My Mac Pro spontaneously restarts

Over the last couple weeks my computer has suddenly and repeatedly restarted itself without warning while I was using it. It's as if the power was flipped off for a fraction of a second. I checked the power cables, of course, and they're fine. My house has good electrical and no other appliance has behaved like this.

What possible trouble could this behavior indicate? I'm making sure I've got everything backed up in case it goes down for good.

Thanks

MacPro G5 (aluminum), Mac OS X (10.5.7), 2 x 3 GHz Quad Core

Posted on Jul 30, 2009 12:16 AM

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504 replies

Aug 12, 2013 2:49 PM in response to RGrebrad

I also got SMC fan control, bumped the minimum speed up 50% for all fans, haven't had a restart since, but I also opened the machine, pulled things out and dusted thoroughly at the same time - so I'm not sure which method fixed it. I'm betting that dust build-up can cause a spike in heat that the fans can't keep up with, so it restarts. If it still doesn't restart in a week or so I'll turn off the fan control and see if the problem comes back.

Aug 23, 2013 8:31 AM in response to Jodyberry

I work my macpro hard using 3ds max, After Effects and Premiere and it doesn't restart under heavy load. Sounds like the fan speed is the culprit in some cases, but there must be close to a dozen proposed solutions on this board. Like a few others posted, mine has it's restarting fits duing the first 30 min or less. Once I realized that I have done like another user posted and resorted to just leaving mine on non-stop and it hasn't restarted in around 2 months so far. I'm making a list and as soon as my workload allows me to shut it down, I'm going through all the proposed solutions on this board in hopes of solving it.

I checked and I didn't see a kernal panic report in MacOS even though it restarted in MacOS also.

Aug 23, 2013 10:50 AM in response to Firehawk911

Firehawk911: you hit the nail on the head. There are a number of potential solutions and tried every one of them with the exception of replacing the logic board. I replaced the power supply, obsessively monitored the fan speed with SMCfancontrol, replaced memory, gave the interior a thorough cleaning, even replaced hard drives—all to no effect. My 8-core machine still restarted whenever the mood struck it. At that point, I just gave up and bought a brand new 12-core machine, which is an absolute beast. I will, however, be giving the 8-core machine to a cousin of mine to see if there's anything he can do with it. I told him, if he can bring it back to life on a consistent basis, then the machine is his. I hope he can.


Michael

Sep 4, 2013 1:11 PM in response to jrbuuck

I finally found a solution for my problem - my MacBookPro started having these (not so) random restarts about once every few days and several times on some days immediately after I (IT department of my company) installed new 2x8 GB rams.


Upon lots of research and debugging I found that the new RAM the IT guys installed in my Mac are 1600 Mhz and are not actually compatible with my MBP. My MBP is compatible with 1333 Mhz RAMs and after replacing with a new set of 1333 Mhz 8GB RAMs, I don't have these re-start issues.


Hope this helps someone. It would be great is one could tag the appropriate posts as "solution posts" and move them right next to the question(first post on the thread) since there seem to be quite a few solutions.

Sep 11, 2013 8:06 PM in response to jrbuuck

My restarts happened after I had my screen replaced by Apple. First time I got it back, the machine would crash every time I started After Effects. So I brought it back and they replaced the screen a second time. Now everything seems normal, until a sudden random restart. And when it first comes back, the resolution is wacky, as if it were starting back up in 640x480. Then it goes back to normal.


So I think there's a video component involved with at least some of these issues people are having.

Sep 12, 2013 5:58 PM in response to Mel Gurney

Well for me it looks like it was nothing but dust build-up. I turned off SMC fan control about 2wks ago and still no restarts. So it was either the dust or maybe just a bad connection that got better when I opened it up and dusted it.


Judging from other posts, it looks like the restarts could be caused by just about anything.

Sep 21, 2013 7:29 PM in response to jrbuuck

I had this problem of random restarts within the first few minutes of waking or starting up the Mac Pro come up recently. I removed the USB cable for an Epson scanner and also reset energy saver preferences. Since then no more restarts. Not sure which solved it but it's worth trying the energy saver reset. Also eliminate any external devices to isolate the problem.

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My Mac Pro spontaneously restarts

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