Service Manual
Table Of Contents
- Latitude 3420 Service Manual
- Working inside your computer
- Removing and installing components
- Recommended tools
- Screw List
- Major components of your system
- MicroSD-card
- SIM card tray
- Base cover
- Battery cable
- Battery
- Memory module
- M.2 solid-state drive thermal plate
- M.2 solid-state drive conversion bracket
- M.2 solid-state drive
- Hard-disk drive
- WLAN card
- WWAN card
- I/O cable
- Display assembly
- System fan
- Heatsink assembly
- Power adapter port
- Coin-cell battery
- USB cable
- Ethernet port
- I/O board
- Power-button board
- System board
- Speakers
- Touchpad
- WWAN I/O board
- Palmrest assembly
- Display bezel
- Display panel
- Camera
- Display cable
- Display back-cover
- Drivers and downloads
- System setup
- Troubleshooting
- Built-in self-test (BIST)
- LCD Built-in Self Test (BIST)
- Dell SupportAssist Pre-boot System Performance Check diagnostics
- Diagnostic LED behavior
- Diagnostic error messages
- System error messages
- Recovering the operating system
- Real-Time Clock (RTC Reset)
- Flashing the BIOS
- Backup media and recovery options
- WiFi power cycle
- Flea power release
- Getting help and contacting Dell
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: Before you change BIOS Setup program, it is recommended that you write down the BIOS Setup program screen
information for future reference.
Use the BIOS Setup program for the following purposes:
● Get information about the hardware installed in your computer, such as the amount of RAM and the size of the hard drive.
● Change the system configuration information.
● Set or change a user-selectable option, such as the user password, type of hard drive installed, and enabling or disabling
base devices.
Topics:
• Boot menu
• Boot Sequence
• Navigation keys
• System setup options
• Updating the BIOS in Windows
• System and setup password
Boot menu
To initiate a one-time boot menu with a list of the valid boot devices for the system, press <F12> when the Dell logo is displayed.
Diagnostics and BIOS Setup options are also in this menu. The devices that are listed on the boot menu depend on the bootable
devices in the system. This menu is useful when you are attempting to boot to a particular device or to bring up the diagnostics
for the system. Using the boot menu, do not change the boot order that is stored in the BIOS.
The options are:
● Legacy External Device Boot
○ Onboard NIC
● UEFI Boot:
○ UEFI: TOSHIBA MQ01ACF050
● Other Options:
○ BIOS Setup
○ Device Configuration
○ BIOS Flash Update
○ Diagnostics
○ Intel (R) Management Engine BIOS Extension (MEBx)
○ Change Boot Mode Settings
Boot Sequence
Boot sequence enables 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:
● Access System Setup by pressing F2 key
● 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:
4
96 System setup