Таки похоже на то, что вам

что это может быть?

Power Light State --- Blinking Amber
Initial state of light at power up.
Indicates system has power, but the POWER_GOOD signal is not yet active.
If the Hard Drive light is off, it is probable that the power supply needs to be replaced.
If the Hard Drive light on, it is probable that an onboard regulator or VRM has failed. Look at the diagnostic lights for further information.