High pitched whining sound from LED
I got one of the new aluminum macbooks on black friday and have no problems with it until today. I was doing a video chat with my friend and all of a sudden I heard a high pitch whining noise. I thought it was coming from his computer but I muted the sound and still heard it. It sounded like it was coming from the left side near the power plug so I unplugged it (btw I was at 100% charged.) It seemed to rev down like it was a fan or something but then it started again. I plugged it back in and still nothing. I gave up and let it whine for a few minutes and finally I ended up lowering the brightness and sure enough, it pretty much stopped. I put it down to 1 notch and it was gone. I quickly put it back to halfway and heard it again. So I guess when I unplugged it, the brightness fell from 100 to half and thats why I heard the the whine rev down. I let it sit at 1 bar of brightness for awhile and now the noise hasn't come back. Any ideas if this is a big problem? Should I return my macbook?
I'm having the same EXACT problem as you. My 13" Macbook (aluminum case) was on for about 2 hours or so and the high pitched sound started. The most ANNOYING ... and it goes down as you lower the brightness. The only thing that fixed it was rebooting -
Now, this is why I think many people don't hear it (including us)
1. You have to be in a relatively quiet room to hear it
2. You have to have very good hearing in the upper frequency area
3. You have to have your display pretty bright
I called Apple and they suggested I send it in or go to the Apple store.
I'm thinking of going to the Apple store because I really don't want to get the "We checked it out and everything is okay" line -- I know they have been having these problems with other displays too (according to Apple tech support)
Also, to comment on what someone said about thinking it's the fan -- TRUST ME ... this is not a fan issue - This is coming from the backlight. It's way too high pitched to be a fan issue - THis is about 10,000khz and is bordering inaudible (maybe 15-17,000khz) - The sounds changed instantaneously as you make a brightness adjustment