Home Forums Hardware Mac Desktops & Notebooks Sleep issue: G4 MDD

We've got this MDD G4 tower which under Energy Saver is set to sleep the display and sleep itself after 15 minutes of no activity. This short interval is because it's so NOISY.

All went as set, for the first few weeks.

Now, the display goes off but the NOISY tower does not go to sleep until we tell it to, from the Apple Menu. We do this because it's so dammed NOISY, or did I already say that?

So, what's going on? Is this something I should worry about? I just rebooted it - it is usually left in Sleep Mode overnight i.e., left on but asleep as a usual modus operandi, after the previous crisis with the previous G4 tower which was deadded by a power cut some weeks ago.

Thanks........

Try resetting PMU. As you'll see from that link, PMU affects sleep, among other things. A power surge or outage can cause PMU to become wonky.

Thanks Jon, but (as I said) it was the previous G4 which got deadded by a power cut. We have had no power cuts since installing the MDD.

I really, really, (does saying really twice make it more really?) don't want to revisit that route unless I really really have to. There must be something else awry. Personally I think it's just because it's a MDD. If I'd known then what I know now, I would never have bought that model, but it's the only glitch so far, apart from the NOISE.

If memory serves, PMU also regulates the fans, so it might be worth a shot. I also recall that the MDD was called, somewhat less than affectionately, "wind tunnel". You don't have to have a power outage to screw up PMU; a power surge will do nicely.

The combination of the noise (fans, presumably) and the fact that the machine will no longer sleep automatically suggests that there may be some active software process ongoing, which ties up the CPU(s) (hence the fan noise) and prevents sleep.

You might try launching Activity Monitor (in /Applications/Utilites) and setting the display NOT to sleep for the duration of this experimentation. In the Activity Monitor window (invoked, if it's not already showing, by typing Command-1 or by choosing Activity Monitor from Activity Monitor's Window menu), click on the CPU column heading. (If the little triangle next to CPU is pointing up, click the heading again to reverse the list from ascending to descending order.)

Now sit back and "monitor" the "activity." Do you see any process consistently using a CPU percentage well above the single-digit "background noise" of other open applications?

Two results:

1. Some 6th-sense instinct made me look at the situation that computer is left in, when it refuses to go to sleep on schedule. The same instinct made me suspect Appleworks (again - see posts passim).

When that Mac is left with AW as the active program i.e., running on the screen, not "active" as in there's a pointer on the Dock, it will not sleep as scheduled. All I did was to click to Finder, make that the "front" program/app, and it went to sleep as it should. This shuts the NOISE OFF.

2. On another Mac, I had a go at Activity Monitor as you suggested, intending to try your route. YeGODS! I was hardly doing anything, yet there is so much silent activity going on there, most of them "root" inscrutable things. I had no idea. I thought if you're not doing anything, the Mac ain't doing anything either but that's clearly not the case. It keeps checking things, doing things, little tiny beyond-my-ken things which no doubt make sense to it. Spooky.