Originally Posted By: JoBoy
...my Mac Pro showed a flashing white light above the On/Off button instead of the normal steady light. I am able to shut the off the flashing light by holding the button down for a few seconds.

The symptoms described might point to POST signaling, which can manifest as Power light blinking. If true, the number of blinks in the repeating series indicates the underlying issue, which may still require a visit to the Genius Bar.

alternaut • moderator