On Tue, Mar 16, 2010 at 1:04 AM, Jonathon Kuo <[email protected]> wrote:
> On Mar 15, 2010, at 8:25 PM, Macs R We wrote: >> >> On Mar 15, 2010, at 4:29 PM, Jonathon Kuo wrote: >> >>> We have a 2007 intel Mac mini that shut itself down due to overheating. >>> Now, as soon as power is connected to it, the fan runs at high speed. The >>> power button does nothing, the mini remains off. Is there some sort of >>> 'hardware reset' button to get this running again? >> >> The SMC is reset by disconnecting everything including power, then waiting >> 30 seconds. Presumably, you've already done that without even meaning to. >> >> I see nothing in the repair manual about the presence of any temperature >> sensors. If your Mini really did shut itself down due to temperature >> issues, it was not gracefully, and therefore starting it back up may not go >> easily. > > I've never heard of a system that didn't have overtemp protection. The > MacBooks, MacPros and iMacs have it, but not the minis? When the temp comes > back to normal, so does the system, in theory. I'm assuming that there's some > hidden reset button inside the case somewhere that's gotta get pushed, which > is why the fan is stuck on high. Just trying to think positive... Overtemp protection just shuts things down when a certain limit is exceeded at a sensor. In some situations this is not enough. In a typical machine room when the A/C fails temps continue to rise as systems start to fail so by the time you realize there is a problem it is too late. Add to that typical accumulations of dust on the cooling surfaces and you may find that peak temps in the places that matter occur after the power has been removed. We often see failed components after A/C failures in our small machine room. I suspect that (since the most useful place for a temp sensor is near the component you want to protect) that many of these failures are actually the temp sensor itself reporting bogus values (hence things like fan running at high speed) after a temp spike, but the end result is all too often system board needing replacement. -- George N. White III <[email protected]> Head of St. Margarets Bay, Nova Scotia _______________________________________________ MacOSX-talk mailing list [email protected] http://www.omnigroup.com/mailman/listinfo/macosx-talk
