Noisy G5iMac

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Posted:
in Current Mac Hardware edited January 2014
My new 20" is great - except for a slight annoying constant whirr/whine/hum sort of low level noise. Noticeable when the background is quiet, but right now I can hear it.

Spoke to Apple - and after a session of diagnosis(?) got sent a new power supply. No joy - just the same noise.

Spoke to them today again. Again quite helpful and willing to spend time - almost immediately bumped up to 2nd level. Got asked to do a recording in iMovie of the sound and email to them for Engineering to listen to. I reckoned it was a noisy hard disc bearing but I have nothing to reference it against. The same Apple person phoned back a couple of hours later with a preliminary report - "they think it is a software problem" How real is that for an answer??? I said I did not agree but would wait for the final report.



Incidentally as I type this the noise level is rising slightly so could this after all be one of the fans? Does any fan run constantly? I will see what happens when I finish this and go quiet - will it quieten down?



Any assistance from others' experience would be welcome.

Comments

  • Reply 1 of 12
    piotpiot Posts: 1,346member
    spylaw4, I am in the same boat! 20 inch iMac G5 and also in London btw.



    I haven't contacted Apple yet. I have been monitoring the Apple Boards



    There seem to be a few issues with noise from either the fans or the power supply. There was a massive thread there that was deleted so I am pretty sure that Apple are well aware of the problem. I am waiting (not in vain I hope) of a better way to diagnose the problem and a possible solution.
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  • Reply 2 of 12
    It's the fan that cools the cpu.



    I have a 17" and have had the mid plane changed for the same problem, sadly it didn't help.



    I have ran the machine with the back cover off and disconnected the power to this fan (briefly!) and the noise stops completely.



    I've decided to live with it for now as I think there are two manufacturers of this particular fan, mine is made by Delta. Some people have reported that they have no problem, others had the problem and a change of unit/midplane solved it. My *theory* is that it's hit or miss as to which fan you get and it is best to wait for a while until Apple gets all of the duff ones out of the supply chain.
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  • Reply 3 of 12
    Quote:

    it is best to wait for a while until Apple gets all of the duff ones out of the supply chain. [/B]



    If this is the case do you think apple should at least check the parts it uses when they come from different companies? If this is the case the fact that these parts made it to market is wrong. Just my 2pence.
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  • Reply 4 of 12
    piotpiot Posts: 1,346member
    Are the fan units user replaceable ?
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  • Reply 5 of 12
    Hi,



    Replacing the fan isn't too difficult but it's not on the list of user replaceable parts, as far as Apple are concerned the answer is no.



    You have to remove the mid plane assembly complete, take off one of the speakers, unclip the fan unit and remove. Then you have to get the cable out which takes just about as long!



    My experience is with the 17" so there might be a few differences with the 20"



    I stripped my fan right down to the bearings, it does feel rough when it turns so I suppose this might be the underlying cause, nothing I could do about it though.
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  • Reply 6 of 12
    Quote:

    If this is the case do you think apple should at least check the parts it uses when they come from different companies? If this is the case the fact that these parts made it to market is wrong. Just my 2pence.





    I'm only speculating about the two suppliers, it just seems odd that not all machines are affected and that taking the same action to solve the same problem only seems to work some of the time.



    Yes, I think that they should have checked both suppliers, especially the supplier of my noisy fan, Delta. I seem to remember that there was some trouble with Powermacs not long ago involving Delta components..
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  • Reply 7 of 12
    Ive got the 17" iMac G5, the fan does get loud but only when playing a heavy graphics game or when using large files in Photoshop, but when just using safari or word or simple stuff, the fans are whisper quiet.
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  • Reply 8 of 12
    Yeh, mine does too. When you have a lot of processor activity you can hear the air being moved by the fans. This is no problem.



    The only problem is the whine/buzz noise that never goes away, it is really noticeable when the room is quiet.
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  • Reply 9 of 12
    Sounds exactly like my problem noise Jake B. I'm wondering about trying to fire it up with the back off and try a non-conductive probe to see if I can locate the noise source - fan or disc. Just how do you switch it on without the button?
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  • Reply 10 of 12
    Place the machine face down with the speakers pointing toward you. At the bottom left, between the ethernet port and the speaker, you will see three small plugs and two metal pins, these pins will depress on springs if you push them.



    To start the machine just short these two pins with something metal for a second or so.



    If you look at the three plugs there is a 1x3 connector, a 2x3 connector and a 2x4 connector. The 2x3 connector is the one which powers the cpu fan, when I pull this one out then the noise disappears, you might want to try this before spending time poking around.



    Just for clarity, the connector has 6 positions but only 4 wires, 2 black, 1 brown and 1 grey.
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  • Reply 11 of 12
    lucidalucida Posts: 104member
    I had the same high pitched whine...



    I noticed that when I press gently on the grey plastic cover over the CPU fan it goes quiet.



    I've stuck a white sticky pad on the cover and now my iMac in totally silent apart fom the blow of air.



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  • Reply 12 of 12
    messiahmessiah Posts: 1,689member
    I had a 20" iMac that had the same problem. I was convinced that it was something to do with the graphics card, because switching resolution seemed to trigger it.



    My machine suffered from a faint high pitched trill ? like an old fashioned kettle boiling. At first, it would only last for a minute or so and then quietly die away... but then it started to remain in the background constantly.



    It went straight back in to the box and back to the seller for a full cash refund. Thank you! Come again!



    I wasn't wanting to get entangled in replacement parts and fannying about...
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