Which POST error code would indicate a problem with the power supply?

The reason the answer indicating the 5xx POST error codes is correct is that these codes are specifically associated with hardware failures, including power supply issues. When the computer performs its Power-On Self-Test (POST), it checks various components to ensure they are functioning correctly. If there is an anomaly detected in the power supply, it can significantly impact the system's ability to operate, and the BIOS will report this through specific error codes in the 500 range.

These codes help technicians quickly identify that the issue lies within the power supply or related components, allowing for efficient troubleshooting and repair. In contrast, other ranges like 1xx, 2xx, and 4xx typically indicate issues such as memory errors or specific peripheral malfunctions, not directly tied to power supply problems. Understanding these codes is crucial for diagnosing hardware issues effectively.