Buzzing Power Supply


SDAVE

macrumors 68040
Jun 16, 2007
3,381
435
Nowhere
Mine three. I don't think it did it during the first week when I bought it.

Should we be worried?
 

netnothing

macrumors 68040
Mar 13, 2007
3,662
297
NH
Just noticed mine emitting a slight buzzing sound.

The reason I noticed, is that I just bought the APC BX1300LCD UPS. I hooked it up to do some testing and noticed that while on battery power, the Mac Pro's power supply makes an even louder buzzing noise. Even tried the Mac Pro with a BR500 to see and it also makes the Pro's power supply buzz louder.

I do notice that even on regular power the power supply buzzes a little.

Does anyone else have a Mac Pro on a UPS that can test if there Mac Pro gets louder on battery backup?

Guess we shouldn't be concerned in general with the minor buzzing?

-Kevin
 

thxdave

macrumors member
Aug 10, 2007
65
0
Florida
Could the source of the buzzing (while on UPS) be caused by the lack of a completely smooth sinusoidal wave coming out of the inverter? I'm by no means an expert on this, but I was following a thread about this on a Mac audio site where they were looking for portable power ideas (location recording) and the experts there said that the power being output by the "usual" UPS units is not exactly clean and has a waveform that is less than ideal....good enough to run the gear but not as smooth as wall power or a better designed UPS source. Just an idea..... God help you if they are as noisy as the old blowhole power supplies.
 

netnothing

macrumors 68040
Mar 13, 2007
3,662
297
NH
Could the source of the buzzing (while on UPS) be caused by the lack of a completely smooth sinusoidal wave coming out of the inverter? I'm by no means an expert on this, but I was following a thread about this on a Mac audio site where they were looking for portable power ideas (location recording) and the experts there said that the power being output by the "usual" UPS units is not exactly clean and has a waveform that is less than ideal....good enough to run the gear but not as smooth as wall power or a better designed UPS source. Just an idea..... God help you if they are as noisy as the old blowhole power supplies.
Wow...most of that way over my head....but great thoughts.

I'm waiting to see if anyone else on here with a Intel Mac Pro can test whether they get the same results. Like I said, I never really noticed any noise out of the Mac Pro...but then again, it's always been on the floor. I do notice that while it's on street power, you have to get really close and almost behind it to hear the buzzing, however when I switch to UPS power, the buzzing is loud enough to hear without getting too close...that's the only reason I'm hearing it now.

I don't think my UPS is under powering the Mac Pro. The only things plugged in are the Mac Pro with 2 HDD's, 23" Cinema Display, Cable Modem, and a Linksys router. According to the LCD on the UPS, I'm only drawing around 230+ watts under normal load, and the UPS is only at about 27% load. I o notice that on street power, most of the time the unit is sending out 114v and on battery it sends out 115v.....both at 60.0Hz.

So I guess some questions for me and the original poster are:

1) How many Intel Mac Pro owners power supplies make a slight buzzing noise on street power? If so...where do you have to be to hear it?

2) How many owners power supplies get louder on UPS power.

-Kevin
 

Quad_Pro

macrumors newbie
Aug 24, 2007
13
0
MONTGOMERY, IL
I Think I Figured The Buzz Out!!!

I just moved today, well yesterday to be exact. Anyway I have a Mac Pro 3 gigahertz/quad. 2 gigs of ram. stock 250 hard drive. Anyway I just got done hooking up my unit and I noticed a buzzing sound coming from the top of the power supply on my beast. I also noticed the same buzzing in my apple cinema power supply. I was about to kill some one because my mac book has been in 5 times so far this year.

I have never had not one problem with my Pro untill now. Well I found your guys thread forums and was a bit releaved to hear I was not the only one this was happening to. The computer was fine before I packed up the moving truck and moved (15 miles) and yes i used the original boxes etc etc. I was very carefull how i packed the computer in the truck.

ok, i'll get to the punch line. I thought to myself if it was o.k. on the other end and making this noise on this end, then it has to be something on this end. Well i sat and thought and thought and thought and ripped out my hair and thought some more and that was when it dawned on me. We bought this house and are trying to save some money, so we put in all new energy efficiant bulbs ( you know the kind that look like they are a spiral) well sure enough, i turned all those off and all floresent bulbs and the buzz was gone. To be sure I tuned them all on and the power supply buzz came back even with the computer off. So i simply ran a heavy duty extension cord to the spare bedroom (had to drill through the drywall).

AND BOOM THAT WAS WHAT WAS MAKING MY SYSTEM BUZZ. I recomend if you guys don't have these bulbs, then look at what is plugged in around the computer. Go through the house and turn things off one by one (process of elimination).

GOOD LUCK, LET ME KNOW IF THIS HELPS ANY OF YOU.



forgive my typo's i'm in a hurry.
 

PatchMac

macrumors newbie
Oct 1, 2007
22
0
St. John's, NL
Same here, except I'm using an iBook G4, first time I heard buzzing was just now, so I came right away to check here if anyone else has experienced it. It's definitely louder when more juice is flowing through it. When you first connect the power and the light is green, it's hardly noticeable, but as soon as the light hits orange and the battery starts charging up, BUZZ BUZZ BUZZ.

I even tried plugging it into a very good power bar with surge protection, just to see if it would make a difference... hope it goes away, or at least I hope there's no risk with it.

In fact, even scrolling seems to affect it, I'll sit here, and as soon as I scroll, the pitch will increase while I'm scrolling... I don't like it.

Edit: And just as quickly as that... Poof, the buzz is gone... I gotta ask the guy who just got in what switches he flipped.. should be interesting.
 

SDAVE

macrumors 68040
Jun 16, 2007
3,381
435
Nowhere
Hi there, I get the scrolling buzz as well. Which power surge did you get? Can you tell me an exact model and name?

I am directly connected to the 3 prong wall outlet.
 

hanHans

macrumors newbie
Aug 29, 2007
14
0
Could the noise be caused by dust?
I just cleaned my video card, which had collected an immense amount of dust. It provided great results, my Mac now runs much more silent. I can’t even hear the video card fan.
However, there are still some noise left(like a faint buzzing sound), which I think comes from the power supply fan.
 

PatchMac

macrumors newbie
Oct 1, 2007
22
0
St. John's, NL
My Buzz was coming from the adapter part of the power cord, Plugging into my surge protector didn't accomplish anything

It was almost as if a power drain elsewhere in the house jarred the power (Or somehow in a very complex way changed the consistency of it) for my laptop. Could also be coincidence... I'm just glad I'm not buzzing anymore.
 

Sun Baked

macrumors G5
May 19, 2002
14,874
57
Florescent lights are really noisy lights, can play hells with computers when the ballasts are going out.

Most cheap UPSs with AVR use stepped sine output, might be noisier power for some and generally good enough -- but they are a heck of a lot cheaper than the pure sine UPS, which ups the cost considerably.

And when the UPS kicks on, it'll probably be loud as the inverter kicks on.
 

SDAVE

macrumors 68040
Jun 16, 2007
3,381
435
Nowhere
My Buzz was coming from the adapter part of the power cord, Plugging into my surge protector didn't accomplish anything

It was almost as if a power drain elsewhere in the house jarred the power (Or somehow in a very complex way changed the consistency of it) for my laptop. Could also be coincidence... I'm just glad I'm not buzzing anymore.
Then how did you get rid of it?
 

Hmac

macrumors 68020
May 30, 2007
2,128
2
Midwest USA
Mine buzzes too - annoyingly - and has since the machine was new. I assumed it was the power supply, ignored it. Then, after I installed Leopard, I found I could now control the power supply fan from the SMC fan control panel (coudln't under Tiger). When I bumped the PS fan speed, no more buzzing. Instead, I get the more white-noise-like sound from the fan, much lower volume. Interestingly, I note that when I boot into Windows XP, the buzzing is back - presumably since I can't control any of the fans.
 

SDAVE

macrumors 68040
Jun 16, 2007
3,381
435
Nowhere
Mine buzzes too - annoyingly - and has since the machine was new. I assumed it was the power supply, ignored it. Then, after I installed Leopard, I found I could now control the power supply fan from the SMC fan control panel (coudln't under Tiger). When I bumped the PS fan speed, no more buzzing. Instead, I get the more white-noise-like sound from the fan, much lower volume. Interestingly, I note that when I boot into Windows XP, the buzzing is back - presumably since I can't control any of the fans.
Oh yeah, under Windows XP the buzzing is worse!
 

SDAVE

macrumors 68040
Jun 16, 2007
3,381
435
Nowhere
I took my Mac in to the genius bar because of the PSU buzzing and the random pops in the sound cards line out, and the guy cannot reproduce it? What should I do? I want these fixed.
 

netnothing

macrumors 68040
Mar 13, 2007
3,662
297
NH
I took my Mac in to the genius bar because of the PSU buzzing and the random pops in the sound cards line out, and the guy cannot reproduce it? What should I do? I want these fixed.
Are these audible enough to be picked up by a camcorder....or a digital camera in video mode? That's what we did with a bad dishwasher that was making noise. ;)

-Kevin
 

Sandock

macrumors member
Aug 10, 2006
57
0
Calgary, Canada
Hey gang,
Does anybody else's Mac Pro power supply emit a buzzing sound? It's really annoying in an other wise quiet system.
Boy, I am relieved that I am not the only one annoyed by the buzzing sound from the power supply.

I have my MP set up in the basement; it is really quiet in there thus the buzzing sound is audible enough to be quite irritating sometimes.

I only noticed the buzzing sound when I added an extra hard drive. It definitely comes from the top part of the case where the power supply is.
 

peejack

macrumors 6502a
Aug 7, 2007
700
0
I took my Mac in to the genius bar because of the PSU buzzing and the random pops in the sound cards line out, and the guy cannot reproduce it? What should I do? I want these fixed.
But you didn't even notice it before this thread started did??

Come on guys stop being anal and enjoy your machines.
 

martinlk

macrumors regular
Jun 20, 2005
102
5
Aalborg, Denmark
Argh, I'm starting to become paranoid -- and I don't even own a Mac Pro yet.

I had similar problems with an iMac G5. Had to get it exchanged two times because it was emitting a high-pitched buzz/whine. It persisted even on the third one I got, but it wasn't as loud as the other two, so I settled with it.

Problem is that I sleep in the same room that I keep my computer in, so the machine must be totally quiet when powered off or in sleep mode (I mostly keep it in sleep mode). Do your Mac Pros "buzz" while sleeping?

That's what I miss most from the PC World -- the ability to just replace faulty/annoying hardware by buying standard components. If your PSU is noisy, you can just get another brand. Unfortunately it's not as simple as that on a Mac.
 

VanMan

macrumors newbie
Nov 1, 2007
19
0
Vancouver, B.C. CANADA
Mine too, intermittently...

My PSU buzzes sometimes. Sounds like a cross between a buzz and a high-pitch whine. There doesn't seem to be any obvious precipitating factor. If I put the computer to sleep then re-awaken it the sound is usually gone. No buzzing during sleep mode ever.