Hi, i have intel mac mini and i usually shut it down when im not using it. When first plugging the mac mini, the fan will goes on, and while the fan is turning, i can't turn on my mac mini until the fan stop turning. What make me confuse is, sometimes the fan turning for about 2 seconds only, but sometime it can take about 6 minutes. So i have to wait for 6 minutes before i can turn on my mac mini.. What drives the time the fan have to on?