Mysterious SL shutdown

[jayducharme]

I have 3 Mac Minis (2008 models) controlling three lobby display monitors. They each run continuously day and night. The monitors cycle on and off at preset times. They've been running fine for three years. I just upgraded them to Snow Leopard. Now at some point every night, all of the Minis turn themselves off, a complete shutdown. The energy saver setting is turned off. I can't figure out what's going on. Any ideas?

 

[mainstay]

Are the mini's attached to a UPS?

If so, does the problem persist when the USB<>Data line is disconnected?

Can you catch WHEN at night (perhaps use LogLeech to determine shutdown times)?

Do you know if they are proper shutdowns or sudden loss of power shutdowns?

New cleaning lady using the outlet for her vacuum? (only partially kidding here).

When I first read the title I thought "heat problem" but 3 mini's all at the same time... hmmm.... unless they are all in a really hot room together.

Check ventilation.

If you check "automatically startup after a power failure" in power settings, any change?

How are the monitors told to power cycle? Could they be accidentally powering off other devices attached to the same circuit? (I'm thinking of a programmable power outlet)...

Are there any other devices also losing power? Staff reporting, "yeah, and the microwave keeps resetting to 12:00"... that sort of thing which suggests a breaker blowing... or a switched wall socket.

Just some thoughts.

 

[jayducharme]

There's no UPS attached. The Minis are plugged into a wall jack. The area for all of them is cool, so it's not overheating. As I mentioned, they ran fine for three years; they began misbehaving only after the Snow Leopard upgrade. (They originally had Leopard installed.) I had thought of power spikes or the power going out, but the monitors would have reset as well (since they're in the same outlets). But the monitors keep working normally. I didn't know if there was some setting in SL that shut the computer off if the OS didn't detect monitor activity for a certain amount of time.

 

[Quad5Ny]

pmset -g in Terminal

If that doesn't show anything, check Console for events around the time they shutdown.

 

[jayducharme]

I hunted through Console's log and found a few things that repeat before each shutdown: Time Machine was inadvertently turned on (with no backup drive connected) and kept failing to find a place to backup data. The only other thing that seemed to keep happening before shutdown is Adobe Acrobat Pro 9 was trying to update. I've turned off both of those; I'll know tomorrow if it did any good.

 

[jayducharme]

Well, one of the three Minis has continued operating flawlessly. The other two turned themselves off again. One of them runs a Flash demo; Console reported that the demo crashed for an unknown reason. Also, I had shut Bluetooth off (That Mini controls a kiosk, and students discovered they could control it with Bluetooth devices), but Bluetooth on the Mini keeps turning itself back on. Weird.

 

[jayducharme]

The mystery has been solved. Embarrassingly, it was Scheduler (in Energy Saver). The odd thing is that I never turned it on. I have no clue how it was activated.

The continual crashes were indeed from Adobe's CS5.5 suite. When I went back to CS5, the crashes stopped.