DIMMs of the same capacity are available with different rank classifications and cannot be mixed in the server module. For example, you cannot install a combination of quad-rank and dual-rank 16-GByte DIMMs. Refer to the label on the DIMM for capacity and rank information. See DIMM Configuration Guidelines.
Align the DIMM notch with the key in the connector, as in panel 3. This action ensures that the DIMM is oriented correctly. Panel 2 shows an incorrect alignment.
If the DIMM does not easily seat into the connector, verify that the orientation of the DIMM is correct. Never apply excessive force.
Verify a replacement DIMM. See Clear the Fault and Verify the Functionality of the Replacement DIMM.
Verify additional memory. See Verify DIMM Functionality.