Tuesday, February 26, 2008

Quick Apple tip

I had found that, within the last week or so, my normally near-silent Mac Pro had started to develop a weird glitch: every couple of minutes, all of the fans would suddenly power up to full for about 30 seconds, and then power down again.

I wasn't unduly worried since everything appeared to be running at a reasonable heat and performance seemed unaffected. However, I thought that I would try to hunt down whether or not this was a known problem—with the recent incremental upgrade I had performed, for instance—and if there happened to be a fix.

As it happens, there is: you need to reset the System Management Controller.
The System Management Controller (SMC) is a chip on the logic board that controls all power functions for your computer. If your computer is experiencing any power issue, resetting the SMC may resolve it. The SMC controls several functions, including:
  • Telling the computer when to turn on, turn off, sleep, wake, idle, and so forth.

  • Handling system resets from various commands.

  • Controlling the fans.

There are a couple of ways to do this, but the simplest—in other words, the one that doesn't involve you stabbing at the motherboard with a pencil—is the following method.
To reset the SMC on a Mac Pro:
  1. From the Apple menu, choose Shut Down (or if the computer is not responding, hold the power button until it turns off).

  2. Unplug all cables from the computer, including the power cord and any display cables.
  3. Wait at least fifteen seconds.

  4. Plug the power cord back in, making sure the power button is not being pressed at the time. Then reconnect your keyboard and mouse to the computer.

  5. Press the power button to start up your computer.

My Mac Pro is now back to its usual near-silent operation. The method for resetting the SMC or PMUs for other models of Mac can be found under point 9 in this article.

UPDATE: I spoke too soon. Whilst the brief period of shutdown cooled the machine sufficiently to gain a reduction in noise, it soon started up again. I tracked it down to the video card fan, which was going like the clappers.

After performing a hardware test (no problems) and then running the machine with the side open to ascertain that the main fans were all running correctly, I took a look at the Radeon graphics card. Why didn't I think of doing so before?

The air input for the fan was solidly clogged with dust and other crap (not least, the ash and smoke from about 5000 cigarettes, I'd imagine). As such, the fan was having to spin ten to the dozen to pull any air over the components at all. So, after removing the graphics card and cleaning the entry to the fan airway (I'l need to go and buy a new toothbrush!), I replaced the card and the machine is now absolutely silent.

Now I'll know what to do next time that happens...

UPDATE 2: for the usual commenters, here is the "official" description of our old friend, Artie MacStrawman.
Mac users will remember MacStrawman as the Mac user who:
  • Says the Mac is utterly invulnerable to any and all malicious attack.

  • Mindlessly worships Steve Jobs.

  • Blindly buys anything Apple releases no matter how dumb and stupid and dumb it is.

  • Refuses to accept that Windows might be better at anything. Even being Windows.

  • Emails death threats to anyone who disagrees with him.

Daring Fireball's John Gruber said "I just wish that guy’d switch to Windows or Ubuntu or something.

"But... he's Artie MacStrawman. So I guess that’s not going to happen."

I would also like to add that Artie MacStrawman also maintains that Macs never, ever go wrong (in defiance of all physical laws) and that Macs never, ever need a tune up or a bit of desultory maintainence from time to time.


Mark Wadsworth said...

Ye olde Mac Mini does tend to get a bit warm, so I took the simple expedient of placing it on some small objects so that there is ventilation all the way round.

One thing pisses me off though, I bought the MS Office for Mac (the Neo Office is very good but not quite good enough!), and when you are in Word, you can't expand the window to fill the whole screen, it is restricted to about two thirds of the screen so it's a bit difficult to read. Is there any way to fix this?

freetherider said...

Good old user-friendly macs eh?

Michael said...

Macs: work straight out of the box do they?

Mark Wadsworth said...

Straight out of the box - from peeling off the sticky tape to my first post was twenty minutes.

Devil's Kitchen said...


yes, they do. This machine is over a year old. Further, as per my update, the actual issue was with the Radeon video card.

Mark, if hitting the green button on the top left of the window doesn't work and dragging the window from the bottom left doesn't work, I don't know what else to suggest. I've never looked into it since one of the things that I hate about Windows is the way in which application windows fill the screen.


Anonymous said...

It's absurdly easy to resize or minimise Windows application windows - but why bother when you can flip between them by clicking the relevant tab on the taskbar? If you absolutely must see the desktop, just click the 'show desktop' icon, bottom left, next to the Start button (it is on mine anyway).

Mark Wadsworth said...

Compare and contrast the following factoids:

"About 5000 cigarettes"

"This machine is over a year old"

Hint: 5000 ÷ 365 = 14.

Devil's Kitchen said...

Well, originally, I went for 14,500 cigarettes (40 a day over a year) but then I realised that I didn't smoke all of them in the flat. Although, I do smoke most of them in the flat, come to think of it...


Anonymous said...

For a fashion statement it seems remarkably reliable....It's a bit like eye shadow on blokes though, isn't it?

Anonymous said...

For all the culto gibberish, friends with Macs have an awful lot more serious problems than I do with my dirtcheap PCs.