Dell OptiPlex Small Form Factor Plus 7020 Owner's Manual page 108

4. UDIMM slots
From the left (a>b>c>d):
DIMM 3
DIMM 1
DIMM 4
DIMM 2
5. Hard-drive data connector (SATA-1)
6. M.2 2230 solid-state drive slot (M.2 PCIe SSD-1)
7. Power-button connector (PWR SW)
8. SD-card reader slot (SD CARD)
9. M.2 WLAN slot (M.2 WLAN)
10. M.2 2280 solid-state drive slot (M.2 PCIe SSD-2)
11. Chassis-fan connector (FAN SYS)
12. System power connector (ATX SYS)
13. Internal speaker (INT SPKR)
14. Hard-drive data connector (SATA-0)
15. Optical-drive/hard-drive data connector (SATA-3)
16. SATA power connector (SATA PWR)
17. PCIe x16 slot (SLOT 2)
18. PCIe x4 slot (SLOT 1)
19. M.2 2230 solid-state drive slot (M.2 PCIe SSD-0)
20. Optional Type-C connector (TYPE-C)
21. Coin-cell battery socket (RTC)
22. Optional Video connector (VIDEO)
23. Processor socket
24. Serial PS2 module connector (KB MS, SERIAL)
The following images indicate the location of the system board and provide a visual representation of the removal procedure.
108 Removing and installing Field Replaceable Units (FRUs)