The computer is completely disconnected from the power source (wall outlet unplugged).
If a motherboard won't turn on, check these signals in order: : Is the standby light on? RTCRST : Is the CMOS battery above 3V? RSMRST : Is the SIO chip signaling the PCH to wake up? desktop motherboard power sequence pdf
SLP_S4# ───────────────────────────────────────┐ (Enables DDR) └──────────────────── The computer is completely disconnected from the power