When a modern Dell PowerEdge R760 server experiences a No-POST condition immediately following a memory capacity expansion, the root cause is almost exclusively tied to a physical installation error or an unvalidated configuration layout. Modern Intel Xeon Scalable processor architectures implement complex, multi-channel memory controllers that operate under rigid DIMM population matrices and balanced routing rules. If newly added modules are inserted into incorrect slots or violate the strict symmetrical configuration criteria mandated by the system architecture, the memory controller will fail to pass early hardware training phases, preventing the server from completing POST. To remediate this specific behavior, the technician must verify the exact DIMM population rules outlined in the technical documentation to ensure proper channel alignment. Following validation, a physical reseating of the memory modules must be completed to rule out minor electrical contact resistance or structural alignment faults inside the slots. Study Guide References: Troubleshooting; Memory Subsystem Architecture; POST Failure Isolation and Memory Population Rules.