- Notes, cautions, and warnings
- Working inside your computer
- Removing and installing components
- Recommended tools
- Screw list
- Major components of OptiPlex 7400 All-in-One
- Stand
- Cable cover—optional
- Back cover
- Memory module
- System-board shield
- Solid-state drive
- Removing the M.2 2230 solid-state drive-slot 1
- Installing the M.2 2230 solid-state drive-slot 1
- Removing the M.2 2280 solid-state drive-slot 1
- Installing the M.2 2280 solid-state drive-slot 1
- Removing the M.2 2230 solid-state drive-slot 2
- Installing the M.2 2230 solid-state drive-slot 2
- Removing the M.2 2280 solid-state drive-slot 2
- Installing the M.2 2280 solid-state drive-slot 2
- System fan
- Coin-cell battery
- Wireless card
- Camera assembly
- Bottom cover
- Power-supply unit
- Power-supply fan
- Heat sink
- Processor
- Rear-I/O bracket
- System board
- Speakers
- Power-button board
- Microphones
- Side I/O-board
- Audio board
- Antenna modules
- Display panel
- Middle frame
- Drivers and downloads
- BIOS Setup
- Troubleshooting
- Dell SupportAssist Pre-boot System Performance Check diagnostics
- Display built-in self test
- Power-Supply Unit Built-in Self-Test
- System-diagnostic lights
- Recovering the operating system
- Real Time Clock—RTC reset
- Downloading and installing the Dell OSD application
- Backup media and recovery options
- Wi-Fi power cycle
- Getting help and contacting Dell