Clicking/static noise from iMac G5, other models

iMac G5

We continue to receive reports of a distinct clicking noise emanating from iMac G5 power supplies. In most cases, users are able to obtain a replacement power supply that does not exhibit the noise problem, which Apple claims only affects 'AC-Bel' branded power supplies plugged into 220 volt outlets (if you are having the problem with a another brand of power supply or in a 120 volt outlet, please let us know)

In some cases, Apple is apparently asking users to send entire iMac units for inspection. One MacFixIt writes:

"I just bought 20" iMac and noticed an annoying constant hum emanating from the power supply. Apple seems to be aware of the issue, because they wanted me to send back my whole machine to investigate. I opted for them to send me a new power supply to swap out myself instead."

Brightness setting affects loudness A number of readers also confirm that the brightness setting on their iMac G5 display correlates with the level of noise generated.

Chad Wadsworth writes "I also feel that my iMac 20" is too loud and have had a hard time isolating the irritation. The noise is definitely more of a high frequency hum that changes intermittently.

"I just woke the system from sleep so with the power save set to automatic, the system is now at its quietest mode yet I can still hear a faint buzz. I opened the display control panel. Here's what I found: Maximum brightness- distinct buzz, Minimum brightness - silent."

Fan problems MacFixIt reader Doug Smith reports that, in his case, a slightly bent internal fan was causing a clicking noise. Some home handiwork resolved the issue:

"For the first year I had my PowerMac Dual G4, I would intermittently hear a rat-a-tat-a-tat sound (loud clicking) from the machine. This happened especially at shutdown (one could hear the rate slow as the fans slowed). A few times there was a 'clunking' sound on shutdown.

"While I had the machine open to install more memory I carefully rotated each of the fans including the two in the power supply. One of the power supply fans was slightly binding between the blades and the fan casing.

"Carefully, I held a small piece of emory paper (very fine 'sandpaper') between the fan blade and the spot where binding was occurring and moved the paper back and forth across the spot several times. That was about 1 1/2 years ago and there has been no noise since then.

"I did not use my fingers to rotate the fans, but a small instrument. The amount of binding was small but noticeable."

Hard drive likely causing PowerBook G4 clicking noise Yesterday we noted other unexpected clicking and chirping noises coming from PowerBook G4 models. Other reports indicate that this noise may simply be indicative of normal hard drive operation.

Keith Olson writes "Ditto clicking on 15" Al PB, seems like pretty much same symptoms on mine except: I went over mine with a stethoscope while it was clicking and seems to come from the area of front left corner of trackpad, which I think is the area of the hard drive. Have hung out at an Apple Store Genius Bar for an hour or so trying to demonstrate it but of course then it never happens. My gut feeling is it's maybe related to heat but certainly to activity."

MacFixIt reader Jeff adds "My 15" Aluminum PowerBook also makes a weird crispy, static, Geiger counter-like sound -- much as George Brownstone described. It happens whenever the energy setting is set to Highest Performance. I just figured that was the trade off that particular power setting..."

Power Mac G5 power supply 'buzz' persistsWe previously noted issues with excessive Power Mac G5 (first generation) power supply noise. In some cases, Apple replaced users' power supplies -- which helped for a portion of readers but did nothing to resolve the issue for others.

It seems the problem persists into second-generation models.

One reader writes "I've had two dual 2.5GHz Macs, each with the characteristic of having a 'buzz' (I suppose high-pitched hum would be a good description too) seemingly coming at least partially from the power supply. The buzz is present from the moment the machine is switched on until the moment it is switched off, seemingly just a little bit worse if left running overnight. And it's above and beyond the normal low-level fans that come and go depending on cpu activity.

The second machine replaced the first, as the first machine was so bad it gave me headaches, due to the volume and the pitch of the buzz. The second machine is better, but only to the non-headache level (not as loud); still is a little bit nerve-wracking (and seems to get the ears ringing a little bit). I thought seriously about returning it too (today is the last day I could do so), but since it is so near-perfect otherwise, and my old B&W G3/450 made quite a racket last night when I turned it on, I've decided to keep it and at some point have it worked on."

If you're having a similar noise problem, please drop us a line at late-breakers@macfixit.com.

It should be noted that a number of the above mentioned sounds may be resultant of normal operation and considered to "within spec" by Apple. Also, we've yet to receive a report of actual hardware failures occurring from any of the above noise issues.

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