Cooling fan overdrive

[Stig Eliassen]

First time I've ever experienced this. The cooling fan(s?) in my G5 were in overdrive mode when I walked in. They must've been going full speed, because I've never heard anything remotely close to this. The screen was frozen, and keyboard and trackball didn't work. I had to hold the power button to shut it down.

What on earth can cause this? There's no change in terms of temperature in that room, so I don't get it?

[Drew Mazurek]

I think it's a "protection mode" of sorts. When the fan control unit isn't getting instructions from the OS as to temperature, it just goes full on to be safe. I've seen it a time or two during freezes.

[Stig Eliassen]

Originally Posted by dmazurek

I think it's a "protection mode" of sorts. When the fan control unit isn't getting instructions from the OS as to temperature, it just goes full on to be safe. I've seen it a time or two during freezes.

Ah, I see. That's way more positive than what I had in mind. I'll go with your theory. Thank you.

[Cliffy_Boy]

If its a dual G5, you probably need a processor calibration which can only be done at an Apple store.

[Stig Eliassen]

Originally Posted by Cliffy_Boy

If its a dual G5, you probably need a processor calibration which can only be done at an Apple store.

How so? It seems like it's back to normal now.

[Cliffy_Boy]

A reboot cures it for a few days.If it happens again and you are on a dual G5, its a thermal something or other and requires a calibration. Happened twice to me in 6 years.

[Stig Eliassen]

Originally Posted by Cliffy_Boy

A reboot cures it for a few days.If it happens again and you are on a dual G5, its a thermal something or other and requires a calibration. Happened twice to me in 6 years.

Ok, we'll see how this pans out. Thanks.