Possible coil whine in my nMP

[MMcCraryNJ]

Yeah, I'll post an update once it's been running for a week or so and I know if there's any noise under different workloads. The one I exchanged was running silent half the time and then making the noise the other half of the time and it didn't seem particularly workload related, except that I think that when the fan is running harder, it amplifies the noise. I'm still mostly positive about the nMP, but between the noise issue and graphics card problems I had before, I've come to the conclusion that you have to be prepared to nag Apple support until they fix problems and you also need to keep your AppleCare current.

Any update on your machine? Still silent?

After two weeks, my new machine (which was built January of this year) is still producing the "coil whine" noises (one noise when moving the mouse pointer across the screen, another when there is any sort of network activity, although both might be related to the same issue), and I also have a low howling noise when the fan is at its default idling speed. I called AppleCare and got on with a senior advisor, who noted everything and made an appointment for me at a local Apple retail store. Since I did not purchase my machine direct from Apple, they cannot outright replace it with a new one, at least at first. They are going to attempt to repair it first, and I was told a new replacement would be an option if they cannot repair it.

So, that's where I'm at with it now. My appointment is tomorrow, so I'll keep everyone updated.

 

[edanuff]

Any update on your machine? Still silent?

The new machine does occasionally make some noise but I have to listen very closely for it since it's nowhere near as loud as it used to be and doesn't happen often. If I weren't sensitive to it from the previous machine, I probably wouldn't notice at all. So I'm considering the problem solved for now, but if it comes back to noticeable levels I'll contact support again. The other thing I did that might have also helped was to replace the ethernet cable with a shielded ethernet cable with shielded connectors at the same time I got the new machine, since it seemed the noise corresponded to network traffic.

 

[MMcCraryNJ]

The new machine does occasionally make some noise but I have to listen very closely for it since it's nowhere near as loud as it used to be and doesn't happen often. If I weren't sensitive to it from the previous machine, I probably wouldn't notice at all. So I'm considering the problem solved for now, but if it comes back to noticeable levels I'll contact support again. The other thing I did that might have also helped was to replace the ethernet cable with a shielded ethernet cable with shielded connectors at the same time I got the new machine, since it seemed the noise corresponded to network traffic.

Thank you for the update, it's good to know that while most units will produce some self-noise, some are indeed louder than others and that the issue is something that can be fixed, rather than my ears just being hyper sensitive. I work in pro audio production, and with the machine located 3-4 feet away from me on a desk, I was clearly able to hear the fan at no load and the two coil whine sounds, and it's very distracting when working. Some were speculating that it's an issue with all Ivy Bridge systems, however I have my 2012 non-Retina Macbook Pro about 10 inches from my face and comparatively speaking, it's dead silent until I stress it enough to have the fans kick up. I would think that my Mac Pro should offer the same noise levels, and that it's pretty unacceptable how much louder it is than my Macbook.

The Genius Bar has my machine now. They checked it in for testing, so that they could take it into their quiet backroom and see if they can locate the part or parts that are making the sound. They also had me e-mail them the multiple audio recordings I made of each sound so that they can better identify them. They made very detailed notes while I was dropping it off too. Now I'm just playing the waiting game, hoping they can clear this up on my 2 week old machine.

 

[random-uk]

@MMcCraryNJ could you post the recordings you made somewhere so I can compare to mine?

My current update is they have replaced the power supply, then they replaced the fan and now they have the machine again. None of which fixed the problem.

The joy of being without my production machine for over a month now.

 

[edanuff]

They also had me e-mail them the multiple audio recordings I made of each sound so that they can better identify them. They made very detailed notes while I was dropping it off too. Now I'm just playing the waiting game, hoping they can clear this up on my 2 week old machine.

The recordings are the key to getting it resolved. They were never able to reproduce the sound themselves. There is apparently a technote they have access to that says that coil whine is caused by environmental issues like noise on the electrical lines or bad cables, which is why I replaced all the cables and plugged into a electrical filter just to be sure.

 

[MMcCraryNJ]

@MMcCraryNJ could you post the recordings you made somewhere so I can compare to mine?

My current update is they have replaced the power supply, then they replaced the fan and now they have the machine again. None of which fixed the problem.

The joy of being without my production machine for over a month now.

I will post the sounds a bit later, but sure.

Update on my machine: Genius Bar returned it to me this afternoon. The tech said that they replaced both the fan and logic board, however they could not reproduce the sounds at all, even before they replaced the parts. They analyzed my recordings and everything. Tech admitted "We don't exactly have access to a truly quiet backroom here, sooo". That didn't fill me with any sort of confidence.

Got my computer, went home, plugged it back in, and....noise issues still persist. All of them, including the fan, which isn't even the annoying part. I could live with it, if only my computer didn't squeal every time I moved my mouse or downloaded a file.

At this point, I'm at a loss. This Apple Store is 20 miles away from my house, so two round trips is an 80 mile drive, plus the time spent without my machine and downtime from my clients.

I have the contact information of the senior tech who helped me over the phone, including an extension. Going to give him a call tomorrow and see what we can do, but in the meantime I'm going to try to eliminate every possible cause on my end...going to go buy a new mouse tonight, and even though I have a Furman Power Conditioner which eliminates dirty power noise from the AC line, I'll invest in a UPS with EFI/RFI shielding as well. I'll bring it to someone else's house if I need to as well, to make 110% sure the issue isn't on my end. To reiterate, I have tried plugging into multiple outlets in my home, multiple surge protectors with and without power conditioning abilities, tried my mouse in different USB ports, including a USB hub, etc.

Very disappointed right now. My 2012 MacBook Pro with the same stuff plugged into it, with the charger plugged into the same outlet, is dead silent. I'm not going to live with anything else for a machine that cost twice as much.

 

[random-uk]

Oh man I'm right there with you.

So update on mine: they thought they had tracked it down to a capacitor on the riser board. They replaced that but it didn't solve the problem. Am waiting to hear back on how they are proceeding.

Just to put your mind at ease maybe a little, they agreed with me that they could hear the noise. I was very specific saying they would need to go to a quiet room.

 

[Average Pro]

I recently traveled from the US to Korea and brought along the R2 unit (nMP). Korea runs on 220V / 60 Hz. As that falls within the operating values of the nMP, I plugged it straight into the wall. Note that some of the outlets in Seoul have the American style 3-pronged plugs (with large text indicating 220V) so you don't need an adaptor. Everything worked fine, but I suddenly noticed the noise described in this forum. To test my theory, I used a step-down transformer (110V). Guess what? No more noise.

Hope this helps someone.

 

[h9826790]

I recently traveled from the US to Korea and brought along the R2 unit (nMP). Korea runs on 220V / 60 Hz. As that falls within the operating values of the nMP, I plugged it straight into the wall. Note that some of the outlets in Seoul have the American style 3-pronged plugs (with large text indicating 220V) so you don't need an adaptor. Everything worked fine, but I suddenly noticed the noise described in this forum. To test my theory, I used a step-down transformer (110V). Guess what? No more noise.

Hope this helps someone.

Interesting found, thanks for the sharing, just wonder will that make any difference on the cMP PSU.