The power supply for a user’s gaming PC fails.

CompTIA A+ repeatedly highlights that modern motherboards require two power connectors:

The 24-pin ATX main power connector

The 4-pin or 8-pin CPU power connector (EPS connector)

If the CPU power connector is missing, the system will not POST, even though other components appear to have power. This is a very common mistake after replacing PSUs and is specifically noted in CompTIA materials as a frequent cause of “no boot” scenarios.

Insufficient wattage usually causes instability, not a total failure to start. RAM is unrelated to powering on. Redundant PSUs are used in servers, not gaming PCs.

Thus, the missing CPU power connector is the correct diagnosis and matches A+ hardware troubleshooting guidelines.