Service Mode

    1. Shut down your computer and disconnect the AC adapter. 2. Hold <B> key on the keyboard and press the power button for 3 seconds or until the Dell logo appears on the screen. 3. Press any key to continue.

  • Page 9: Electrostatic Discharge-Esd Protection

    ESD protection is an increasing concern. 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 10: Transporting Sensitive Components

    It is recommended that all field service technicians use the traditional wired ESD grounding wrist strap and protective anti-static mat at all times when servicing Dell products. In addition, it is critical that technicians keep sensitive parts separate from all insulator parts while performing service and that they use anti-static bags for transporting sensitive components.

  • Page 11: Chapter 2: Removing And Installing Components

    Removing and installing components NOTE: The images in this document may differ from your computer depending on the configuration you ordered. Recommended tools The procedures in this document may require the following tools: ● Phillips #0 screwdriver ● Plastic scribe Screw List The following table shows the screw list and the image of the screws.
  • Page 12 Table 1. Screw list (continued) Component Screw type Quantity Image Display hinges M2.5x6 M2.5x4 Hinge bracket M2.5x2.5 M2.5x3 Captive screws Heatsink assembly 7 (For systems enabled with discrete graphic card) 4 (For systems enabled with integrated graphic card) Power adapter port M2x3 Ethernet port M2x5...

  • Page 13: Major Components Of Your System

    Major components of your system 1. Base cover Removing and installing components...

  • Page 14: Microsd-Card

    19. Power adapter port 20. WLAN NOTE: Dell provides a list of components and their part numbers for the original system configuration purchased. These parts are available according to warranty coverages purchased by the customer. Contact your Dell sales representative for purchase options.

  • Page 15: Installing The Microsd-Card

    Steps 1. Push the microSD-card to eject it from the slot. 2. Remove the microSD-card from the system. Installing the MicroSD-card Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image provides a visual representation of the MicroSD-card installation procedure.

  • Page 16: Installing The Sim Card Tray

    Steps 1. Insert the SIM card removal pin into the release hole to release the SIM card tray. 2. Push the pin to disengage the lock, and eject the SIM card tray. 3. Slide the SIM card tray out of the slot on the computer. 4.

  • Page 17: Base Cover

    Steps 1. Insert the SIM card removal pin into the release hole to remove the SIM card tray. 2. Push the pin to disengage the lock, and eject the SIM card tray. 3. Slide the SIM card tray out of the slot on the computer. 4.
  • Page 18 About this task The following images indicate the location of the base cover and provide a visual representation of the removal procedure. Removing and installing components...

  • Page 19: Installing The Base Cover

    Steps 1. Loosen the eight captive screws that secure the base cover to the palmrest assembly. 2. Using a plastic scribe, pry open the base cover starting from the recesses located in the U-shaped indents near the hinges at the top edge of the base cover. 3.

  • Page 20: Battery Cable

    Steps 1. Align and place the base cover on the palmrest assembly, and snap the base cover latches into place. 2. Tighten the eight captive screws to secure the base cover to the computer chassis. Next steps 1. Exit the service mode 2.

  • Page 21: Removing The Battery Cable

    ● If the battery gets stuck inside your computer as a result of swelling, do not try to release it as puncturing, bending, or crushing a lithium-ion battery can be dangerous. In such an instance, contact Dell technical support for assistance. See www.dell.com/contactdell.

  • Page 22: Installing The Battery Cable

    Installing the battery cable Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the battery cable and provides a visual representation of the installation procedure. Steps 1.

  • Page 23: Installing The Memory Module

    4. Enter the service mode. 5. Remove the base cover. About this task The following image indicates the location of the memory module and provides a visual representation of the removal procedure. NOTE: The location of the memory module may vary depending on your system. Steps 1.
  • Page 24 About this task The following image indicates the location of the memory module and provides a visual representation of the installation procedure. NOTE: The location of the memory module may vary depending on your system. Steps 1. Lift the mylar to find the memory module slot. 2.

  • Page 25: M.2 Solid-State Drive

    5. Follow the procedure in after working inside your computer. M.2 solid-state drive Removing the M.2 2230 solid-state drive Prerequisites 1. Follow the procedure in before working inside your computer. 2. Remove the microSD-card. 3. Remove the SIM card tray for 4G LTE enabled systems.

  • Page 26: Removing The M.2 2280 Solid-State Drive

    Steps 1. Align the notch on the solid-state drive with the tab on the solid-state drive slot. 2. Slide the solid-state drive into the solid-state drive slot on the system board. 3. Replace the (M2x3) screw to secure the solid-state drive to the system board. Next steps 1.

  • Page 27: Installing The M.2 2280 Solid-State Drive

    Steps 1. Remove the (M2x3) screw that secures the solid-state drive to the system board. 2. Slide and remove the solid-state drive from the solid-state drive slot on the system board. Installing the M.2 2280 solid-state drive Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the solid-state drive and provides a visual representation of the installation procedure.

  • Page 28: M.2 Solid-State Drive Conversion Bracket

    2. Slide the solid-state drive into the solid-state drive slot on the system board. 3. Replace the (M2x3) screw to secure the solid-state drive to the system board. Next steps 1. Install the base cover. 2. Exit the service mode 3.

  • Page 29: M.2 Solid-State Drive Conversion Plate

    Steps 1. Remove the (M2x3) screw that secures the solid-state drive conversion bracket to the solid-state drive conversion plate. 2. Depending on the type of solid-state drive (M.2 2230/ M.2 2280), turn, align and place the solid-state drive conversion bracket into the slot. 3.

  • Page 30: Installing The M.2 Solid-State Drive Conversion Plate

    About this task The following image indicates the location of the M.2 solid-state drive conversion plate and provides a visual representation of the removal procedure. Steps 1. Remove the two (M2x3) screws that secures the solid-state drive conversion plate to the system board. 2.

  • Page 31: Hard-Disk Drive Assembly

    Steps 1. Align and place the solid-state drive conversion plate on the system board. 2. Install the two (M2x3) screws to secure the solid-state drive conversion plate to the system board. Next steps 1. Install the SSD. 2. Install the base cover.

  • Page 32: Removing The Hard-Disk Drive Bracket

    Steps 1. Lift and disconnect the hard-disk drive cable from the connector on the system board. 2. Loosen the three (M2X4.5) screws that secure the hard-disk drive assembly to the palmrest assembly. 3. Lift and remove the hard-disk drive assembly from the slot on the palmrest assembly. Removing the hard-disk drive bracket Prerequisites 1.
  • Page 33 Steps 1. Disconnect the hard-disk drive cable from the connector on the hard-disk drive bracket. 2. Remove the four (M3x3) screws that secure the hard-disk drive to the hard-disk drive bracket. 3. Flip the hard-disk drive bracket, lift the silver foil, and remove the hard-disk drive from the hard-disk drive bracket. Removing and installing components...

  • Page 34: Installing The Hard-Disk Drive Bracket

    Installing the hard-disk drive bracket Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the hard-disk drive bracket and provides a visual representation of the installation procedure.

  • Page 35: Installing The Hard-Disk Drive Assembly

    Steps 1. Lift the silver foil, align and place the hard-disk drive in the hard-disk drive bracket. 2. Install the four (M3x3) screws to secure the hard-disk drive to the hard-disk drive bracket. 3. Connect the hard-disk drive cable to the connector on the hard-disk drive bracket. Next steps 1.

  • Page 36: Wlan Card

    Next steps 1. Install the base cover. 2. Exit the service mode 3. Install the SIM card tray for 4G LTE enabled systems. 4. Install the microSD-card. 5. Follow the procedure in after working inside your computer. WLAN card Removing the WLAN card Prerequisites 1.

  • Page 37: Installing The Wlan Card

    Steps 1. Remove the screw (M2x3) that secures WLAN card bracket to the WLAN card on the system board. 2. Lift and remove the WLAN card bracket from the WLAN card that secures the two antenna cables. 3. Disconnect the antenna cables from the connectors on the WLAN card. 4.

  • Page 38: Wwan Card

    Table 2. Antenna cable guide Cable color Connector White cable (Main) White triangle (△) on the WLAN module of the system board Black cable (Aux) Solid triangle (▲) on the WLAN module of the system board 2. Align the notch on the WLAN card with the tab on the WLAN card slot. 3.

  • Page 39: Installing The Wwan Card

    Steps 1. Open the mylar sheet that covers the WWAN card. 2. Remove the screw (M2x3) that secures WWAN card bracket to the WWAN card on the system board. 3. Lift and remove the WWAN card bracket from the WWAN card that secures the two antenna cables. 4.
  • Page 40 Steps 1. Connect the two antenna cables to the connectors on the WWAN card. NOTE: The antenna cable connectors are fragile and utmost care should be taken while replacing them. Table 3. Antenna cable guide Cable color Connector White cable (Main) White triangle (△) on the WWAN module of the system board Black cable (Aux)

  • Page 41: System Fan

    4. Install the microSD-card. 5. Follow the procedure in after working inside your computer. System fan Removing the system fan Prerequisites 1. Follow the procedure in before working inside your computer. 2. Remove the microSD-card. 3. Remove the SIM card tray for systems enabled with 4G LTE.

  • Page 42: Installing The System Fan

    Installing the system fan Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the system fan and provides a visual representation of the installation procedure. Steps 1.

  • Page 43: Battery

    Battery Removing the 3-cell battery Prerequisites 1. Follow the procedure in before working inside your computer. 2. Remove the microSD-card. 3. Remove the SIM card tray for 4G LTE enabled systems. 4. Remove the base cover. About this task The following image indicates the location of the battery and provides a visual representation of the removal procedure. Steps 1.

  • Page 44: Installing The 3-Cell Battery

    3. Lift and remove the battery from the palmrest assembly. 4. Slide the metal above the connector on the battery to unlock. 5. Peel the adhesive tapes and unroute the battery cable from routing channel in the battery. 6. Disconnect the battery cable from the connector on the battery. Installing the 3-cell battery Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.

  • Page 45: Removing The 4-Cell Battery

    4. Align and place the battery in the slot on the palmrest assembly. 5. Install the three (M2X3) screws to secure the battery in place. 6. Connect the battery cable to the connector on the system board. Next steps 1. Install the base cover.

  • Page 46: Installing The 4-Cell Battery

    Steps 1. Disconnect the battery cable from the connector on the system board. 2. Remove the four (M2X3) screws that secure the battery in place. 3. Lift and remove the battery from the palmrest assembly. 4. Slide the metal above the connector on the battery to unlock. 5.
  • Page 47 Steps 1. Connect the battery cable to the connector on the battery. 2. Slide the metal above the connector on the battery to lock. 3. Route the battery cable through the routing channel in the battery and adhere the adhesive tapes. 4.

  • Page 48: I/O Cable

    I/O cable Removing the I/O cable Prerequisites 1. Follow the procedure in before working inside your computer. 2. Remove the SIM card tray for 4G LTE enabled systems. 3. Enter the service mode. 4. Remove the base cover. About this task The following image indicates the location of the I/O cable and provides a visual representation of the removal procedure.

  • Page 49: Display Assembly

    About this task The following image indicates the location of the I/O cable and provides a visual representation of the installation procedure. Steps 1. Route the I/O cable through the routing guides and adhere the adhesive tape to secure the I/O cable in place. 2.
  • Page 50 8. Remove the M.2 SSD conversion plate for systems enabled with 4G LTE. 9. Remove the WLAN card. 10. Remove the WWAN card for systems enabled with 4G LTE. 11. Remove the cable. About this task The following images indicate the location of the display assembly and provide a visual representation of the removal procedure. Removing and installing components...
  • Page 51 Steps 1. Unroute the display cable from the routing guides in the palmrest assembly. 2. Peel the adhesive tape that secures the display cable in place. 3. Open the latch and disconnect the display cable from the connector on the system board. 4.

  • Page 52: Installing The Display Assembly

    Installing the display assembly 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 display assembly and provide a visual representation of the installation procedure.
  • Page 53 Steps 1. Align and place the system chassis under the hinges of the display assembly. 2. Press the left and right hinges in downward direction toward the palmrest assembly. 3. Install the three (M2.5x6) and two (M2.5x4) screws to secure the display hinges to the palmrest assembly. 4.

  • Page 54: Display Panel

    11. Follow the procedure in after working inside your computer. Display panel Removing the display panel Prerequisites 1. Follow the procedure in before working inside your computer. 2. Enter the service mode. 3. Remove the microSD-card. 4. Remove the SIM card tray for 4G LTE enabled systems.
  • Page 55 Removing and installing components...
  • Page 56 Removing and installing components...

  • Page 57: Installing The Display Panel

    Steps 1. Remove the six (M2.5x2.5) and two (M2.5x3) screws that secure the left and right hinge brackets in place. 2. Gently flip over the display panel. 3. Peel the adhesive tape, open the latch and disconnect the display cable from the connector on the display panel. 4.
  • Page 58 Removing and installing components...
  • Page 59 Steps 1. Align and place the display panel on the display assembly. 2. Connect the display cable to the connector on the display panel, close the latch and affix the adhesive tape. 3. Install the six (M2.5x2.5) and two (M2.5x3) screws to secure the left and right hinge brackets in place. 4.

  • Page 60: Display Bezel

    Display bezel Removing the display bezel Prerequisites 1. Follow the procedure in before working inside your computer. 2. Remove the microSD-card. 3. Remove the SIM card tray for 4G LTE enabled systems. 4. Enter the service mode. 5. Remove the base cover.

  • Page 61: Installing The Display Bezel

    Installing the display bezel Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the display bezel and provides a visual representation of the installation procedure. Steps Align the display bezel with the display assembly.

  • Page 62: Heatsink Assembly

    Heatsink assembly Removing the heatsink assembly Prerequisites 1. Follow the procedure in before working inside your computer. 2. Remove the microSD-card. 3. Remove the SIM card tray for systems enabled with 4G LTE. 4. Enter the service mode. 5. Remove the base cover.

  • Page 63: Power Adapter Port

    About this task The following image indicates the location of the heatsink assembly and provides a visual representation of the installation procedure. Steps 1. Align and place the heatsink assembly into the slot on the system board. 2. Tighten the four captive screws (in order, 1>2>3>4) to secure the heatsink assembly to the system board. Next steps 1.

  • Page 64: Installing The Power Adapter Port

    About this task The following image indicates the location of the power adapter port and provides a visual representation of the removal procedure. Steps 1. Remove the (M2.5x6) and (M2.5x4) screws that secure the display hinges to the system. 2. Disconnect the power adapter port from the connector on the system board. 3.

  • Page 65: Coin-Cell Battery

    Steps 1. Align and place the power adapter port on the palmrest assembly. 2. Install the (M2x3) screw to secure the power adapter port to the palmrest assembly. 3. Connect the power adapter port to the connector on the system board. 4.

  • Page 66: Installing The Coin-Cell Battery

    The following image indicates the location of the coin-cell battery and provides a visual representation of the removal procedure. Steps 1. Disconnect the coin-cell battery cable from the connector on the I/O board. 2. Lift and remove the coin-cell battery from the palmrest assembly. Installing the coin-cell battery Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.

  • Page 67: Usb Cable

    Steps 1. Align and place the coin-cell battery on the palmrest assembly. 2. Connect the coin-cell battery cable to the connector on the I/O board. Next steps 1. Install the WWAN I/O boardfor systems enabled with 4G LTE. 2. Install the WWAN card for systems enabled with 4G LTE.

  • Page 68: Installing The Usb Cable

    About this task The following image indicates the location of the USB cable and provides a visual representation of the removal procedure. Steps 1. Open the latch and disconnect the USB cable from the connector on the system board. 2. Carefully peel the USB cable from the palmrest assembly. 3.

  • Page 69: Ethernet Port

    Steps 1. Connect the USB cable to the connector on the system board and close the latch. 2. Align and adhere the USB cable on the palmrest assembly. 3. Connect the USB cable to the connector on the I/O board and close the latch. Next steps 1.

  • Page 70: Installing The Ethernet Port

    Steps 1. Remove the (M2.5x4) and two (M2.5x6) screws to secure the hinge bracket on the palmrest assembly. 2. Lift the hinge in upward direction away from the palmrest assembly. 3. Remove the (M2x5) screw that secures the ethernet on the I/O board. 4.

  • Page 71: I/O Board

    Steps 1. Align and place the ethernet on the I/O board. 2. Install the (M2x5) screw to secure the ethernet on the I/O board. 3. Press the hinge in downward direction toward the palmrest assembly. 4. Install the (M2.5x4) and two (M2.5x6) screws to secure the hinge bracket on the palmrest assembly. Next steps 1.

  • Page 72: Installing The I/O Board

    NOTE: The following image is from systems without power-button board. The following image indicates the location of the I/O board and provides a visual representation of the removal procedure. Steps 1. For systems shipped with power button, peel the adhesive, open the latch and disconnect the power button cable from the connector on the I/O board.

  • Page 73: Power Button

    Steps 1. Align and place the I/O board into its slot on the palmrest assembly. 2. Install the two (M2x3) screws that secure the I/O board on the palmrest assembly. 3. Connect the USB cable and coin-cell cable to the connectors on the system board. 4.

  • Page 74: Installing The Power Button Without Fingerprint Reader

    7. Remove the ethernet port. About this task The following image indicates the location of the power button without fingerprint reader and provides a visual representation of the removal procedure. Steps Lift the power button off the palmrest assembly. Installing the power button without fingerprint reader About this task The following image indicates the location of the power button without fingerprint reader and provides a visual representation of the removal procedure.

  • Page 75: Removing The Power Button With Fingerprint Reader

    Steps Align and place the power button into the slot on the palmrest assembly. Next steps 1. Install the ethernet port. 2. Install the board. 3. Install the base cover. 4. Exit the service mode 5. Install the SIM card tray for 4G LTE enabled systems.

  • Page 76: Installing The Power Button With Fingerprint Reader

    Steps 1. Peel the power button cable with adhesive backing from the palmrest assembly. 2. Lift the power button with fingerprint reader off the palmrest assembly. Installing the power button with fingerprint reader About this task The following image indicates the location of the power button with fingerprint reader and provides a visual representation of the removal procedure.

  • Page 77: System Board

    System board Removing the system board Prerequisites 1. Follow the procedure in before working inside your computer. 2. Remove the microSD-card. 3. Remove the SIM card tray for 4G LTE enabled systems. 4. Remove the base cover. 5. Remove the battery. 6.
  • Page 78 Removing and installing components...

  • Page 79: Installing The System Board

    Steps 1. Remove the (M2.5x6) and the (M2.5x4) screws that secure the hinge to the palmrest assembly. 2. Lift the hinge in upward direction away from the palmrest assembly. 3. For 4G LTE enabled systems, peel the WWAN I/O board cable from the palmrest assembly. 4.
  • Page 80 1. System fan cable connector 2. I/O cable connector 3. Memory module connector 4. Display cable connector 5. Power adapter port connector 6. Keyboard backlit LED cable connector 7. Keyboard cable connector 8. Touchpad cable connector 9. Battery cable connector 10.
  • Page 81 Removing and installing components...
  • Page 82 Steps 1. Align and place the system board into the slot on the palmrest assembly. 2. Install the two (M2x2) screws to secure the system board in place. 3. Align and place the type-c bracket on the system board. 4. Install the two (M2x5) screws to secure the type-c bracket in place. 5.

  • Page 83: Speakers

    Speakers Removing the speaker Prerequisites 1. Follow the procedure in before working inside your computer. 2. Remove the microSD-card. 3. Remove the SIM card tray for 4G LTE enabled systems. 4. Remove the base cover. 5. Remove the battery. About this task The following image indicates the location of the speakers and provides a visual representation of the removal procedure.

  • Page 84: Installing The Speaker

    4. Unroute the speaker cable from the routing guides in the palmrest assembly. 5. Peel the adhesive tapes, lift and remove the speakers off the palmrest assembly. Installing the speaker Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the speakers and provides a visual representation of the installation procedure.

  • Page 85: Touchpad

    Next steps 1. Install the battery. 2. Install the base cover. 3. Install the SIM card tray for 4G LTE enabled systems. 4. Install the microSD-card. 5. Follow the procedure in after working inside your computer. Touchpad Removing the touchpad Prerequisites 1.

  • Page 86: Installing The Touchpad

    Installing the touchpad Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the touchpad and provides a visual representation of the installation procedure. Steps 1.

  • Page 87: Wwan I/O Board

    WWAN I/O board Removing the WWAN I/O board Prerequisites 1. Follow the procedure in before working inside your computer. 2. Remove the microSD card. 3. Remove the SIM card tray for 4G LTE enabled systems. 4. Remove the base cover. 5.

  • Page 88: Palmrest Assembly

    About this task The following image indicates the location of the WWAN I/O board and provides a visual representation of the installation procedure. NOTE: The following steps are applicable only for 4G LTE enabled systems. Steps 1. Connect the WWAN cable to the connector on the WWAN I/O board and close the latch. 2.

  • Page 89: Installing The Palmrest Assembly

    7. Remove the SSD. 8. Remove the M.2 SSD conversion bracket. 9. Remove the M.2 SSD conversion plate. 10. Remove the hard-disk drive. 11. Remove the WLAN card. 12. Remove the WWAN card for systems enabled with 4G LTE. 13. Remove the I/O board cable.
  • Page 90 Steps After performing the succeeding steps, you are left with the palmrest assembly. Next steps 1. Install the system board. 2. Install the WWAN I/O board for systems enabled with 4G LTE. 3. Install the cable. 4. Install the coin-cell battery.

  • Page 91: Camera

    Camera Removing the camera Prerequisites 1. Follow the procedure in before working inside your computer. 2. Remove the microSD-card. 3. Remove the SIM card tray for 4G LTE enabled systems. 4. Enter the service mode. 5. Remove the base cover. 6.

  • Page 92: Display Cable

    About this task The following image indicates the location of the camera and provides a visual representation of the installation procedure. Steps 1. Align and place the camera module into the slot on the display back-cover. 2. Connect the camera cable to the connector on the camera module. 3.

  • Page 93: Installing The Display Cable

    8. Remove the I/O board cable. 9. Remove the display assembly. 10. Remove the display bezel. 11. Remove the display panel. About this task The following image indicates the location of the display cable and provides a visual representation of the removal procedure. Steps 1.
  • Page 94 About this task The following image indicates the location of the display cable and provides a visual representation of the installation procedure. Steps 1. Connect the display cable from the connector on the camera module. 2. Connect the display cable from the connector on the display panel. 3.

  • Page 95: Display Back-Cover

    Display back-cover Removing the display back-cover Prerequisites 1. Follow the procedure in before working inside your computer. 2. Remove the microSD-card. 3. Remove the SIM card tray for 4G LTE enabled systems. 4. Enter the service mode. 5. Remove the base cover.
  • Page 96 About this task The following image indicates the location of the display back-cover and provides a visual representation of the installation procedure. Steps After performing the succeeding steps, you are left with the base cover assembly. Next steps 1. Install the display cable.

  • Page 97: Chapter 3: Drivers And Downloads

    Drivers and downloads When troubleshooting, downloading, or installing drivers, it is recommended that you read the Dell knowledge base article, Drivers and Downloads FAQs Drivers and downloads...

  • Page 98: Chapter 4: Bios Setup

    BIOS setup CAUTION: Unless you are an expert computer user, do not change the settings in the BIOS Setup program. Certain changes can make your computer work incorrectly. NOTE: Depending on the computer and its installed devices, the items listed in this section may or may not be displayed. NOTE: Before you change BIOS Setup program, it is recommended that you write down the BIOS Setup program screen information for future reference.

  • Page 99: One Time Boot Menu

    Depending on your system and its installed devices, the items that are listed in this section may or may not appear. Table 5. System setup options—System information menu Overview Latitude 3420 BIOS Version Displays the BIOS version number. Service Tag Displays the Service Tag of the system.
  • Page 100 Table 5. System setup options—System information menu (continued) Overview Maximum Clock Speed Displays the maximum processor clock speed. Minimum Clock Speed Displays the minimum processor clock speed. Current Clock Speed Displays the current processor clock speed. Core Count Displays the number of cores on the processor. Processor ID Displays the processor identification code.
  • Page 101 Table 6. System setup options—Boot Configuration menu (continued) Boot Configuration By default, the Secure Digital (SD) Card Boot option is not enabled. Secure Boot Enable Secure Boot Enable or disable the secure boot feature. By default, the option is disabled. Secure Boot Mode Allows you to modify the secure boot mode options.
  • Page 102 Table 8. System setup options—Storage menu (continued) Storage Port Enablement This page allows you to enable the onboard drives. By default, the SATA-1 option is enabled. By default, the M.2 PCIe SSD-1 option is enabled. SMART Reporting Enable SMART Reporting Enable or disable Self-Monitoring, Analysis, and Reporting Technology (SMART) during system startup.
  • Page 103 Table 10. System setup options—Connection menu (continued) Connection Wireless Device Enable WWAN/GPS (For systems with Enable or disable the internal WWAN/GPS device. By default, the option integrated video card only) enabled. WLAN Enable or disable the internal WLAN device. By default, the option enabled. Bluetooth Enable or disable the internal Bluetooth device.
  • Page 104 Power By default, the Enable USB Wake Support option is disabled. Wake on Dell USB-C Dock When enabled, connecting a Dell USB-C Dock will wake the system from standby. By default, the Wake on Dell USB-C Dock option is enabled.
  • Page 105 Table 12. System setup options—Security menu (continued) Security Intel SGX Enable Intel Software Guard Extensions (SGX) to provide a secured environment for running code/storing senstive information in the context of the main operating system. By default, the Software Control option is enabled. SMM Security Mitigation Enable or disable SMM Security Mitigation.
  • Page 106 Dell Auto operating system Recovery Controls the automatic boot flow for SupportAssist System Resolution Console Threshold and for Dell operating system Recovery Tool. By default, the threshold value is set to 2. Table 15. System setup options—System Management menu System Management Service Tag Display the Service Tag of the system.
  • Page 107 Table 15. System setup options—System Management menu (continued) System Management Wake on LAN Enable or disable the system to power on by special LAN signals when it receives a wakeup signal from the WLAN. By default, the Disabled option is selected. Auto on Time Enable to set the system to turn on automatically every day or on a preselected date and time.
  • Page 108 Table 18. System setup options—Virtualization menu Virtualization Intel Virtualization Technology Enable Intel Virtualization Technology Specify whether a Virtual Machine Monitor (VMM) can use the additional (VT) hardware capabilities that are provided by Intel Virtualization Technology. By default, the option is enabled. VT for Direct I/O Specify whether a Virtual Machine Monitor (VMM) can use the additional hardware capabilities that are provided by Intel Virtualization Technology for...

  • Page 109: Updating The Bios

    Steps 1. Go to www.dell.com/support. 2. Click Product support. In the Search support box, enter the Service Tag of your computer, and then click Search. NOTE: If you do not have the Service Tag, use the SupportAssist feature to automatically identify your computer. You can also use the product ID or manually browse for your computer model.

  • Page 110: Updating The Bios From The F12 One-Time Boot Menu

    One-Time boot menu on the computer. 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 111: System And Setup Password

    System and setup password Table 21. System and setup password Password type Description System password Password that you must enter to log in to your system. Setup password Password that you must enter to access and make changes to the BIOS settings of your computer. You can create a system password and a setup password to secure your computer.

  • Page 112: Clearing Cmos Settings

    Clearing BIOS (System Setup) and System passwords About this task To clear the system or BIOS passwords, contact Dell technical support as described at www.dell.com/contactdell. NOTE: For information on how to reset Windows or application passwords, refer to the documentation accompanying Windows or your application.

  • Page 113: Chapter 5: Troubleshooting

    ● Using a non-Dell or incompatible battery may increase the risk of fire or explosion. Replace the battery only with a compatible battery purchased from Dell that is designed to work with your Dell computer. Do not use a battery from other computers with your computer.

  • Page 114: Running The Supportassist Pre-Boot System Performance Check

    Running the SupportAssist Pre-Boot System Performance Check Steps 1. Turn on your computer. 2. As the computer boots, press the F12 key as the Dell logo appears. 3. On the boot menu screen, select the Diagnostics option. 4. Click the arrow at the bottom left corner.

  • Page 115: Lcd Power Rail Test (L-Bist)

    LCD Built-in Self Test (BIST) Dell laptops have a built-in diagnostic tool that helps you determine if the screen abnormality you are experiencing is an inherent problem with the LCD (screen) of the Dell laptop or with the video card (GPU) and PC settings.
  • Page 116 (AC, battery, coin cell) and errors drain flea power by pressing and holding down power button for 3~5 seconds. CPU failure ● Run the Dell Support Assist/Dell Diagnostics tool. ● If problem persists, replace the system board. System board failure (included ●...

  • Page 117: Recovering The Operating System

    It enables you to diagnose hardware issues, repair your computer, back up your files, or restore your computer to its factory state. 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 118: Wifi Power Cycle

    5. Press and hold the power button for 20 seconds to drain the flea power. 6. Install the battery. 7. Install the base cover. 8. Connect the power adapter to your computer. 9. Turn on your computer. NOTE: For more information about performing a hard reset, see the knowledge base article 000130881 www.dell.com/support. Troubleshooting...

  • Page 119: Chapter 6: Getting Help And Contacting Dell

    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 24. Self-help resources Self-help resources Resource location Information about Dell products and services www.dell.com My Dell app...

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