Dell OptiPlex 390 (Mid 2011) - Manual (Page 4)

Small Form Factor — Front And Back View
Figure 4. Front And Back View Of Small Form Factor
1. optical drive
2. optical drive eject button
3. power button
4. USB 2.0 connectors (2)
5. microphone connector
6. headphone connector
7. diagnostic lights (4)
8. hard-drive activity light 9. padlock ring
10. security cable slot
11. power cable connector
12. power-supply diagnostic button
13. power-supply diagnostic light
14. back panel connectors
15. expansion card slots (2)
4