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Power PC G5 fan noise

M

mattdunlap2000

macrumors newbie
Original poster
Jul 10, 2009
7
0
Hello,

I am new to the Mac world but have been a fan of my PowerPC G5 for a year or so now. But lately the front upper fan has been constantly at full speed creating a loud whirling sound.

I have done a full diagnostic with the start up disk, made sure there is plenty of open space around the tower, I have blown it out with an air can, and even repaired disk permissions and have ran some virus tools... nothing seems to work.

This problem came out of no where and I need help as the noise is bothering everyone around me. Can anyone give me some advice?
 
Usually that's the symptom of a bad temperature sensor, but I'd kind of expect the hardware test to have noted that.

If you don't already have one available, download a program that can display the readings from the internal temp sensors. See if any of them (presumably the one in that area) are reading very high; that would tell you that either something happened to it or it's disconnected (temp sensors usually pin high if the connection is open).

If you're not sure post the numbers here and me or someone else with a G5 tower can compare.
 
Ok so I got some numbers off of iStat Pro and the temps and RPMs are as follows:

Temps: HD-38, CPU A-76, CPU A ambient-31, CPU B-63, CPU B ambient-31, backside-40, Drive Bay-29, GPU-86

RPMs: CPU B Pump-2900, CPU A Pump-2900, CPU A Intake-2661, CPU A Exhaust-2927, CPU B INtake-2922, CPU B Exhaust-2870, Drive Bay-1000, and slot-237.

Do these numbers seem high? And which one should I be concerned with?
 
The temps look reasonable (CPU-A is possibly on the high side, not really familiar with G5s though). Have you checked Activity Monitor to see if something is pegging your CPU(s)?
 
My G5 isn't liquid cooled, but a little Googling shows those numbers to be on the high side of normal.

At a warm but normal ambient temp (I see the intakes show 30C, but how hot is the room really?) and no load, I would expect to see CPU and GPU temperatures somewhere in the 50C range (though 60C might not be out of the ordinary), with corresponding fan speeds of maybe the 1000-1200RPM range. Going to depend on the particular GPU, of course

Your CPUs and GPU are well within spec assuming they are under load, but if they're running that hot with the fans at nearly 3K (not sure about yours, but usually max for the CPU fans is 3200-3600RPM) and they are NOT under load then I'd wager either something is wrong with the cooling system or there's an airflow problem.

What is the CPU load in Activity Monitor? If it's up near pegged, could just be that you've got a runaway process chewing up CPU and causing a corresponding spike in fan speeds. If it's very low and they're still running that fast, and your room isn't ridiculously hot or something, then there's something amiss.

Incidentally, based on the absolutely ridiculous amount of air my G5 is capable of moving with the fans maxed out (which it only gets even close to when it crashes and they peg as a safety measure), if yours really are at 90% of max speed that must be incredibly noisy.
 
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