Dell Precision Workstation 690 User Manual page 116

3. Loosen the captive thumbscrews that secure the memory shroud and lift it away from the computer.
CAUTION: Fully-buffered memory modules may become very hot during normal operation. Ensure that memory modules have had sufficient time
to cool before you touch them.
4. Disconnect the power cables from memory riser cards 1 and 2.
1 power connectors (4)
2 memory module connectors (4)
3 securing clips (2)
5. Grasp the memory riser card 1 at each corner and lift memory riser card 1 and attached card 2 from the DIMM_1 and DIMM_2 memory module connectors
on the system board.
If a card is difficult to remove, gently ease it back and forth to remove it from the connector.
1 memory riser cards 1 and 2
2 memory riser cards 3 and 4
6. Disconnect the power cables from memory riser cards 3 and 4.