Hello, This noise is hard to pin down. It goes away when put to sleep, but reappears when woken: same with shut down and restart.
All apps are off and peripherals unplugged except ethernet.
Sometimes it goes away, but seems to come back when playing audio files or YouTube videos.
There's not much about this from a forum search.
Thanks for any help or ideas.
Chas
Intel iMac late 2013
OS 10.10.3
2.9GHz Intel Core i5
A few times in the distant past, I have heard where the optic sensors on some Mice caused audio white noise. I'm not sure if the problem(s) were caused by USB or a wireless mouse, but I'm guessing that it could be either one depending on your audio setup and/or how you are recording.
Chas,
When you hear it, open Activity Monitor (Applications - Utilities - Activity Monitor) and see what apps are running. Methodically go through them and quit apps and then listen, if it is app related that way you can narrow it down to a specific app.
Fan noise huh? Whoda thunk it?
You might try running Apple Diagnostics to see if it reports an error. OS X Yosemite: Use Apple Diagnostics or Apple Hardware Test
Regarding Activity Monitor apps that are listed as being used by you can be turned off, if they're being used by the system you probably shouldn't mess with them. Does the fan noise exist if you're booted in Safe mode? Try safe mode if your Mac doesn't finish starting up - Apple Support
White noise continued all during boot in safe mode and restart.
I shut down and unplugged for several minutes, but noise was still there during start up.
Thanks for the suggestion though; made sense to try.
Hello, I appreciate the help so far. I've dug a little deeper...
It is a constant high speed fan noise; sounds like white noise.
Resetting the SMC and pram ddn't work. I took the machine to the Genius bar, but the fans then would not go into high speed; All behaved perfectly.
They ran a bunch of diagnostic tests. All elements showed as fine.
I got the iMac home and it worked well for a while, then the fans went to high again. Resetting SMC, again has no effect.
Thinking it may be a hardware problem with the fans?
Thanks
Yes the fan noise cranks all through start up in Safe Mode.
I shut down and unplugged for maybe 30 minutes and on restart, all was quiet.
I started playing a music video from YouTube and they came back. Same once when I used iMovie; all quiet then came back when I was editing a movie.
thanks for the reply
Boot into Safe Mode, Mac OS X: Starting up in Safe Mode, and see if the noise continues. Does it?
Does it sound like it could be a fan noise? You might try resetting the SMC Resetting the System Management Controller (SMC) on your Mac - Apple Support
Chas Williams wrote:
it seemed that all apps were off.
That is impossible! Please carefully read Apple's Use Activity Monitor on your Mac - Apple Support
As an update, I just repaired permissions and restarted. White noise all during restart.
Repairing permissions is a total waste of time. However one thought is to go to Adobe's website and ensure the version of Flash you have is up-to-date. Many Youtube videos rely on Flash.
Thanks for the reply.
It's definitely not fan noise; white noise generated by something.
I'm not familiar with the Activity monitor, but it seemed that all apps were off.
Noise is still constant.
Thanks
I did open AM and check for apps running.
Hello rkaufman87, are there any apps that will hurt anything if I turn them off? There are a lot of them that I have no clue what they do?
Thanks for the help,
Loud Constant White Noise
