Small buzzing sound coming from back of Mac Pro - Is this normal?

You're welcome, glad I can be of some help. I got the phone call this morning from Amsys Apple Repair Service, which is (as their title states) an Apple repair service that Apple deals with directly for fixes. I found the time it took them to call me was rather quick, i wasnt expecting that call considering that things in London have been rather slow especially with mail and banks. Well, anyway they will arrange a collection of my machine tomorrow morning so I'll be staying home all morning and hopefully they will fix it and bring it back in no time. If they CANT fix it, which i HOPEFULLY doubt because it seems so minor, I will just have to get a replacement machine.

Will keep u all informed on what happens next!

Ok, Amsys Repair Service came by this morning to collect my Mac Pro. They anticipate that I'll get it back all fixed up no later than Friday of next week hopefully. Will keep u all informed on what they say if they need to call me.

Received a call from Amsys just now. The techguy said that my PowerSupply of the MacPro is definitely faulty and they will change it. Though they're not sure what the problem with my speaker popping problem is. Since it's a built-in soundcard then there's no other way but to change the ENTIRE logic-board, at which point i might as well just ask for a new MacPro. But I'm just afraid that by getting a new one, it could still have the EXACT same problems as my last one or maybe even MORE problems!! ...I'm just going to sit this one out and ask them to repair it and if the problems haven't been rectified or come back and worsen over the months, then at that point I'll ask for a brand new one since I have extended Apple Care.

Seems nowadays the more money u spend on a machine, it's just another way of saying that this machine will be riddled with problems and the beauty of our modern tech society is not to enjoy the experience and the technology, but rather getting it to work properly the way u want it to...What ever the **** happened to "it just works!" or enjoying the user-experience (Apple's moto)??

Yes he checked and said that the sound it was making wasnt normal, so he suggested a change in my PSU. He thinks i should get it back in the next 2-3days, he just has to see what the issue is with my sound popping dilemma, and my Airport Extreme WiFi card. So if not end of this week, definitely beginning of next week.

But my advice, TAKE IT to Apple repair, or if necessary, ask for a new one. But if i were u I'd ask for a change in faulty parts, since getting a new one might have even MORE issues than your first machine...u never never know! But even after repairs the problems persist, then ask for a new one. That's what I'm going to do.

I have the same buzzing PSU issue, have already had 2 replacements (so 3 different Mac Pros) all with the same buzzing. I have an appointment at the genius bar at the Apple store to get the PSU replaced. I also have cracks in my speakers whenever someone turns on/off certain things in other rooms, especially the kitchen.. I don't know what to do about that.. and I also have a slight but very a annoying sound coming from the GPU fan that sounds like someone blowing into an empty bottle :/....

Wow, sounds like you've had a rough time. I just hope that my PSU replacement fixes the issues. I don't know what an appointment at the 'Genius' bar will do to help to be honest. What are they going to do that is so different and beneficial? Not trying to put u off or anything, but I can be rather pessimistic about these things.

I don't have that GPU fan sound problem though. And as for the speakers popping sound problem, it doesnt happen whether i turn on/off certain things, even as i'm seated without touching ANYTHING else but my MacPro it still happens, i live in a one-bedroom flat so no one else is here but me.

What do you mean? I got the Genius bar appointment so they could replace the PSU. Are you suggesting to just do a quickdrop instead? Also, I'm really scared they'll scratch my baby when fixing it (I'm a bit OCD when it comes to scratches etc.)

In your case, are you sure other people's flat's electricity doesn't affect yours? :/ has anyone here tried if the crackles in speakers still happen when using the optical out or an external USB sound card?

I'm extremely OCD when it comes to scratches and nicks as well when it comes to anything let alone my MacPro. And no i wasn't suggesting anything, i was merely saying that since u got a number of replacements, what could a visit to the Genius bar possibly do other than the same old thing?

Anyway, I don't know whether or not other people's flat's electricity affects me or not, not really an electrician. And as for external soundcards, no, I think I've spent enough money on this machine to have the performance and convenience to my liking and beyond. What does Apple expect? That in order to not have any annoying ticks that our electricity should be more than perfect? I had a custom-built WindowsPC and it never had ANY of these issues, especially not with sound, it did have other problems but that's because of the OS itself and some hardware issues, but nothing about sound or if my lights were on/off at that given time which might cause sound popping. This is new! seriously. And that custom PC had a 1000watt PSU, probably more than what the MacPro has in it.

I mean, my Macbook Pro mid-2009 doesnt have any of these problems either. it's simply strange. well, I've said enough about this, when i get it back, if there are still problems, i'll take it back and ask for an exchange, if there are STILL problems, then I'll just fight for my money back in that case, what a shame, truly a shame...

Well what I think is happening is that I had 3 Mac Pros with the same make and batch of PSUs, maybe if I get the PSU replaced (not the whole Mac Pro), I'll get a different batch? It seems to have worked for someone on macrumors, his replaced PSU doesn't buzz anymore, it does make a high pitch noise though.

You mean he got rid of the buzzing noise, but his speakers produce a high-pitched sound now? Like the popping noise on my speakers isn't enough. this is brilliant. thanks for the info. Will keep u all updated on when my MacPro comes back, something tells me I'm not going to be satisfied.

No, I don't think he ever had the speaker problem, only the buzzing PSU.. and getting the PSU replaced got rid of the buzzing, but the new PSU makes a slight high pitch noise. Maybe that's normal though.

If this high pitched sound is noticeable from where i sit (roughly 1m across my MacPro), then it will mean that this PSU is faulty as well unfortunately. But if i have to literally place my ear next ON the MacPro's PSU (dangerous i would say), then i suppose it's normal.

These forums are very helpful-- the buzzing sound has been driving me nuts. It is not loud but noticeable. After reading the advice here, I pressed on the side panel in various places. I found that if I pressed the bottom of the panel, below the apple logo, the buzzing went away. I will try reattaching the panel or using tape.

Thanks! Now I know what the cause of the buzzing is.