Dell OptiPlex 7480 All-In-One Service Manual page 63

11. SIO-power cable connector
12. Audio-board cable connector
13. Microphone-module cable connector
14. Speaker cable connector
15. Coin-cell battery
16. Power-button cable connector
17. Display cable connector
18. M.2 WLAN connector
19. PSU-fan cable connector
20. Touchscreen cable connector
21. Processor
The following image indicates the location of the system board and provides a visual representation of the removal procedure.
Removing and installing components 63