Q: My Mac Pro spontaneously restarts

Same for me. No restarts since I set it to never sleep. Still crossing my fingers tho' and I will try the Wacom updates too.

[Latest Mac Pro 3.33 GHz 6-core Intel Xeon but OS migrated from Mirror doors G4]

I'm doing the voodoo dance here, too. My Mac Pro rebooted 3x's thismorning. When I shook it or wiggled the plugs in the back, it wouldmake that trying to start sound while it was on. It was stable afterpulling the plug, making sure it's hard drives and cards were tight. Ihave my fingers crossed even while writing this message. Memory all OK.

Early 2008 Mac Pro Desktop, 2 x 3.2 GHz Quad Core Intel 

How many of you are using an Wacom and / or a 30 inch monitor? (I have both and noticed more of you mentioning these)

I'm using a Wacom Cintiq21. No problems with it all 2008, 2009, 2010. Just this year. Had the Cintiq since I got the mac.

I have one of the little Wacoms - Bamboo?  I have not had it hooked up during most of this but I do have the driver software installed.

Also, I have the smaller (24"?) Apple monitor from the early 2008 vintage as well as another 23/24". I would guess that   combination likely loads the DPU somewhat like the 30" would.

I do still have it set for the displays to sleep and so far that has not seemed to make a difference one way or another for me.

Well, I'm using a Wacom (a big Intuos 4) and a 30-inch Apple Cinema Display. Also a smaller second monitor. Both monitors use their own power supplies although I do notice the whole lot is plugged into the one power board. I might try plugging the CPU into its own powerboard. Despite mentioning the Wacom earlier my personal feeling is leaning back again to the Energy Saver prefs because in my case I have seen an improvement after getting into those prefs. By the way, in answer to your earlier post BobHassinger, I too have now unchecked the option to restart after a power failure.

On the not restarting automatically after a power failure - i think that is a good tool to use. It helps distinguish between the reasons for the problem. If it does not restart it went down mOst likely because the system sensed some sort of power issue. With auto restart for all conditions you can't tell which was the cause.

Here is another thing to compare notes on:

Is their any correlation between this problem and the use or non-use of power conditioning? 

I doubt the use of the simple surge protector stuff would make a difference, but at least some UPSs filter/smooth/condition the power into the computer. I noticed at least one case where one of these shut downs (or auto reboots) happened at just about the time something else nearby and on the same circuit i think acted like there might have been a very brief power dip or fluctuation. .

After that I added a smallish APC UPS. Between that and don't sleep I have not seen any shutdowns since putting them in.

(further testing here will have to come after power is restored - BIG impact here from a very unusual heavy October snow storm - 90% of my town has been without power for two days and may not get it for several more...)

This thread really came to my rescue over the past few days. So, now that I seem to have solved my problem, let me pass along the good vibes by seeing if I can help out anyone who might wander this way as desperate as I was.

I also have a question that I'm saving for the end.

My Mac Pro is a little older than most of the Macs discussed here:

Mac Pro 1,1 April 2007

Dual-Core 2.66 Ghz

OSX 10.6.8

Over the past year, I noticed my Mac was sometimes doing strange things while sleeping. Like occasionally freezing, or more recently, rebooting.

A few days ago, it began rebooting every few minutes and became unusable. So I went through all the pages of this thread, tried several things, and got immediate results only after doing the following:

1. Removing both RAM cards, taking out the RAM modules.

2. Removing as much dust as I could from that area of the computer, as well as the air vents. (I used one of those rubber bulbs you squeeze to shoot an air stream, and also my own lungs.)

3. Reseated the RAM modules

4. Replaced only the riser A (the Ram that came with the computer)

5. Restarted the computer.

Haven't had a problem since (almost 24 hours). Except for a kernel panic, which hasn't repeated or led to any other problems.

The solution seems too simple, but so far the difference is night and day. Things are normal again.

Now, a bit of mystery remains. I just tried replacing the second RAM riser with its two 512 MB DIMMS.

Everything's working fine, except that the additional RAM is not showing up in the profile. Instead, it shows those slots as empty.

So maybe that RAM is faulty, and maybe that was even the problem all along. Though those DIMMS did show up in the profile before I removed them.

One other thing. Others here talked about setting computer sleep to "never". So I did that earlier, and it's still set that way. Don't know if that's a factor or not.

Now a question for anyone who can answer it. One of the other responders here said: "I found that what triggers the re-setting behavior is a presence of ANY type of memory in bank 1 or 2 of Riser B."

So I'm wondering what to do about that. Should I try putting those two 512 MB DIMMS in the first riser? I know the standard instructions are to put the first set of additional RAM into the second riser.

Any thoughts?

I have had only one spontaneous restart, but a variety of weird instability problems coming and going. Tried everything except a new mother board. Maybe I'm on to something. I build an LG blu-ray burner in my Mac Pro a year ago. I worked fine though it keeps checking for disks every few minutes.

Now I read that someone with a Mac Pro and this particular model of blu-ray burner claims that it causes hardware troubles. Any of you have an LG BD drive build in, or connected?

It's too soon to tell after 24 hours if this optical drive was causing the problems but entering sleeping mode now goes much faster and without waking up spontaneous / immediately again. I'll keep you posted.

CDPlayer2, did you ever solve your problem of not being able to add memory to riser B? I've got the same issue. Had the auto-reboot syndrome and solved it by dusting the inside of my Mac and reseating the RAM.

Problem is, the computer no longer acknowledges having any memory in riser B, though a pair of 500 MB modules are actually present.

So I'm not sure what to do, as I'm down to only the pair of 1 GB modules in riser A.

I haven't done as much testing as you, so I don't if the RAM in riser B is bad, if the card is bad, or if there's something defective with that slot.

Have you found out any more about your situation?

Thanks!

(For a fuller description of my situation, see my comment on November 11 2011.)

Bruce,

Shortly after I posted, my Mac started rebooting again, even with memory only in riser A. As we rely on it for work, at this point I decided that I had enough and can't take any more risk, and bought a new Mac Pro.

Sorry couldn't be of much help.

-- Dmitri

I hear you, Dmitri. I haven't had it happen since the last time I posted, but when you're on a deadline, you can't have that kind of thing occur. I'm thinking of getting a pc and putting photoshop on it just as an 'in case'. They never seem to have these issues. Don't know how I'd get the pc to read an external drive, though. Have to look into that.

Dmitri, thanks for getting back! I'm still OK after a few days, so I'm hoping my situation is different.

Bruce

Regarding reading mac drives on PC, I can vouch for MacDrive (http://www.mediafour.com/products/macdrive), which worked for me in the past.