[djmpower]

My iMac G4/700 is making a strange noise which is coming from the base of the computer when using OS X.

The noise resembles a buzzing/hissing noise which occurs when scrolling in most applications (Safari, IE), or when moving the mouse across the dock (magnification off). It also occurs when the screen saver comes on (Flurry).

The noise is quite loud and is getting very annoying. To clarify, I also have external USB Speakers and the noise is not coming from them. It is coming from the base of the computer, possibly the internal speaker.

The noise almost seems like an electrical interference type noise.

Does anyone have any idea what it could be? I already tried turning down the microphone input volume and it did not help elliminate the problem. I also checked and it is not a hard drive noise (the hard drive is pretty noisy as well, but in a humming way).

Any help would be greatly appreciated.

Thanks

[Aku]

I used to get that too on original FP800. No idea what it was, but it went away after I had the power cord hidden for a week while on vacation.

I thought I was going crazy. Really, how can scrolling with the arrow keys cause the hardware to make that noise. It drove me nuts and I'm glad it's gone. I'm still curious what caused it.

[djmpower]

What do you mean by the power cord hidden? Did you move the cord away from other cords?

Please let me know.

I appreciate the help.

Thanks,
DJ

[Paul Stephen C.]

Sounds like a hardware fault. Phone AppleCare without delay.

You get full AppleCare for the first year, even without paying the extra Applecare Protection Plan warranty (which I would recommend). If you have an intermittent problem, give them a call. If it's brand new computer, ask for an exchange rather than a repair, because once you ask for a repair, you will not get a replacement easily, if at all...

I've had a good experience with Apple customer care, and you are paying for it by spending good money on your iMac. You don't get this level of service with grey box PCs, so get the service you've paid for!

Check your docs for the contact 'phone number, and give Apple a call.


Paul

[Aku]

Heh, sorry. Hidden = power cord unplugged and hidden so idiot roomate wouldn't be able to use the iMac while I was away. It might have just been coincidence though. After 10 months of that noise, it hasn't made it the last 3 weeks, when I got back and plugged it back in.

[drcarl]

I too have been getting this noise while scrolling since the day I plugged in my iMac (17" 800MHz). Always thought that it was some feature that I didn't know how to turn off. It sounds kind of like a penny clinking into a piggy bank (low volume, high pitch, short duration).

I get the clink for every key that I press on the keyboard that produces a character on the screen. A clink for every millimeter that I scroll a window. Multiple clinks when I move or minimize a window. The clinks occur regardless of whether my Apple Pro Speakers are plugged in.

Does any one else know more about this problem? Is it serious? My iMac's been chuggin away perfectly aside from this.

[Johnnyboysmac]

I think Paul is right, in that if you have paid for Applecare, then you should give them a call.

Here's a thought, though, which struck me after reading the comment about hiding and later reinstalling the power lead, and it reminds me a little of my HiFi experiences.

All computers give off RF (radio frequencey) interference to some degree or other. Power leads also can generate mains hum fields that will interfere with other signal leads placed nearby.

Try to keep your AC mains power lead separate from your signal, ie speaker leads, and also from other leads containing power, such as USB leads etc, although here I would think the amps flowing would be miniscule and unlikely to cause interference, unlike the AC mains lead.

As a general rule, within the HiFi arena, power and signal leads should always be separated by a minumum of an inch or two, and where they touch, try to run them at right angles (90 degrees) if possible.

This may sound like hokum, but it's based on sound electrical engineering practice, and surprisingly my ex friend, Fugly the PC, had a similar sound problem as to what you're describing, which was fixed by untangling the spaghetti of wires behind the box along the lines I've mentioned. RF was the problem.

Of coure, it may not be the reason you're having difficulties, but it may be worth a try. If it doesn't fix it, then yeah, I'd give Applecare a call as Paul suggests.

Hope this may help

John

[drcarl]

Originally posted by Johnnyboysmac:

Try to keep your AC mains power lead separate from your signal, ie speaker leads, and also from other leads containing power, such as USB leads etc, although here I would think the amps flowing would be miniscule and unlikely to cause interference, unlike the AC mains lead.

This may sound like hokum, but it's based on sound electrical engineering practice, and surprisingly my ex friend, Fugly the PC, had a similar sound problem as to what you're describing, which was fixed by untangling the spaghetti of wires behind the box along the lines I've mentioned. RF was the problem.

John

I unplugged the power cord from the back of my iMac last night and then replugged this morning. Still get the clink sound.

I think that Johnnyboysmac has a great idea. Might take a while before I find the time to rearrange the mess of cables behind my desk, but I'll keep you posted as to whether it solved my problem.

[WJMoore]

Yeah I get the noises too, It's almost certainly interference from the power cable but I'm yet to be able to eliminate it.

Wes

[iLikebeer]

Just wondering if anyone ever figured out what causes that clicking noise. It's only noticeable when the room is very quiet; but when I do notice it, it drives me batty.