Solution to excessive fan noise on Power Mac G5?

Nein01

macrumors 6502
Original poster
Dec 1, 2009
307
1
Germany
ok, so i'm not sure if this is just a coincidence or not just yet, but after uninstalling LCC (logitech control center), my fans have been acting NORMAL! for HOURS so far! :eek:

constant, loud fan noise is an issue i have been having for a very long time, and apparently so have many other G5 owners. during my search for a solution, i came across several webpages full of posts from users in distress over the same problem i was having.

apple tried replacing the logic board - nothing.
tried pram reset - nothing.
tried creating a new user account - nothing.

couldn't use smcFanControl because of the PPC chips.

long story short, i gave up on it and just suffered through the annoyance of having fans that were louder than any music, movie or game being played at a normal volume. i can't believe that in all my searching for an answer that i never came across anything that suggested i uninstall my logitech mouse drivers.


so i guess that's why i'm posting this.. for others who may be having the same problem and nothing else has worked, hopefully google can help them find this thread. if you are using logitech drivers for your mouse or keyboard, uninstall them! i switched to SteerMouse about six hours ago and haven't been disturbed by my fans since then. hopefully this is the real deal! i'll post an update if the problem comes back.
 

300D

macrumors 65816
May 2, 2009
1,284
0
Tulsa
Knowing what G5 you have would be a huge help to us. A G5 should have quiet fans unless the CPU(s) are hot or there is a high electrical demand to the expansion slots (multiple video cards, raid card, etc).

Get iStat pro and check your fan speeds, they should be about the same as this:
 

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Transporteur

macrumors 68030
Nov 30, 2008
2,729
3
UK
So are the fans just running faster than normal, or are the fans generally loud?

If you simply got loud fans (even at lowest speeds) you could swap them for more silent ones, which is what I did with my late 2005 G5.
 

rickvanr

macrumors 68040
Apr 10, 2002
3,256
11
Brockville
Which graphics card do you have? I had the 6800 Ultra in my water cooled G5 and the whole thing always sounded like a diesel engine.

It quieted down a bit after I did a PRAM reset, and SMU reset but eventually it got back to its trusty industrial wind tunnel noise levels.

Mine could have been slowly leaking coolant though, I don't know if that happened over time, or just suddenly. If it was a slow process, that could explain the fans going faster trying to compensate.
 

Nein01

macrumors 6502
Original poster
Dec 1, 2009
307
1
Germany
sorry i never mentioned the specific model. it's a 2.0ghz that i bought in May of 2005. i think the liquid cooled systems had just come out at that time but i didn't go that route.

Model Name: Power Mac G5
Model Identifier: PowerMac7,3
Processor Name: PowerPC G5 (2.2)
Processor Speed: 2 GHz
Number Of CPUs: 2
L2 Cache (per CPU): 512 KB
Memory: 3 GB (originally had 1gb)
Bus Speed: 1 GHz

graphics: ATI Radeon 9600 XT


i came back to this thread to say that the problem in fact HAS improved significantly ever since i uninstalled LCC, although i still have the occasional sudden burst of loud fan noise for no apparent reason, which can last for several minutes at a time or longer and sounds similar to a kernel panic. i haven't done any cpu intensive work on this computer for a long time now, since my school has new imacs, so it really bothers me that i have to suffer through this noise sometimes when all i'm doing is listening to music, watching a movie, or browsing the web.

to 300D, i do in fact have the iStat pro widget, so i will try to remember to post my fan speeds the next time i catch them being obnoxiously loud.

for now though, here is the fan reading while it's quiet (only safari is open):



only the CPU B intake and CPU B exhaust readings are fluctuating. they are going up to around 1400-1700rmp with a soft hum. at the 300-400 range (the lowest i saw) it's very quiet. all the other fan readings are staying exactly the same as they are in the pic.




edit: just woke my computer up from sleep mode and the noise started instantly



still nothing but safari running. looks like CPU B speeds went up a couple hundred more rpm than the max they were at before, but the noise coming from my computer is exponentially louder, like a kernel panic.

only other difference is that the drive bay fan went up to 1048 from 1000 and some temperature changes have occurred -- however, the CPU A temperature went from 1 degree celsius to 41 degrees while every other temperature went down (which seems normal since my computer was in sleep mode for a while)
 

Soleon

macrumors newbie
Jan 15, 2018
5
3
Not sure if anyone will be able to help me with this kinda thing 8 years after this thread was last active, but I've got a PowerMac G5 with the dual 2.3 processor, and I'm having an issue with fan noise. I have a trial of iStat on, and it confirms my visual inspection of the weird blower-looking fan by the hard drive, presumably the "Backside" fan running at 3000 RPMS. It's extremely noisy, and I'd love to find a way to make it chill out without simply unplugging it or removing it. Somewhat interestingly, I've found my four main processor fans won't spin above about 500RPMs, which seems weird, since the processor is at around 65C (I'm American but my temp program was set to Celsius so I'm familiar with it in that regard now) but maybe there's some kind of hardware or software issue causing the backside fan to run super high and the processor fans to barely run? The yellow light that indicates the clear cover is open isn't lit, but does light if I remove the cover. Any ideas would be greatly appreciated.

As to why I'm using a dinosaur like this 13 years later - my main PC is a rig I built a year or so ago, but my motherboard failed, and I need a PC to use while it's shipped off (fortunately under warranty). So I booted up the old PowerMac, and it works fine, but this fan noise is new - I'm used to it going full leafblower when I'm making it work, but that's a deep, throaty noise from those processor fans, and this is just an annoying, tinny whistling that starts about a minute after I turn the thing on and doesn't stop for anything, no matter how little or much the computer is doing.
Thanks in advance!
 

RhianB

macrumors 6502a
Sep 3, 2016
857
960
505 USA
Hi. If you have an Apple service diagnostic disc, boot from it to check your PMG5 temperature sensors, recalibrate your fans for better operation - all sorts of neat stuff. Also, it sounds like the box sat around for quite a while - It would be worth popping it open and cleaning it out. Here's a video of a guy using ASD to work on a unruly PMG5.


Good luck :)
 
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AphoticD

macrumors 68000
Feb 17, 2017
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Not sure if anyone will be able to help me with this kinda thing 8 years after this thread was last active, but I've got a PowerMac G5 with the dual 2.3 processor, and I'm having an issue with fan noise. I have a trial of iStat on, and it confirms my visual inspection of the weird blower-looking fan by the hard drive, presumably the "Backside" fan running at 3000 RPMS. It's extremely noisy, and I'd love to find a way to make it chill out without simply unplugging it or removing it. Somewhat interestingly, I've found my four main processor fans won't spin above about 500RPMs, which seems weird, since the processor is at around 65C (I'm American but my temp program was set to Celsius so I'm familiar with it in that regard now) but maybe there's some kind of hardware or software issue causing the backside fan to run super high and the processor fans to barely run? The yellow light that indicates the clear cover is open isn't lit, but does light if I remove the cover. Any ideas would be greatly appreciated.

As to why I'm using a dinosaur like this 13 years later - my main PC is a rig I built a year or so ago, but my motherboard failed, and I need a PC to use while it's shipped off (fortunately under warranty). So I booted up the old PowerMac, and it works fine, but this fan noise is new - I'm used to it going full leafblower when I'm making it work, but that's a deep, throaty noise from those processor fans, and this is just an annoying, tinny whistling that starts about a minute after I turn the thing on and doesn't stop for anything, no matter how little or much the computer is doing.
Thanks in advance!
I’ve found the drive bay fan is quite noisy in my DP G5s (prior to the late ‘05 model). This seems to be the first fan to rev up to full speed and makes it sound like it’s getting ready for take off.

You could try cleaning out any dust from the fans (and PSU) and applying new thermal paste to the CPUs to reduce heat. Also, check that the air deflector sensor is working by removing the perspex door while it’s running. If the fans speed up when removed then it’s as it should be, if they stay the same then it could be just a failed sensor (in one of the bottom grooves for the door) causing constant fan overdrive.

Also, it’s a big job, but you can move the drive bay sensor down from that top hot air pocket above the HDDs and stick it underneath the drives instead. It requires a complete teardown of the tower but should reduce the drive bay fan from firing up as much.

Another thing to check is the HDD(s). Old (original stock) HDDs are going to run hotter than more recent (2010+) drives. If you’re replacing the HDD, make sure it’s a model which is SATA II (3G) spec or a SATA III spec which can be jumpered down to 3G. SSDs are another option and in my experience in the G5, a modern SSD is cooler running than a 15 year old 7200rpm thrasher.

Lastly, I had a 9800 Pro Mac Edition GPU for many years and I thought my G5 was just noisy as it always made a high pitch fan noise, which would come on at seemingly random times. I replaced the GPU and the high pitch fan noise was gone. In short; the noise may be the GPU’s little cooling fan and not the G5.
 
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Soleon

macrumors newbie
Jan 15, 2018
5
3
Hi. If you have an Apple service diagnostic disc, boot from it to check your PMG5 temperature sensors, recalibrate your fans for better operation - all sorts of neat stuff. Also, it sounds like the box sat around for quite a while - It would be worth popping it open and cleaning it out. Here's a video of a guy using ASD to work on a unruly PMG5.


Good luck :)
Hey, thank you for the rapid response, I really appreciate it!
Great video, thanks for showing me- do you think I'd still be able to get hold of one of these ASD discs? I searched it up and some thread suggested calling Apple and demanding one... Think that may yield some results?
 
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AphoticD

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Feb 17, 2017
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Hey, thank you for the rapid response, I really appreciate it!
Great video, thanks for showing me- do you think I'd still be able to get hold of one of these ASD discs? I searched it up and some thread suggested calling Apple and demanding one... Think that may yield some results?
A quick search reveals this zip of the dual boot DMG: (216.3MB)
http://www.dreamsupport.us/downloads/apple-mac/Apple_Service_Diagnostic_Disks_25_GB/ASD v 2.5.8 Dual Boot CD (2005)/ASD 2.5.8.dmg.zip

Download and burn with Disk Utility, then pop it in and check the Read Me file for instructions on booting.
 
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Soleon

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Jan 15, 2018
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AphoticD

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Feb 17, 2017
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Thank you... Sorry for my overwhelmingly evident inability to use a search engine, but I greatly appreciate the help!
No problem. I have a feeling if you called Apple and asked for it (or demanded it), they might say something like "What's a G5?"
 

Soleon

macrumors newbie
Jan 15, 2018
5
3
What's a G5?

:D

If you REALLY want to blow their minds, show them the built in clear plastic lunch tray Steve & Woz were thoughtful enough to engineer into it.
HAha, very true. (I apologize for any typos, I'm on the G now ad its porcessor fans are clearly not doing their job)
I downloaded and burned the image to a CD, and stuck it in the drive and used first C, and then Cmd Opt Shfft Del, but the screen I got was grey with a small icon blinking between a Finder logo and a question mark. Any suggestions?