Replacing the DIMMs

To replace the DIMMs, you need to locate them inside the controller module, and then follow the specific sequence of steps.

About this task

If you are replacing a DIMM, you need to remove it after you have unplugged the NVMEM battery from the controller module.


  1. Check the NVMEM LED on the controller module.
    You must perform a clean system shutdown before replacing system components to avoid losing unwritten data in the nonvolatile memory (NVMEM). The LED is located on the back of the controller module. Look for the following icon:

  2. If the NVMEM LED is not flashing, there is no content in the NVMEM; you can skip the following steps and proceed to the next task in this procedure.
  3. If the NVMEM LED is flashing, there is data in the NVMEM and you must disconnect the battery to clear the memory:
    1. Locate the battery, press the clip on the face of the battery plug to release the lock clip from the plug socket, and then unplug the battery cable from the socket.
    2. Confirm that the NVMEM LED is no longer lit.
    3. Reconnect the battery connector.
  4. Return to 2 of this procedure to recheck the NVMEM LED.
  5. Locate the DIMMs on your controller module.
    Note: Each system memory DIMM has an LED located on the board next to each DIMM slot. The LED for the faulty blinks every two seconds.
  6. Note the orientation of the DIMM in the socket so that you can insert the replacement DIMM in the proper orientation.
  7. Eject the DIMM from its slot by slowly pushing apart the two DIMM ejector tabs on either side of the DIMM, and then slide the DIMM out of the slot.
    Attention: Carefully hold the DIMM by the edges to avoid pressure on the components on the DIMM circuit board.
    The number and placement of system DIMMs depends on the model of your system.

    The following illustration shows the location of system DIMMs:

  8. Remove the replacement DIMM from the antistatic shipping bag, hold the DIMM by the corners, and align it to the slot.
    The notch among the pins on the DIMM should line up with the tab in the socket.
  9. Make sure that the DIMM ejector tabs on the connector are in the open position, and then insert the DIMM squarely into the slot.
    The DIMM fits tightly in the slot, but should go in easily. If not, realign the DIMM with the slot and reinsert it.
    Attention: Visually inspect the DIMM to verify that it is evenly aligned and fully inserted into the slot.
  10. Push carefully, but firmly, on the top edge of the DIMM until the ejector tabs snap into place over the notches at the ends of the DIMM.
  11. Locate the NVMEM battery plug socket, and then squeeze the clip on the face of the battery cable plug to insert it into the socket.
    Make sure that the plug locks down onto the controller module.
  12. Close the controller module cover.