Dell Precision 690 - Manual (Page 114)

If you insert the module correctly, the securing clips snap into the cutouts at each end of the module.
11. Ensure that memory riser card 3 is above system-board connector DIMM_3 and memory riser card 4 is above system-board connector DIMM_4.
Align the notch on the bottom of each riser card with the crossbar in each system-board connector.
12. Insert the riser cards into the connectors until both riser cards snap into position.
13. Connect the power cables back into memory riser cards 3 and 4.
14. Ensure that memory riser card 1 is above system-board connector DIMM_1 and memory riser card 2 is above system-board connector DIMM_2.
Align the notch on the bottom of each riser card with the crossbar in each system-board connector.
15. Insert the riser cards into the connectors until both riser cards snap into position.
16. Connect the power cables back into memory riser cards 1 and 2.
1 memory riser cards 1 and 2
2 memory riser cards 3 and 4
NOTE: If a memory-riser power cable is not plugged in, the system will not boot.
NOTE: If a memory-riser power cable is not plugged in, the system will not boot.
1 memory shroud