Inspiron 7405 2n1 Service Manual Regulatory Model: P126G Regulatory Type: P126G001 June 2020 Rev.
Notes, cautions, and warnings NOTE: A NOTE indicates important information that helps you make better use of your product. CAUTION: A CAUTION indicates either potential damage to hardware or loss of data and tells you how to avoid the problem. WARNING: 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.
Contents Chapter 1: Working inside your computer..........................................................................................5 Before working inside your computer................................................................................................................................. 5 Safety instructions................................................................................................................................................................
Installing the fan.............................................................................................................................................................36 I/O board.............................................................................................................................................................................. 36 Removing the I/O board.............................................................................................................................
1 Working inside your computer Before working inside your computer About this task NOTE: The images in this document may differ from your computer depending on the configuration you ordered. Steps 1. Save and close all open files and exit all open applications. 2. Shut down your computer. Click Start > Power > Shut down. NOTE: If you are using a different operating system, see the documentation of your operating system for shut-down instructions. 3.
CAUTION: Press and eject any installed card from the media-card reader. NOTE: The color of your computer and certain components may appear differently than shown in this document. Electrostatic discharge—ESD protection ESD is a major concern when you handle electronic components, especially sensitive components such as expansion cards, processors, memory DIMMs, and system boards.
• • • • Insulator Elements – It is critical to keep ESD sensitive devices, such as plastic heat sink casings, away from internal parts that are insulators and often highly charged. Working Environment – Before deploying the ESD Field Service kit, assess the situation at the customer location. For example, deploying the kit for a server environment is different than for a desktop or portable environment.
2 Removing and installing components Recommended tools The procedures in this document may require the following tools: • • Phillips screwdrivers #0 and #1 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. This is to ensure that the correct number of screws and correct screw type is restored when the component is replaced. NOTE: Some computers have magnetic surfaces.
Table 1. Screw list (continued) Component Secured to Screw type Quantity Display hinges Palm-rest and keyboard assembly M2.
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.
Base cover Removing the base cover Prerequisites 1. Follow the procedure in Before working inside your computer. 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
Steps 1. Remove the six screws (M2x4) that secure the base cover to the palm-rest and keyboard assembly. 2. Loosen the three captive screws that secure the base cover to the palm-rest and keyboard assembly. NOTE: Upon loosening the three captive screws, the base cover will pop up creating a gap between the base cover and the palm-rest assembly. 3. Starting from the top-right corner, use a plastic scribe to pry the base cover to release the base cover from the palm-rest and keyboard assembly.
Removing and installing components
Steps 1. Connect the battery cable to the system board. 2. Adhere the tape that secures the battery cable to the system board. 3. Align the screw holes on the base cover with the screw holes on the palm-rest and keyboard assembly, and then snap the base cover into place. 4. Replace the six screws (M2x4) that secure the base cover to the palm-rest and keyboard assembly. 5. Tighten the three captive screws that secure the base cover to the palm-rest and keyboard assembly. Next steps 1.
Steps 1. Peel the tape that secures the battery cable to the system board (applicable only if not peeled earlier). 2. Disconnect the battery cable from the system board (applicable only if not disconnected earlier). 3. Remove the five screws (M2x3) that secure the battery to the palm-rest and keyboard assembly. 4. Lift the battery off the palm-rest and keyboard assembly.
Steps 1. Using the alignment posts, place the battery on the palm-rest and keyboard assembly. 2. Replace the five screws (M2x3) that secure the battery to the palm-rest and keyboard assembly. 3. Connect the battery cable to the system board. 4. Adhere the tape that secures the battery cable to the system board. Next steps 1. Install the base cover. 2. Follow the procedure in After working inside your computer. Coin-cell battery Removing the coin-cell battery Prerequisites 1.
Steps 1. Disconnect the coin-cell battery from the I/O board. 2. Remove the coin-cell battery cable from the routing guide on the fan. 3. Using a plastic scribe, peel the coin-cell battery off the slot on the palm-rest and keyboard assembly. Installing the coin-cell battery Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.
Steps 1. Adhere the coin-cell battery to the slot on the palm-rest and keyboard assembly. 2. Lift the speaker cable and route the coin-cell battery cable through the routing guide on the fan. 3. Connect the coin-cell battery cable to the I/O board. Next steps 1. Install the base cover. 2. Follow the procedure in After working inside your computer. Memory modules Removing the memory modules Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the base cover.
Steps 1. Lift the flap to access the memory module. 2. Use your fingertips to carefully spread apart the securing-clips on each end of the memory-module slot until the memory module pops up. 3. Slide and remove the memory module from the memory-module slot. NOTE: Repeat step 2 to step 3 to remove any other memory modules installed in your computer. Installing the memory modules Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.
Steps 1. Lift the flap to access the memory-module slot. 2. Align the notch on the memory module with the tab on the memory-module slot. 3. Slide the memory module firmly at an angle, into the memory-module slot. 4. Press the memory module down until it clicks into place. NOTE: If you do not hear the click, remove the memory module and reinstall it. NOTE: Repeat step 2 to step 4 to install any other memory modules in your computer. Next steps 1. Install the base cover. 2.
Speakers Removing the speakers Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the base cover. About this task The following image indicates the location of the speakers and provides a visual representation of the removal procedure. Steps 1. Disconnect the speaker cable from the system board. 2. Note the speaker cable routing, and remove the speaker cable from the routing guides on the palm-rest and keyboard assembly. 3.
Steps 1. Using the alignment posts and rubber grommets, place the speakers on the slots of the palm-rest and keyboard assembly. 2. Route the speaker cable through the routing guides on the palm-rest and keyboard assembly. 3. Connect the speaker cable to the system board. Next steps 1. Install the base cover. 2. Follow the procedure in After working inside your computer. Heat sink Removing the heat sink Prerequisites 1. Follow the procedure in Before working inside your computer.
Steps 1. In reverse sequential order (as indicated on the heat sink), loosen the seven captive screws that secure the heat sink to the system board. 2. Lift the heat sink off the system board. Installing the heat sink Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. CAUTION: Incorrect alignment of the heat sink can damage the system board and processor.
Steps 1. Align the screw holes on the heat sink with the screw holes on the system board. 2. In sequential order (as indicated on the heat sink), tighten the seven captive screws that secure the heat sink to the system board. Next steps 1. Install the base cover. 2. Follow the procedure in After working inside your computer. Power-adapter port Removing the power-adapter port Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the base cover.
Steps 1. Remove the three screws (M2.5x5) that secure the right display-hinge to the palm-rest and keyboard assembly. 2. Open the right display-hinge at an angle of 90 degrees. 3. Peel the tape that secures the power-adapter port cable to the system board. 4. Disconnect the power-adapter port cable from the system board. 5. Remove the screw (M2x3) that secures the power-adapter port to the palm-rest and keyboard assembly. 6.
Steps 1. Place the power-adapter port into the slot on the palm-rest and keyboard assembly. 2. Replace the screw (M2x3) that secures the power-adapter port to the palm-rest and keyboard assembly. 3. Route the power-adapter port cable through the routing guide on the palm-rest and keyboard assembly. 4. Connect the power-adapter port cable to the system board. 5. Adhere the tape that secures the power-adapter port cable to the system board. 6. Close the right display-hinge. 7. Replace the three screws (M2.
Steps 1. Remove the three screws (M2x2) that secure the touchpad bracket to the palm-rest and keyboard assembly. 2. Open the latch, and disconnect the touchpad cable from the touchpad. 3. Peel the tape that secures the touchpad to the palm-rest and keyboard assembly. 4. Remove the two screws (M2x2) that secure the touchpad to the palm-rest and keyboard assembly. 5. Slide and lift the touchpad off the palm-rest and keyboard assembly.
Steps 1. Slide the touchpad into the slot on the palm-rest and keyboard assembly. 2. Replace the two screws (M2x2) that secure the touchpad to the palm-rest and keyboard assembly. 3. Adhere the tape that secures the touchpad to the palm-rest and keyboard assembly. 4. Slide the touchpad cable into the connector on the touchpad and close the latch to secure the cable. 5. Place the touchpad bracket into the slot on the palm-rest and keyboard assembly. 6.
Steps 1. Remove the screw (M2x3) that secures the solid-state drive thermal bracket to the palm-rest and keyboard assembly. 2. Lift the solid-state drive thermal bracket off the palm-rest and keyboard assembly. 3. Remove the screw (M2x3) that secures the solid-state drive to the solid-state drive bracket. 4. Slide and remove the solid-state drive from the solid-state drive slot. Installing the M.
The following image indicates the location of the M.2 2230 solid-state drive and provides a visual representation of the installation procedure.
Steps 1. Remove the screw (M1.6x2.5) that secures the solid-state drive bracket to the palm-rest and keyboard assembly. 2. Turn the solid-state drive bracket at an angle of 180 degrees. 3. Insert the solid-state drive bracket into the other solid-state drive bracket slot on the palm-rest and keyboard assembly. 4. Replace the screw (M1.6x2.5) that secures the solid-state drive bracket to the palm-rest and keyboard assembly. 5.
Steps 1. Remove the screw (M2x3) that secures the solid-state drive thermal bracket to the palm-rest and keyboard assembly. 2. Lift the solid-state drive thermal bracket off the palm-rest and keyboard assembly. 3. Remove the screw (M2x3) that secures the solid-state drive to the solid-state drive bracket. 4. Slide and remove the solid-state drive from the solid-state drive slot. Installing the M.
The following image indicates the location of the M.2 2280 solid-state drive and provides a visual representation of the installation procedure. NOTE: Perform step 1 to step 3 if you are replacing the M.2 2230 solid-state drive with an M.2 2280 solid-state drive.
Steps 1. Remove the screw (M1.6x2.5) that secures the solid-state drive bracket to the palm-rest and keyboard assembly. 2. Turn the solid-state drive bracket at an angle of 180 degrees. 3. Insert the solid-state drive bracket into the other solid-state drive bracket slot on the palm-rest and keyboard assembly. 4. Replace the screw (M1.6x2.5) that secures the solid-state drive bracket to the palm-rest and keyboard assembly. 5.
3. Lift the fan off the palm-rest and keyboard assembly. Installing the 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 fan and provides a visual representation of the installation procedure. Steps 1. Using the alignment posts, place the fan on the palm-rest and keyboard assembly. 2.
About this task The following image indicates the location of the I/O-board and provides a visual representation of the removal procedure. Steps 1. Remove the two screws (M2.5x5) that secure the left display hinge to the palm-rest and keyboard assembly. 2. Open the left-display hinge at an angle of 90 degrees. 3. Peel the tape that secures the I/O-board cable to the I/O board. 4. Open the latch, and disconnect the I/O-board cable from the I/O board. 5.
Steps 1. Slide the I/O board into the slots on the palm-rest and keyboard assembly. 2. Align the screw hole on the I/O board with the screw hole on the palm-rest and keyboard assembly. 3. Replace the screw (M2x3) that secures the I/O board to the palm-rest and keyboard assembly. 4. Connect the I/O-board cable to the connector on the I/O board and close the latch to secure the cable. 5. Adhere the tape that secures the I/O-board cable to the I/O board. 6.
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. Steps 1. Remove the two screws (M2x3) that secure the power-button bracket to the palm-rest and keyboard assembly. 2. Lift the power-button bracket off the palm-rest and keyboard assembly. 3. Peel the tape that secures the I/O-board cable to the I/O board. 4. Open the latch, and disconnect the I/O-board cable from the I/O board. 5.
Steps 1. Align and place the power button, along with its cable, on the slot of the palm-rest and keyboard assembly. 2. Slide the power-button cable into the connector on the fingerprint reader-board and close the latch to secure the cable. 3. Connect the fingerprint reader-cable to the connector on the I/O board and close the latch to secure the cable. 4. Connect the I/O-board cable to the connector on the I/O board and close the latch to secure the cable. 5.
Removing and installing components 41
Steps 1. Peel the tape that secures the display cable to the system board. 2. Open the latch, and disconnect the display cable from the system board. 3. Remove the two screws (M2.5x5) that secure the left-display hinges to the palm-rest and keyboard assembly. 4. Remove the three screws (M2.5x5) that secure the right-display hinges to the palm-rest and keyboard assembly.
5. Lift at an angle and slide the display assembly off the palm-rest and keyboard 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 image indicates the location of the display assembly and provides a visual representation of the installation procedure.
Steps 1. Slide the display assembly at an angle, and place the display assembly on the palm-rest and keyboard assembly. 2. Replace the two screws (M2.5x5) that secure the left-display hinge to the palm-rest and keyboard assembly. 3. Replace the three screws (M2.5x5) that secure the right-display hinge to the palm-rest and keyboard assembly. 4. Connect the display-cable connector to the system board and close the latch to secure the cable. 5.
System board Removing the system board Prerequisites 1. 2. 3. 4. 5. 6. 7. Follow the procedure in Before working inside your computer. Remove the base cover. Remove the battery. Remove the coin-cell battery. Remove the memory modules. Remove the M.2 2230 solid-state drive or M.2 2280 solid-state drive, as applicable. Remove the heat sink. About this task The following image indicates the connectors on your system board. Figure 1. System-board connectors 1. 3. 5. 7.
Steps 1. Remove the three screws (M2.5x5) that secure the right-display hinge to the palm-rest and keyboard assembly.. 2. Open the hinge at an angle of 90 degrees. 3. Peel the tape that secures the USB Type-C port bracket to the system board. 4. Disconnect the fan cable from the system board.
5. Peel the tape that secures the I/O-board cable to the system board. 6. Open the latch, and disconnect the I/O-board cable from the system board. 7. Disconnect the speaker cable from the system board. 8. Open the latch, and disconnect the touchpad cable from the system board. 9. Open the latch, and disconnect the keyboard cable from the system board. 10. Remove the two screws (M2x3) that secure the USB Type-C bracket to the system board. 11.
Steps 1. Align and place the system board on the palm-rest and keyboard assembly. 2. Replace the two screws (M2x2) that secure the system board to the palm-rest and keyboard assembly. 3. Connect the display cable to the connector on the system board and close the latch to secure the cable. 4. Adhere the tape that secures the display cable to the system board.
5. Connect the power-adapter port cable to the connector on the system board. 6. Align the screw holes on the USB Type-C port bracket with the screw holes on the system board. 7. Adhere the tape that secures the USB Type-C port bracket to the system board. 8. Replace the two screws (M2x3) that secure the USB Type-C port bracket to the system board. 9. Connect the keyboard cable to the connector on the system board and close the latch to secure the cable. 10.
Steps After performing the steps in the pre-requisites, you are left with the palm-rest and keyboard assembly. Installing the palm-rest and keyboard assembly 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 palm-rest and keyboard assembly and provides a visual representation of the installation procedure.
Steps Place the palm-rest and keyboard assembly on a clean and flat surface. Next steps 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Install the system board. Install the display assembly. Install the power-button board. Install the touchpad. Install the power-adapter port. Install the fan. Install the heat sink. Install the speakers. Install the I/O board. Install the M.2 2230 solid-state drive or M.2 2280 solid-state drive, as applicable. Install the memory modules. Install the coin-cell battery.
3 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.
4 System 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.
• • Removable Drive (if available) STXXXX Drive (if available) NOTE: XXX denotes the SATA drive number. • • • Optical Drive (if available) SATA Hard Drive (if available) Diagnostics The boot sequence screen also displays the option to access the System Setup screen. One time boot menu To enter one time boot menu, turn on your computer, and then press F2 immediately. NOTE: It is recommended to shutdown the computer if it is on.
Table 3. System setup options—Main menu (continued) Main Keyboard Type Displays the type of keyboard installed on the computer. Table 4. System setup options—Advanced menu Advanced PowerNow! Enable Enables or disables the dynamic frequency scaling and powersaving technology for the AMD processor. Default: Enabled Virtualization Enables or disables the Virtualization technology. Default: Enabled Integrated NIC Enables or disables the on-board LAN controller.
Table 4. System setup options—Advanced menu (continued) Advanced Keyboard Backlight with Battery Selects the timeout value for the keyboard backlight when the computer is running on battery power. Default: 1 minute Express Charge Selects the battery charge mode. Default: Express Charge Battery Health Displays the battery health. Camera Enables or disables the camera. Default: Disabled Battery Charge Configuration Set the battery charge settings with a preselected custom charge start and stop.
Table 5. System setup options—Security menu (continued) Security Admin Password Allows you to set the administrator password. The administrator password controls access to the system setup utility. System Password Allows you to set the system password. The system password controls access to the computer at boot. HDD2 password Allows you to set, change, or delete the hard-disk drive password. Password Change Allows you to permit or deny system password or HDD password changes.
Table 6. System setup options—Boot menu (continued) Boot Attempt Legacy Boot Enables or disables legacy boot. Default: Disabled File Browser Add Boot Option Allows you to add the boot options. Table 7. System setup options—Exit menu Exit Exit Saving Changes Allows you to exit system setup and save your changes. Save Change Without Exit Allows you to save your changes without exiting the BIOS setup. Exit Discarding Changes Allows you to exit the BIOS setup without saving the changes.
5 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. It allows you to: • • • • • • Run tests automatically or in an interactive mode.
Table 9. LED codes Diagnostic light codes Problem description 2,1 Processor failure 2,2 System board: BIOS or ROM (Read-Only Memory) failure 2,3 No memory or RAM (Random-Access Memory) detected 2,4 Memory or RAM (Random-Access Memory) failure 2,5 Invalid memory installed 2,6 System-board or chipset error 2,7 Display failure 2,8 LCD power rail failure.
7. Click Download to download the latest version of the BIOS for your computer. 8. After the download is complete, navigate to the folder where you saved the BIOS update file. 9. Double-click the BIOS update file icon and follow the instructions on the screen. Flashing BIOS (USB key) Steps 1. Follow the procedure from step 1 to step 7 in "Flashing the BIOS" to download the latest BIOS setup program file. 2. Create a bootable USB drive. For more information see the knowledge base article SLN143196 at www.
3. Press and hold the power button for 15 seconds to drain the flea power. 4. Install the base cover. 5. Turn on your computer.
6 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 10. 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. Online help for operating system www.dell.com/support/windows www.dell.
