[bondsteel]

My 2.0 Ghz MBP makes a very low humming sound, kind of like my G4 did when the processor was set to full performance. However, my MacBook Pro does it at all energy settings. Has anyone else noticed this? Wondering if it is unique to mine.

Otherwise, it is amazing.

[danonamac]

Yep, mine too. Seemed to go away after it warmed up.

[ll350]

I read that that has something to do with the display being set below it's highest brightness setting, the backlight elements make a noise when they aren't running at full power.

[thephotodork]

As a side note, my 17-inch Apple Studio Display also would make a distinct humming sound until it warmed up. Not saying that this is using the same technology as those 3-5yr old desktop LCDs, however it could be a similar phenomenon.

[spiky_dog]

Originally Posted by ll350

I read that that has something to do with the display being set below it's highest brightness setting, the backlight elements make a noise when they aren't running at full power.

my MBP is going to be replaced under AppleCare as DOA because of the display whining issue. not all of the machines exhibit this whining noise, and i consider it unacceptable (i'm a musician in my other life, and have sensitive/neurotic hearing).

description of my MBP's whine for the archives:

- not present at 0 brightness or full brightness
-- present at every brightness level in between

- not affected by processor load
-- running a proc-heavy app such as Photo Booth does nothing
-- switching cores on and off through the Better Performance/Energy Savings settings does nothing

- not affected by the "Automatically adjust screen brightness" setting when at full brightness
-- the whine is present when it's manually or automatically adjusted down as you'd expect

in summary there are at least two causes of whining on the MBP. one is from the processor and is affected by processor load; another is from the display and is affected by screen brightness settings. also, if this issue annoys you sufficiently and you report it in time you can get your machine replaced by Apple as DOA.

i just hope that the replacement does not exhibit this whining noise... if that happens i'll DOA it again, get a refund instead of a replacement, and personally audition machines at the local Apple Store until i find a quiet one.

[darcybaston]

Is this noise similar to the hard drive whirring fruity iMacs made?

[Troll]

Made made a noise on low brightness settings when I first unpacked it. It was exactly the whine my TiBook has. It's mysteriously disappeared though. Dunno what I might have down but it's gone now.

[spiky_dog]

Originally Posted by darcybaston

Is this noise similar to the hard drive whirring fruity iMacs made?

this noise is definitely not from the hard drive. it disappears without fail 100% of the time when the backlight is off, and diminishes greatly or disappears the vast majority of the time when the backlight is at full brightness. i've heard loud and dying hard drives, and this is not the same noise.

[spiky_dog]

Originally Posted by Troll

Made made a noise on low brightness settings when I first unpacked it. It was exactly the whine my TiBook has. It's mysteriously disappeared though. Dunno what I might have down but it's gone now.

does it appear on all brightness levels, or just low brightness levels? on my soon-to-be-returned unit the noise starts immediately at the first "click" below full brightness, reaches peak intensity at about halfway down the scale, and maintains that intensity with a different timbre all the way down to one click above the backlight being turned off. also of note is that it didn't make this noise initially, but only started after about a week of (heavy but not absurd) use.

[spiky_dog]

an update: my replacement machine (picked up in person at the apple store university village here in seattle) does not have the same buzzing noise from the display that the first one exhibited.

[cgijon]

read other peoples comments before posting, shesh.