Be sure the memory meets the server
requirements and is installed as required by the server. Some
servers may require that memory banks be populated fully or that
all memory within a memory bank must be the same size, type, and
speed. To determine if the memory is installed properly, see the
server documentation.
Check any server LEDs that correspond to
memory slots.
If you are unsure which DIMM has failed,
test each bank of DIMMs by removing all other DIMMs. Then, isolate
the failed DIMM by switching each DIMM in a bank with a known
working DIMM.