My 1.5 year old 27" iMac has developed a buzzing noise. The noise doesn't happen all the time but once it begins, it seems to stay, The system is on a level surface so it is't a vibration noise. The sound seems to be coming from the back. Any thoughts? Thank you!
iMac (27-inch Mid 2011), OS X Mountain Lion (10.8.4)
Please do both a SMC and PRAM reset at lest 3x each. Instructions can be found at:
https://discussions.apple.com/docs/DOC-3603
Please post back with results.
Please do both a SMC and PRAM reset at lest 3x each. Instructions can be found at:
https://discussions.apple.com/docs/DOC-3603
Please post back with results.
Hello,
Thank you. So far your tip seems to be working. I neglegeted to mention in my original query that the sound dimished in volume if I took the brightness down.
I went thru and reset the SMC and PRAM but I only did the process once for each. So far so good.
Thank you!
Great! Glad that solved the problem. Also thank you for the acknowledgment.
I have the same problem on my late 2012 27" i Mac. Took it to Apple genius bar, they ran all of the soft ware fixes, and the problem is still there, but worse.
Sfter Genius bar failure, I tried the PRAM rest three times and decreased the noise to a low level. But not all gone
So I just installed the Vesa Mount and had some issues with the back latch so after i finally got that to work and mounted it i noticed a buzzing from my iMac in the top left corner. I googled it and thought i would have to replace my power supply but something amazing happened... I came into my house and and in my office it was dead silent and i noticed that same buzzing coming from my dimmer switch which powers the outlet my iMac was plugged into. I immediately moved the iMac plug to a different one and had an electrician friend come over and tell me the dimmer switch had issues when the brightness was low due to insufficient power return. That is why the buzzing got low when the brightness was high. So maybe it could be the switch or a plug. I know this an old post but maybe it can help someone as so many post have helped me.
this solved it for me!
27" iMac has developed a buzzing noise
