Refurb 2012 Mini Buzzing Noises

[revz789]

Hello! First post here. Hope I can get some help on this.

Recently bought my first Mac Mini, a 2012 Refurb, 2.3 i7, 16GB, 256 SSD. Pairs up really nicely with the 27" Apple Thunderbolt Monitor.

Every few seconds though, it makes a slight buzzing noise. Not super loud, but definitely audible in a somewhat quiet room or if the TV is at normal volume. When it starts, and I'm on a web browser, it continues until I scroll up or down, or click on a link loading a page. Then it goes away until a few seconds later where it will start again. Weird, right? Never heard anything like this before. Definitely not an internal fan or an external physical thing like the desk or something rattling. Or else it probably wouldn't stop and start with my software interactions. It's not a volume dependent thing as I hear it both when the audio is muted and at full volume. I can't pinpoint to where it is coming from, even when putting my ear right up to the mini. Sound happens both when the mini is in vertical or horizontal orientation. If anyone has ever heard of anything like this, please feel free to chime in.

I do have more tests to run though. I'll try moving the entire system to another room in the house, switching monitors, moving the mini as far away from the monitor/keyboard/user as possible, listening for sound in different applications, etc. I'll update when I can. Thanks!

 

[Boyd01]

Where did you find a "refurb" 2012 Mini? Apple has not sold them for years. Do you mean "used"? Apple's refurbs have the full one year warranty, just like a new one.

I have 2012 quad just like yours but mine is the 2.6 ghz model. Never heard anything like you describe from mine.

 

[revz789]

Can only Apple sell refurbished Minis? Third party store sold it as "seller refurbished" but I guess could also call it "reconditioned" or "used and fixed up". Also came with a one year warranty so all the same to me, really.

I don't think the problem is endemic to the particular model or batch or anything. I've done searches and some people describe the problem in various computers, ranging from issues involving power supplies to radio interference to circuit boards or even software related. Wish I knew because although I can ignore it 99% of the time, the other 1% drives me nuts. Not really because of the sound, but because I can't figure it out and I hate not knowing haha.

 

[Chuck Rodent]

Maybe some part or screw is not tightened inside the box. If you are comfortable with opening it up, remove the bottom plate and push on the memory, antenna plate and fan cover. I bet it is one of those, and can be fixed with tightening the screws. See the iFixit instructions on the 2012 Mac Mini HD replacement to view what the internals are like, you probably don't have to take anything apart to figure out what is buzzing.

 

[ActionableMango]

Could be buzzing capacitors.

 

[revz789]

Maybe some part or screw is not tightened inside the box. If you are comfortable with opening it up, remove the bottom plate and push on the memory, antenna plate and fan cover. I bet it is one of those, and can be fixed with tightening the screws. See the iFixit instructions on the 2012 Mac Mini HD replacement to view what the internals are like, you probably don't have to take anything apart to figure out what is buzzing.

Thanks for the idea, I think I will open it up and just take a peek inside, make sure there is nothing obvious. I doubt it's the problem as it isn't an uninterrupted or totally random sound, but rather a predictable one every few seconds and it responds plus gets louder when I interact with the screen. The sound is electronic-y. But it won't hurt to do a quick physical check. I'm a bit shy about opening it up but then again, if I'm comfortable with opening up my iMac, this probably is around the same ballpark.
[doublepost=1515524620][/doublepost]

Could be buzzing capacitors.

If were to bet on what it would be, this would probably be it. It's the only explanation that makes sense, besides possible radio or other signal interference somehow being audible. Is there anything that can be done about this? I'm guessing not short of replacing a logic board or something. I'm all ears with any ideas though. Thanks.

 

[treekram]

If there were a widespread issue with logic board capacitors, we would have heard of it before. So before going on a possible wild goose chase of trying to find a buzzing capacitor, I would look at the RAM and SSD first. If they are econo parts or if the RAM doesn't have the right spec, that could be an issue. You can find out the manufacturer and (usually) the part # by using the System Information app.

EDIT: Also, the Mini has a wi-fi/bluetooth card and if nothing else works, you can try removing that to see if it makes a difference ("disabling" wi-fi via the System Preferences app doesn't necessarily do that so you can't rely on that). Also, when I took my Mini apart, on the antenna plate (the large metal grate visible when you take off the cover), I couldn't easily put back one of the screws so I didn't. I don't have issues but that maybe something to look for.

 

[ActionableMango]

If were to bet on what it would be, this would probably be it. It's the only explanation that makes sense, besides possible radio or other signal interference somehow being audible. Is there anything that can be done about this? I'm guessing not short of replacing a logic board or something. I'm all ears with any ideas though. Thanks.

I've had buzzing capacitors and your description reminded me of my problem because, like you, the buzzing only occurred with certain activities.

If it is a capacitor, I don't have any good suggestions. Component-level replacing of capacitors would probably fix it, but is not practical at all. Perhaps a line conditioner (power conditioner) or an online UPS might help, but that's just speculation and would be expensive just for a test.

So hopefully the problem lies elsewhere and one of the other suggestions pans out.

 

[revz789]

If there were a widespread issue with logic board capacitors, we would have heard of it before. So before going on a possible wild goose chase of trying to find a buzzing capacitor, I would look at the RAM and SSD first. If they are econo parts or if the RAM doesn't have the right spec, that could be an issue. You can find out the manufacturer and (usually) the part # by using the System Information app.

EDIT: Also, the Mini has a wi-fi/bluetooth card and if nothing else works, you can try removing that to see if it makes a difference ("disabling" wi-fi via the System Preferences app doesn't necessarily do that so you can't rely on that). Also, when I took my Mini apart, on the antenna plate (the large metal grate visible when you take off the cover), I couldn't easily put back one of the screws so I didn't. I don't have issues but that maybe something to look for.

Thanks for the suggestions. I will take it apart tonight and give everything a quick once over, make sure all the screws and parts are as they should be. Wouldn't hurt as long as I put everything back to spec.

I've had buzzing capacitors and your description reminded me of my problem because, like you, the buzzing only occurred with certain activities.

If it is a capacitor, I don't have any good suggestions. Component-level replacing of capacitors would probably fix it, but is not practical at all. Perhaps a line conditioner (power conditioner) or an online UPS might help, but that's just speculation and would be expensive just for a test.

So hopefully the problem lies elsewhere and one of the other suggestions pans out.

After exploring the inside of it, my next step will be to purchase a UPS of some sort. I needed one anyway so not a problem. I'm also going to be troubleshooting all the variables so yes, hopefully something simple solves it. I can live with it but it would be nice to get rid of such an annoyance. Thanks.