Is there a strange sound coming from your iMac?

Hi Linda

Quick question for you, is that speakers system connected to the output jack or is it a USB setup?

I ask because inserting a mini stereo plug into the output jack of the Mac, switches the MIDI setup from internal to external output jack disabling the internal speakers.

Also opening Garage Band will reset your MIDI setup, sometimes this will clear up audio issues.

Dennis

17" iMac Intel Core Duo - 2GB Ram - Mac OS X (10.4.10) - Maxtor 300GB FireWire - Creative Inspire 2.1 - 2G Nano

Hi, there are sounds within the computer when certain actions happen..ie..Mail Sent(sounds like a whooosh) Try System Preferences->Sounds and choose/reset sounds. Sounds can be personalized..L

If you are using an audio app. like LineIn, check to make sure that the Pass Thru is off. With LineIn gray is on and white is off, for the Pass Thru button.

LineIn

17" iMac Intel Core Duo - 2GB Ram - Mac OS X (10.4.10) - Maxtor 300GB FireWire - Creative Inspire 2.1 - 2G Nano

My 20 inch iMac (new Aluminum model) has created a buzzing noise 2 times. The first time I restarted the computer. This fixed the problem for that day.

About 20 minutes ago the buzzing started again. This time I tried muting the sound, which had no effect. the display backlight is dimmed (by adjusting the brightness on the F1 and F2 keys). However, adjusting the backlight up or down makes the buzzing less intense until it goes away. The frequency of the buzzing is constant at about 60 Hz.

Searching the Support site, your thread is the only thing I see related to buzzing on an iMac. I am going to call and if this is a known issue.

John

This is almost certainly an issue with the screen inverter that was infamously present on some of the early MacBook Pro models.

The bad news is your system is faulty, however, it is also problem that can be fixed easily simply by getting apple to replace the screen inverter. I was not aware that this problem was present on any iMacs, but I suppose they must use the same piece of hardware to do the job.

Also, does the buzz go away or quieten when the display is at full brightness? That would further suggest that you have the screen inverter issue.

Anyway, good luck on getting it fixed!

This is almost certainly an issue with the screen inverter that was infamously present on some of the early MacBook Pro models.

The bad news is your system is faulty, however, it is also problem that can be fixed easily simply by getting apple to replace the screen inverter. I was not aware that this problem was present on any iMacs, but I suppose they must use the same piece of hardware to do the job.

Also, does the buzz go away or quieten when the display is at full brightness? That would further suggest that you have the screen inverter issue.

Anyway, good luck on getting it fixed!

Joe -

Thank you. Your response is more helpful, and almost as fast as calling Support.

The suggestion from the support line is to figure out what set of conditions cause the buzzing and then take it to a Genius. They did not give any conclusive resolution.

The answer to your question is yes. When the buzzing started, my screen was at the mid setting for brightness. When I adjusted the brightness higher the sound became less intense, and by maximum brightness the sound was gone. I then decreased the brightness and the sound came back. By mid range (in brightness) the sound was loudest, and by minimum range (in brightness) the sound was gone. Several minutes later, I tried playing with the brightness again, but no strange sounds happened.

Thanks again for your information about the MacBook Pro having a similar issue.

Message was edited by: 55mm Micro

this is exactly the same problem I have with my new Alu iMac 20".
everything was fine yesterday when I turned the brightness down to mid setting. when I started up my iMac today the weird buzzing noise came up. I didn't no what to do and waited a bit until suddenly the energy saver lowered the brightness automatically and that buzzing sound had gone suddenly.
now brightness is on its highest level again.
so I guess I have to have it repaired, right?

When I figure out how to reliably get my computer to buzz, I am planning to drive in the the Mac store and have it fixed.

Based on its behavior today, I think that the buzzing happens before the machine warms up (within the first 5 minutes), and while the brightness is in mid-range.

On a positive note -- other than this buzzing, the machine is very quite.

Please let me know if you find out any details about having yours fixed.

Hi Lindy,
I have the same issue with the sound coming from my internal speakers. I have external speakers plugged into the headphone jack. i get this noise when i restart or start up my computer for a few seconds then it goes away. This sound returns when i unplug my speakers after startup and does not go away. i was wondering if u were able to fix this and how.

Thanks
Ryan