Dell Inspiron 24 5421 Owner's Manual page 100

11. Install the retractable-camera
12. Install the fan.
13. Install the media-card
14. Install the system-board
15. Install the hard drive.
16. Install the I/O cover.
17. Install the back cover.
18. Install the stand.
19. Follow the procedure in
100 Removing and installing Field Replaceable Units (FRUs)
assembly.
reader.
shield.
After working inside your computer.