My Mac Pro spontaneously restarts

Thanks for the update.

I'm sorry to hear about your fried logic board. I took my Mac Pro (early 2008) model into an authorized Apple repair shop a few days ago. I called them this afternoon and they said that so far, the computer seems to be running fine but that they want to work on it over the weekend and put it through some more paces.

I hope I don't have a logic board problem... but if that's what it ultimately comes to, does anyone know how much a repair would cost (ballpark figure)? Not that there's ever a good time to spend money unnecessarily, but for me, right now, REALLY isn't a good time.

Ugh.

I too have the same problem re mac restarts the repair shop said it was running fine although they did not log in .I had taken it in since it had gone beyond the restarts to not starting at all. I am now awaiting results from them I originally bought the mac pro under the impression that it would be robust but these last few months I have felt that I have been nursing an unwell beast . I have regally run disk utilities ,dusted out the interior put extra fans on the outside during the summer and have monitored it with i-stat pro . I had a hard disk failure on the operating disk and replaced that and I have four hard disks installed one for the operating system ,one for photographs,one for iTunes and the last one is partitioned with windows seven and the other bigger partition has other files and films on it . The other problem I have had is with the DVD writers both seem to be prone to dust and they have to be dusted and the lenses cleaned before use, fortunately this is rare since I do not like this sort of media .
So like you I wait to hear what the problem is I did once have problem with an airport express which before binning it I opened it up to discover that all the problem was was a snap on connection which had worked loose so let's hope that perhaps the fault is something as simple as this rather than the actual hardware, if not let's hope that apple starts taking an interest in what surely are their flagship models.

I have had the similar problem over the past month. Early 2008 mac pro. The shut down appears to be random for me. I could be working in Aperture or using Safari and the screen goes dark from top to bottom. Instructs to do a shutdown via the power button. For me though the computer does not restart automatically. I have to do the shut down and restart it myself. Logic would dictate that there has to be a commonality here besides these all being early 2008 Mac Pro unless there is some sort of manufacturing defect with every unit sold during this time frame, and suddenly they are all becoming defective at the same time. This would lead me to believe there needs to be a firmware update coming. Don't think it is software related.
I actually purchased mine from the Apple store as a refurbished model to save a few dollars.
I tried doing the normal things that have already been suggested, smc reset, pram... blah, blah,blah
To no avail. Sorry I can't help the others who posted here, just trying to keep the thread fresh.

@brkfstatiffanys

This actually sound like a different problem than what most of the rest of us are experiencing here. Your problem sounds like what is known as a "kernel panic".

The good news is that this is usually (but not always) related to faulty RAM, which is a lot easier and cheaper to replace than the logic board. You might want to do an Apple Hardware Test and see if the RAM comes up faulty.

I'm not an expert but others can chime in with their opinions.

Your problem sounds slightly different from mine since when my mac started everything was normal and when it shut down randomly there were no warnings . I have experienced shut downs like yours once or twice on various macs and would suggest that if you have not try to verify the operating system disk and if it needs repair follow the instructions which requires restarting from the install disk to repair the disk. I am not sure that this is the problem but it is something easy enough to do just incase this has been overlooked .If it needs a firmware update it will normally do this itself you will see a grey progress bar on a white screen at start up if you get a firmware up date.
Let us hope that answers are on the way for the early 2008 macs but your experience sounds slightly different from mine and perhaps one or two others . That said it seems odd that it would seem that a mounting number of people are experiencing problems with what one would have thought a bullet proof top line machine especially for those using their machines professionally.

Ready to pull my hair out over this....
( and thanks for any help offered in advance )

Long time Mac lover, user & tinkerer.

I have a Mac Pro 8 core 3.0ghz ( A-1186 )
Inten Xeon 5365 CPU's
The build date Aug 7 2006
The motherboard sticker 630-7951
2.1 vers.
Purchased used,last month, has not run correctly yet.
This was going to replace my G5 2.3 dual.

This Mac looks like is was in front of where the owners would dump out their
vacuum cleaner... so I went inside and cleaned EVERYTHING.
and put new Arctic silver on the CPU's.

The machine boots off the hard drive or a boot disc.
I'll get all the way up and can start using the machine for a limited amount
of time.then black screen , boot chime & restart. and the more " load " ( read game or something processor intensive ) causes it to restart faster.

While running looking at the motherboard diagnostic lights
The GPU light goes away.and the EFI GO blinks off.
The machine shuts down & restarts right back up......

Im stripped down to 2GB of memory ( 2 1GB sticks ) in the bottom..
This cycle takes about 7 minutes when the machine is " cranky ".
And it's random... last night I ran for 2 hrs with NO ISSUES...
this am .. back to the 7 minute thing.
On restart..
Trickle on..
Power on..
Then the EFI GD.. goes on & stays on
Then the GPU light comes on..
( the gray Apple screen and the spinning gray " gear " icon )
Get to blue screen
Get to desktop
GPU light blinks~
EFI blinks~
commence restart...

I have tried the following
Measured power supply 4.96 & 12.05
Reseated EVERY connector
Reset the PRAM
SMC reset
PMU reset
New battery
Brand new Apple video card
Tried 2 KNOW working DIMM holder cards & know memory.
Sacrificed a goat & chicken as a last ditch effort.


But then I called Apple support.. ( which confused me more ).
They state the following...
I have the Ram installed incorrectly..
Each of the matched pair should be 1 single stick in the upper 1 single stick in the lower. ( the machine will not boot in this config ).

NOR will it boot with a pair in the top AND bottom cards..
But either card , one at a time in either slot will boot.

Add to this.... if I put KNOWN 800 memory into the slots... it still comes up as 667
The online user's manual states on page 43 that the memory must be 800
But the spec sheet states 667.
ARRGGHH

It will not make it through apple hardware test. ( with either memory ).
And at this point I think I have a memory controller issue
So I guess my motherboard is gone...
We love Mac's states I need a 661-4307-R for a replacement

HELP

Mike

So if I hold the power button while plugging power in.. the Mac goes into hurricane mode.. and NOW I am able to run..

I just did a clean install... that was OK.
Just downloading updates.. going smooth.

So it's obvious something thermal( that isn't monitored ) is happening in my MP.

Mike

So I was able to pass hardware test in Hurricane mode.
I installed a fan program to run the fans up to 1500 rpm.
This allowed me to run, update and do everything like I normally would do.
BUT
I still cannot put known good ram into the bottom pair on the DIMM holder.
So I guess my motherboard is KAPUT...

Mike

I second this observation. In "hurricane" mode my Mac Pro works perfectly. Otherwise, spontaneous and uncontrollable startups ensue. How can we repair it other that replacing logic board for $1,000?

Milan

Thanks Phillip R.
Your suggestion turned out to be true in my case. I finally found the faulty RAM and removed it. Didn't even have to do a hardware test. When I looked in system profiler it showed I had two empty slots were there should have been memory. I shut down and restarted and checked again and they showed up... I quickly experienced a problem, likely the "kernel panic" you referred to. I have not experienced a problem after removing the faulty memory. The only sad part about this is I have to back to 6GB for awhile until I can afford more.

I ordered a new motherboard from We Love Mac's....
I think I'll add a small fan to the northbridge just to be safe..

In this version the heatsink is pretty plain vanilla..
In later models it had a larger radiator fitted to the existing heatsink..

So that IS an apple design...

In short my unit was choked by dust bunnies, got baked, tossed part of the northbridge
( so I couldn't run with dual dimm risers AND put memory in the top AND bottom at the same time )

Mike

Just wanted update my Mac Pro situation. Unfortunately, I don't think it will be too helpful to anyone since... well, nothing out of the ordinary was found.

I took my Mac Pro to an authorized Apple repair service center last week. According to them, they ran a battery of tests but claimed to have found nothing out of the ordinary. I will take them at their word. They did note that one of my internal hard drives (of which I have four) was "on the verge of failing", which was news to me. I don't know if that triggered the problem (nor do they), or if its failing status is a result of the sudden restarts, or if it's just coincidence.

In short, I still think there's a problem, but it might be related to my Apple Cinema Display monitor; apparently, the power brick has been known to cause problems, and perhaps that is creating some interference with my computer.

As you can see, I am just reaching for straws. In the meantime, I will continue to monitor the situation, as well as peruse this thread from time-to-time. If I have to take it in for repairs again, I will do so directly to an Apple Store and see what they have for me.

Good luck to everyone else!

P.S. With respect to a failing hard drive, does anyone know of any software that will help to detect which drives are in danger of failing? I ran Disk Utility and Drive Genius when I was doing my troubleshooting and never found any hard drive problems. Thanks.

Naveen,

I have an old 23" Apple Cinema Display (from early 2004) that I use as my second monitor, with the big power adapter and ADC/DVI adapter. Is this what you have?

Philip R.,

I believe that is the same monitor, but I bought my mine in mid-2006 so I don't know if there was an actual change with the model. To be clear, the bezel around my monitor is hard angled, and not the curved styled monitors that Apple had in the early 2000s.

My one power brick failure occurred back in '07, I believe, but since then (assuming that the monitor's power brick is not the cause of the sudden restarts I have experienced recently), it's been performing normally.

Regarding the computer and the sudden restarts: at the risk of jinxing myself, so far, so good. I've only had the computer back for about two days, but I'm keeping my fingers crossed.

Nevertheless, it still doesn't answer the question as to what is causing the restart issue. I shall update when the need arises...

Add me to the list.

MacPro, 2006 first generation. Random restarts even if the computer is at the logon screen.