Dell Latitude 5421 Service Manual page 5

Removing the sensor board.......................................................................................................................................91
Installing the sensor board......................................................................................................................................... 91
Display hinges.....................................................................................................................................................................92
Removing the display hinges.................................................................................................................................... 92
Installing the display hinges.......................................................................................................................................93
Display back cover............................................................................................................................................................ 95
Removing the display back cover............................................................................................................................95
Installing the display back cover.............................................................................................................................. 96
Dummy SIM-card slot filler..............................................................................................................................................97
Removing the dummy SIM-card slot filler............................................................................................................. 97
Installing the dummy SIM-card slot filler............................................................................................................... 98
Palm-rest assembly.........................................................................................................................................................100
Removing the palm-rest assembly........................................................................................................................ 100
Installing the palm-rest assembly........................................................................................................................... 101
Chapter 3: Drivers and downloads.............................................................................................. 104
Downloading the drivers................................................................................................................................................ 104
Chapter 4: System setup........................................................................................................... 105
BIOS overview..................................................................................................................................................................105
Entering BIOS setup program.......................................................................................................................................105
Navigation keys................................................................................................................................................................105
One time boot menu....................................................................................................................................................... 106
System setup options..................................................................................................................................................... 106
Updating the BIOS........................................................................................................................................................... 116
Updating the BIOS in Windows............................................................................................................................... 116
Updating the BIOS in Linux and Ubuntu............................................................................................................... 117
Updating the BIOS using the USB drive in Windows......................................................................................... 117
Updating the BIOS from the F12 One-Time boot menu.................................................................................... 117
System and setup password..........................................................................................................................................118
Assigning a system setup password...................................................................................................................... 118
Deleting or changing an existing system setup password................................................................................ 119
Clearing CMOS settings................................................................................................................................................. 119
Clearing BIOS (System Setup) and System passwords.........................................................................................120
Chapter 5: Troubleshooting........................................................................................................ 121
Handling swollen Lithium-ion batteries....................................................................................................................... 121
Dell SupportAssist Pre-boot System Performance Check diagnostics.............................................................. 122
Running the SupportAssist Pre-Boot System Performance Check.............................................................. 122
Built-in self-test (BIST)..................................................................................................................................................122
M-BIST......................................................................................................................................................................... 122
LCD Power rail test (L-BIST)..................................................................................................................................123
LCD Built-in Self Test (BIST)..................................................................................................................................123
System diagnostic lights................................................................................................................................................ 124
Recovering the operating system................................................................................................................................125
Real-Time Clock (RTC Reset)...................................................................................................................................... 125
Backup media and recovery options........................................................................................................................... 125
WiFi power cycle..............................................................................................................................................................126
Drain residual flea power (perform hard reset)........................................................................................................126
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