Weird electricity noise when scrolling sidebars or dock

[mfzb10]

I was using my newly installed hackintosh and I started to hear some weird `kind of electricity´ noise when I scroll the sidebars of SAFARI or move the cursor around the dock.

the sound is proportional to the mouse´s movement. I also notice the noise when the system is thinking.

I thought it came from my speakers, so I turned them off... and now the sound seems to come from my computer case... only quieter, what I mean is that the speakers only enhance the sound level but they are not it´s cause.

I used to hear this sound too when I had windows 7, but a lot quieter, and I´m pretty much sure that It disappeared when I turned my speakers off.



If you wonder how the noise sounds like.... the best description I can give you guys is that it sounds like when the old Hard Drives were thinking and the red led of the computer cases turned on... that old hard drive electricity sound...

I don´t mean my HD is the cause of the noise cause the sound appears when the red led of the computer case is off.... it just sounds when the system thinks or when I scroll the sidebars or dock.

 

[zarac]

Sounds to me like you're having a Ground loop (wikipedia link).

This can be caused by bad PSU unit, bad motherboard positioning, bad electrical wiring etc.

Here's a page that explains the problem in detail and offers solutions:
Ground Loops and Power Problems

Threre are some users on Apple forums suffering from the similar problems - nice discussion with some good advices (link)

Hope this helps you get rid of the hum.
Good luck.

 

[powerpcg5]

It's not a ground loop. (otherwise, you'd be hearing 60Hz/120Hz hum all the time).

It's EMI/RF Interference. (Radio Frequency Interference)
http://en.wikipedia.org/wiki/Electromag ... terference

Your computer cases probably doesn't have good shielding. (i.e. too much plastic parts?)
-- more prevalent on cheap cases.

You can try grounding the metal parts of your case (i.e. basically, making a faraday cage... so RFI don't get in or out of the equipment).

You can try using ferrite beads
http://en.wikipedia.org/wiki/Ferrite_bead
Where to actually place them will be trial and error. Depends on your setup and circumstance. i.e. This EMI/RFI is borderline like voodoo magic. Try power lines, data lines, etc.

 

[stuckwithme247]

I am having a similar problem on my computer. I happens mainly when I am scrolling, and only on OS X, not Windows. Don't understand how it could be the case because the keyboard and mouse are plugged directly into the motherboard, which is connected to the power supply. The only connection to the case is that the mobo lies down on it...

 

[Bratko]

I had same issue and it was indeed ground loop. I have audiophile 192 sound card and Mackie RM8 monitors that were connected with 1\4 unbalanced (mono)cables that worked fine on my win box without any issues whatsoever. Since I build mac box and put same card and same speakers in use experiencing same weird noises as described here I thought it mast be one of the component that is faulty. Anything I tried failed including using on-board sound and speakers even headphones. After few days of trying every possible damn thing I gave up and was ready to return MB for replacement since that was only thing I could not take apart and just before disassembly I thought of putting DI box (that was sitting on my desk all this time) between sound card and speaker just for a sake of trying and noise magically disappeared. Then I disconnected my speakers and used headphones only just to discover no noise. Solution for me was very simple if I tested rig using only headphones to begin with. I used new unbalanced(stereo) cables since my sound card and monitors support such connection and everything is working fine with crystal clear sound.
Cause for ground loop can be other external and in some cases internal connections so I will suggest this steps for troubleshooting:

1. Connect headphones to internal sound card so you can confirm that you have noise present in the headphones.
2. Physically disconnect all external connections leaving only keyboard, mouse, monitor and headphones connected and at this point most likely there will be no noise. If you still have noise present than it is inside the case and if that hapens I would remove all connectors from motherboard like additional USB ports on the box etc.
3. Connect one device at the time to see which one is causing the noise.
4. Troubleshoot that particular device since some are easy like mine(stereo cables instead mono for each channel) and some will need other approaches.

While this may not be solution for all the cases it is something that I experience first hand so I am sharing it in hope it may help others as well since this is quite often problem builders have.

Good luck.

 

[SkyHolzinger]

so the big plastic window on my corsair case could actually be letting in EMI/RFI. Which is why my podcasts sound like there are techno birds chirping in the background? sigh.

UPDATE: Still haven't fixed it. I heard similar issues used to happen on windows/DOS systems because of IRQ conflicts. Then I read OSX supposedly automatically fixes IRQ conflicts. I'm going to try the method below to narrow down the source.

 

[bucket772]

anyone have any more updates?

 

[yusz]

I experienced the same issue and it was the mobo that was faulty. Got it change under warranty and no issue so far.

 

[bucket772]

does it happen all the time or is it intermittent? sometimes mine will make the noises when I'm scrolling and sometimes seemingly at random

 

[Ashbel]

I'm Having the same issue, has anyone sorted this out?
Even when I Play a video from Youtube I keep hearing disturbing noises behind