When fault occurs on DIMMs that result in all DIMMs on the same branch being disabled, Oracle ILOM might not mark them as faulty or send diagnostic message, but only send one ereport:
ereport.memory.mrc.init-no-memory@/sys/blX/pY/mrZ
Where X is the blade slot number, Y is the processor, and Z is the DIMM memory branch.
Workaround
Use the Oracle ILOM Fault Manager to view information about active faults (fmadm faulty) to identify the mismatched DIMM pair.
Then replace the pair with a matched pair. If the fault isn't cleared automatically, you must manually clear it using the appropriate Oracle ILOM fmadm repair command as described in the Oracle ILOM documentation.