Note:
The system board might look slightly different from the illustration.
Figure 1. System board part locations
| 1 Cover presence switch connector (intrusion switch connector) | 2 Memory slot |
| 3 Memory slot | 4 Rear-fan-assembly connector |
| 5 Memory slot | 6 Memory slot |
| 7 Microprocessor fan connector | 8 Memory slot |
| 9 Memory slot | 10 Optical-drive fan connector 1 |
| 11 Optical-drive fan connector 2 | 12 Memory slot |
| 13 Memory slot | 14 Thermal-sensor connector |
| 15 4-pin power connector (for optical drive) | 16 Clear CMOS /Recovery jumper |
| 17 VROC connector | 18 Front panel input/output (FPIO) connector |
| 19 Memory fan connector 1 | 20 M.2 solid-state drive slot 2 |
| 21 M.2 solid-state drive slot 1 | 22 6-pin power connector (for graphics card) |
| 23 6-pin power connector (for graphics card) | 24 Internal-storage-drive activity indicator connector |
| 25 4-pin power connector (for storage drive) | 26 Front-fan-assembly connector |
| 27 Thunderbolt™ control connector | 28 SATA 2 connector |
| 29 SATA 3 connector | 30 SATA 6 connector |
| 31 SATA 1 connector | 32 SATA 4 connector |
| 33 Internal USB 3.0 connector 2 | 34 Internal USB 3.0 connector 1 |
| 35 SATA 5 connector | 36 Four-digit-diagnostics display connector |
| 37 eSATA/SATA 7 connector | 38 Internal USB 2.0 connector |
| 39 Trusted cryptography module (TCM) connector | 40 Power supply connector |
| 41 PCIe 3.0 x4 card slot | 42 PCI card slot |
| 43 PCIe 3.0 x16 card slot | 44 PCIe 3.0 x4 card slot |
| 45 PCIe 3.0 x16 card slot | 46 PCIe 3.0 x8 card slot |
| 47 Coin-cell battery | 48 Memory fan connector 2 |
| 49 Microprocessor | 50 Serial port (COM) connector |