: The power supply (PSU) provides 5V standby power immediately upon being plugged in.
A concise, structured report describing the typical desktop motherboard power‑up and power‑down sequence, key signals, timing, and troubleshooting notes. Use this for diagnostics, firmware/BIOS development, or hardware repair. desktop motherboard power sequence pdf
Typically suggests a failure in the Southbridge/PCH or its clock section. Missing CPU Power Good: : The power supply (PSU) provides 5V standby