| Symptom | Likely Cause | Check This Signal | | :--- | :--- | :--- | | | Standby Failure | 3.3VSB / RSMRST# | | Fan spins for 1s, stops | Short Circuit | PSON# Toggle / Overcurrent Protection | | Fans spin, Black Screen | Main Power OK, Reset Fail | PLTRST# / BIOS CS# | | Debug LED: CPU | VCORE Failure or Bent Pins | VCORE Voltage / VRM MOS | | Debug LED: RAM | Memory Voltage or Training | VDDQ / VTT / SPD Data |
This signal (Resume Reset) comes from the Super I/O to the PCH. If this isn't 3.3V, the PCH will never respond to the power button.
| Symptom | Likely Cause | Check This Signal | | :--- | :--- | :--- | | | Standby Failure | 3.3VSB / RSMRST# | | Fan spins for 1s, stops | Short Circuit | PSON# Toggle / Overcurrent Protection | | Fans spin, Black Screen | Main Power OK, Reset Fail | PLTRST# / BIOS CS# | | Debug LED: CPU | VCORE Failure or Bent Pins | VCORE Voltage / VRM MOS | | Debug LED: RAM | Memory Voltage or Training | VDDQ / VTT / SPD Data |
This signal (Resume Reset) comes from the Super I/O to the PCH. If this isn't 3.3V, the PCH will never respond to the power button. desktop motherboard power sequence pdf exclusive