Previous 1 2 Next 15 Replies Latest reply: Feb 21, 2011 6:14 PM by Lelouch vi Britannia
Lelouch vi Britannia Level 1 Level 1
so basically, as the title says, my computer is making a really loud noise as soon as I turn it on, I am presuming it is the fan.
Over a month ago, my computer started to constantly crash, and about two weeks ago I took it to a Genius Bar for a diagnosis. The problem was a hard drive failure, so I had it replaced and yesterday I brought it back home.
However, after the fix, the computer now runs fine, but there is a really loud noise from the computer.

I have tried resetting the PRAM and SMC like some other threads have suggested, and none of them have worked. I have tried restarting, shutting down the computer and everything suggested.

The computer has never made this noise in this manner before.
Before the fix, the only time it would be noisy like this is when I wake it from sleep, just left it there (on screen requiring username and password) and it sleeps again, and if I wake it from sleep, then it would be loud like this, but that is solved by just simply sleeping the computer again and waking it, and it will be all quiet again.

However, now, it makes this loud noise as soon as I turn the computer on, and as long as the computer is not shut down or asleep, it will make this noise.

Before the fix, my OS was 10.4.11, but the Genius Bar had installed 10.5.8 on this hard drive.

Is this a software problem or a hardware one?
Anyone got any suggestions or ideas how to fix this?

I have called the Apple store I visited for this fix already, they push me over to AppleCare and AppleCare pushes me back to Apple store and they tell me they cannot provide technical support over the phone and would need me to take the computer back to the Genius Bar.

I am just not happy about this. I live almost an hour away from the closest store and I have university to attend to as well.
So I am hoping this problem can be resolved without having to go back to the Genius Bar, although all methods I have read so far do not help.

From Lelouch

iMac 24" (Late 2006), Mac OS X (10.5.8)
  • rkaufmann87 Level 9 Level 9
    Try doing the SMC reset, please carefully read these instructions.


    • Shut down the computer.
    • Unplug the computer's power cord _and all peripherals._
    • Press and hold the power button for 5 seconds.
    • Release the power button.
    • Attach the computers power cable.
    • Press the power button to turn on the computer.


    • Shut down the computer.
    • Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
    • Turn on the computer.
    • Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
    • Hold the keys down until the computer restarts and you hear the startup sound for the second time.

  • Lelouch vi Britannia Level 1 Level 1
    I have definitely done both of those correctly multiple times.

    SCM Reset, I only have the power cord and keyboard to unplug, which I unplugged.
    Held the power button for 5 seconds. And then plugged everything back in to turn it on.

    PRAM Reset, definitely got the keys and heard the start up chime twice.

    Both did not work and the loud (fan?) noise is still persisting.

    Thanks for trying.
  • rkaufmann87 Level 9 Level 9
    Try restarting in Apple Website
    Safe Mode, that clears out some of the caches. It's possible yours has become corrupted, if not post back and we can try a couple of other things too.
  • Lelouch vi Britannia Level 1 Level 1
    Not sure if I did it right or missed anything out.
    But I followed the instructions:
    Turn the computer on.
    Heard start up chime and held down shift.
    Took me to log in screen and it said Safe Mode in red.
    Logged in.

    And that was all I did.

    If that is all that needs to be done and is suppose to solve the problem, then it has not worked, problem still persists.
    And please do suggest everything that could solve this, I am prepared to try it all.
    Taking the computer back and forth is not a good option for me, as I live an hour away and have university to attend to.

  • rkaufmann87 Level 9 Level 9
    If it said it started in Safe Mode then it did. The next thing I'd recommend is doing an Apple Hardware Test. Please run it in extended mode, if it reports any errors please post the codes.
  • Lelouch vi Britannia Level 1 Level 1
    Right, I ran the extended Apple Hard Test and an error was brought up.
    The error code/message was:

    4SNS/1/40000000: THOP

    I never thought Apple Hardware Test actually works, seeing as it said everything was fine when I had a hard drive failure before.
    So, please provide further guidance.

    Many Thanks,
    From Lelouch
  • Lelouch vi Britannia Level 1 Level 1
    So I ended up having to take it back to the Apple Genius Bar, they did not tell me what was wrong exactly, but it is now fixed, I just hope no other problems occur.
  • Lelouch vi Britannia Level 1 Level 1
    Just had it fixed at the Genius Bar.
  • Edward Boghosian Level 4 Level 4
    Attached to the computer when you get it after the repair is a work order that specifies what has been changed.
  • Lelouch vi Britannia Level 1 Level 1
    Nope, nothing from it.
    And seriously, their job on my computer is quite shoddy; a fix on the hard drive made the computer go really loud, and now that the loud (presumably, fan) noise is no more, when it is quiet enough (which is most of the time when I do not have music on), I can hear a "wind-like" noise from the computer, which has never been heard before prior to the computer being fixed, and I mean never.
    It is totally distinguishable from the regular computer noises, I thought it was quiet enough that it would not bother me, but it is bothering me, and makes me wonder is my computer going to break down once again soon.
    Should I be concerned about this "wind-like" noise? I would really hate to take it back yet again.
    I have been back and forth three times already; travel, time and cost are problems, Apple just needs to realise this and sort things out nice and clean.
  • Lelouch vi Britannia Level 1 Level 1
    New problem, please read my new post and see if you can help.

  • Edward Boghosian Level 4 Level 4
    Here in my little part of the U.S., not far from N.Y.C., I have always been given an initial work order that specifies the problem. When the computer is returned, there are two work orders; one you sign and Apple keeps and one that you keep. On the work order is described what has been changed. Once, when an authorized Apple repairman came to my home, the same procedure was followed. I would think the same thing is done all over.
    The wind-like noise you referred to may be the air being sucked in by a fan. If it is very loud then it may be the fan spinning at a very fast rate which should be checked into. Do you have any temperature and fan speed monitor software that would check the temperatures and fan speeds? I have Hardware Monitor but there are others. If a fan(s) is too fast, it is not normal and should be checked into.
  • Lelouch vi Britannia Level 1 Level 1
    Hi, well, the thing is, I am just worried that, while making other repairs, they might have damaged something unintentionally and probably do not know about it, which would not be documented.

    My initial problem of a loud fan, after a hard drive replacement, was fixed, so I do not hear it anymore, but this wind-like noise is different. With the iMacs, I presume the fans are towards the top, which was where the loud fan noise came from, however, this wind-like noise seems to come from the bottom of the computer screen are, centre and right side (in the direction I face it), but not the left side.

    I describe it as wind-like, but it sounds a bit like when the computer is on heavy demand and the computer loads, yet different as it is quieter and slightly different in pattern, and unlike the usual heavy demand noise which comes from the top, it comes from the bottom.

    I actually installed a temperature widget after my last repair, just in case my fan was just simply tuned off and would not come on at all for the sake of fixing the loud noise it was making.

    The temperatures read as follows:
    HD: 31
    CPU: 27
    Ambient: 17
    GPU: 36
    GPU Diode: 46
    GPU Heatsink: 36
    HD Bay: 33
    Optical Drive: 30

    To my knowledge, these should be fine temperatures?
    But the noise persists regardless. The noise can instantly be heard (providing that it is quiet enough) as soon as the computer starts up.

    From Lelouch
  • Edward Boghosian Level 4 Level 4

    Can you determine the different fan speeds. If a fan is constantly going too fast, it could be that a sensor wire is not working or is disconnected. If this is the case, computer would speed up the fan(s) because it would assume the maximum temperature as the default and make the fan max out. Is a lot of air being blown out through the circular vent at the back? In my computer, that is where the HD fan is located. I think if the technician did something wrong, it would be documented. Whether your being told about it is another story. But if something is incorrectly repaired, Apple, I think, would correct it or in my case give a new computer.
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