Dead Motherboard Diagnosis - No Post

ID: 213049

Description: 1. Diagnosing a Faulty Motherboard: This guide ...

Steps:

  1. Perform these steps with only the power supply connected (ATX 24-pin and 12V CPU connectors), no CPU or RAM installed.
  2. Disconnect all peripherals, drives, and expansion cards.
  3. Connect PSU to motherboard with ATX 24-pin and 12V CPU power connectors only..
  4. Use a known-good PSU if possible.
  5. Verify +5VSB presence at ATX_PWR pin 9.
  6. Confirm motherboard LEDs (if any) light up indicating standby power.
  7. Short PS_ON (pin 16 on ATX 24-pin) to ground to start PSU.
  8. Check if PSU powers up (+12V, +5V, +3.3V rails active).
  9. Look for any signs of life: LEDs, fan spin, beep codes.
  10. No signs indicate power or board failure.
  11. Measure voltage on key rails:
  12. +5V main rail +12V CPU rail +3.3V rail
  13. Absence or incorrect voltages indicate PSU or motherboard power circuit issues.
  14. If power rails are good but no POST, add CPU and RAM for further testing. If no standby power, check PSU and motherboard power input circuits.
Back