Mac Pro 2013 won't render in the Winter - condensation problems!!

flyingfoxuk

macrumors regular
Original poster
Jan 23, 2015
102
2
Just had to box my 2013 Mac Pro up to return it for diagnostic tests for the second time since New Year - first time was two weeks ago - one morning the computer wouldn't turn on.

Tried all the usual things, fuses, pmc, power cord - no joy. Boxed it up and returned it to my supplier who I bought it from in May last year - it reached them a few days later powered up normally and passed all diagnostic tests, so they sent it back to me.

I work a lot in 3D modelling and rendering in Maxon Cinema 4D - this machine is my daily workhorse

Once it arrived I powered it up and it all worked fine, I got back to doing a bit of modelling in Cinema 4D and slowly started it doing renders again until Wedneday morning this week when it wouldn't turn on again!!

Now I'd had some time to think about this and realised when I'd returned it to the supplier for service I'd boxed it up with some silica gel. So I popped the computer into it's original box with several large sachets of silica gel, and after 6 hours drying time the computer was back up and running - it seems that condensation must be forming inside the mac pro!!

I powered the computer up again Thursday morning and decided to set it rendering a couple of shots for my current project - it rendered through the day fine, all the way through the night until just after 10:00am this morning when it spontaneously shut down and refused to power on again! Very disturbing when you walk into the room and this happens

The computer is now boxed and awaiting a courier return to the supplier again for further testing.

The operating temperature specs for the computer specify a minimum temperature of 10C - I checked the room temperature this morning, 15C so well within operational boundaries.

The 2013 Mac Pro has always seemed to run a bit warm when performing intensive rendering, but it seems a bit ridiculous that I can't use it in this way during the winter months!! It hasn't even been particularly cold this year!

I've used Mac Pro's, G5's G4's for years in exactly the same way as this machine and never encountered such an issue - I really hope it's just me.

Has anyone else come across a similar problem or have just been unlucky with this machine?
 

flyingfoxuk

macrumors regular
Original poster
Jan 23, 2015
102
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House is heated regularly throughout the day, but I don't know anyone who can afford to run it 24/7 - besides the computer is spec'd to run at this ambient temperature so it's not really the point - it's not dripping with water at all, but shutting it up with silica gel to extract moisture solves the problem so it must be condensation of some form
 

netkas

macrumors 65816
Oct 2, 2007
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Correct me if I'm wrong:
Isn't condensation happens only on things that colder than enviroment. not on things that warmer than enviroment.
 

flyingfoxuk

macrumors regular
Original poster
Jan 23, 2015
102
2
So far it appears that condensation must have been forming when the computer is shut down on an evening when after rendering the surrounding air is warm and something within the computer is cooling faster than the surrounding air temperature hence condensation must be forming somewhere - all I know for sure is that twice boxing the computer up with silica gel (which extracts moisture) cured the problem when nothing else would - however that really isn't a viable option and considering today the computer spontaneously shut down whilst rendering there's clearly something going quite badly wrong here
 

netkas

macrumors 65816
Oct 2, 2007
1,122
292
>something within the computer is cooling faster than the surrounding air

Can't happen, to get colder (if computer is not refrigerator, and it's not), you need something that has lower temp than you. if surrounding air is same temp/hotter, you can't get colder.

Well, maybe you have high humidity and condensation happens on macpro's cooler in first moments after you turn it on (hot air, cold cooler), still unlikelly to damage anything. this will evaporate pretty quick.

if condensation has already done damage to computer then silica gel unlikely to help that too.
 

Arran

macrumors 601
Mar 7, 2008
4,353
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Atlanta, USA
It sounds more like overheating to me. Especially if it happens well into a long rendering session.

Probably a bad heatsink or fan? Or possibly a socket or connector working loose after repeated expansion and contraction (caused by shutting the thing off every night).
 

chrfr

macrumors G3
Jul 11, 2009
8,201
2,529
something within the computer is cooling faster than the surrounding air temperature
As mentioned above, this is physically impossible. Condensation will not typically form in the conditions you describe, and it's unlikely that it's the cause of your problem. If there was condensation, you would find it on the outer case. Winter air is typically very dry which means that even at 10C your house is very likely far warmer than the dewpoint.
I have a stereo receiver at home that will not output to one or both of the channels in the morning just after I've turned the heat up until it either gets warmer or if I cycle it on and off a few times. There's a sticky component somewhere in the receiver which is faulty and causes this. The problem is likely due to a faulty component in the power supply in your case.

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Correct me if I'm wrong:
Isn't condensation happens only on things that colder than enviroment. not on things that warmer than enviroment.
Condensation forms when something is cooler than the dewpoint.
 

flyingfoxuk

macrumors regular
Original poster
Jan 23, 2015
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Thanks Arran, hopefully it is something like that and the supplier can sort it out - thankfully the computer is still under warranty, but having run Macs for rendering for over 12 years I've never encountered a problem like this (they have all been run in this same environment!!) I didn't mention before but I do actually run several de-humidifiers within the house as well, one right next door to the computer - so unusual humidity shouldn't be an issue.

With previous machines I've rendered 3D animation with frame times of over an hour for days and weeks at a time without any issue - this machine hasn't really had any hard rendering yet since I've only just moved out of a very long pre-production phase.
 

flyingfoxuk

macrumors regular
Original poster
Jan 23, 2015
102
2
I'm open to alternative suggestions of why this computer is malfunctioning, however my expectation is that operating a computer within it's specified temperature range should not produce these kinds of issues.

Obviously internal heat generation plays a role in the problem because it appears only to happen in conjunction with CPU rendering, which whilst it is intensive should be well within the scope of this machine.

I can only deduce that some form of moisture plays a role since the only remedy I have found is effectively drying it out with silica gel in a sealed box which so far has remedied the problem on 2 separate occasions. With previous mac's if anything I have experienced far more problems rendering during the summer months where higher ambient temperatures cause the fans and cooling systems to have to work harder.

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Why not just leave it on all the time? It'll stay warm and not have a chance to cool down...
That's what I had done for the last couple of days and today it spontaneously shut down and refused to boot again. Often with previous computers I have rendered 24/7 for 6+ months almost continuous on large animation projects
 

chrfr

macrumors G3
Jul 11, 2009
8,201
2,529
Obviously internal heat generation plays a role in the problem because it appears only to happen in conjunction with CPU rendering, which whilst it is intensive should be well within the scope of this machine.

I can only deduce that some form of moisture plays a role
Again, in conditions you describe, condensation is not a possibility. Contraction and expansion due to cooling and warming respectively is by far the most likely cause. When something is nearly, but not quite, perfectly soldered, this is the sort of behavior you will see. The connection will go in and out of tolerance due to the gap getting larger or smaller with temperature changes.
There's no doubt the computer is faulty, but it can be difficult to troubleshoot problems like this because you only get one chance per several hours to get the device cold again.
 

flyingfoxuk

macrumors regular
Original poster
Jan 23, 2015
102
2
Again, in conditions you describe, condensation is not a possibility. Contraction and expansion due to cooling and warming respectively is by far the most likely cause. When something is nearly, but not quite, perfectly soldered, this is the sort of behavior you will see. The connection will go in and out of tolerance due to the gap getting larger or smaller with temperature changes.
There's no doubt the computer is faulty, but it can be difficult to troubleshoot problems like this because you only get one chance per several hours to get the device cold again.
That's why I've thrown the whole mess back to the service engineers - I don't really enjoy playing computer detective - I'm the kind of user who wants it to do it's job, do it properly and not get in my way - not having much luck with that at the minute

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The silica gel remedy doesn't sound like a "remedy" at all if the problem reoccurs.
It isn't a remedy to keep working but it seemingly does allow the computer to be booted and retrieve files that were otherwise inaccessible (needless to say my back-up routine has been somewhat obsessive these last couple of weeks)
 

flyingfoxuk

macrumors regular
Original poster
Jan 23, 2015
102
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Incidentally I am also running an iMac and 3 Mac Book Pro's in the same environment on a daily basis without issue
 

crjackson2134

macrumors 601
Mar 6, 2013
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Charlotte, NC
Could it be that packing with a desicant has nothing to do with it, but that leaving unplugged for several hours does (as in SMC Reset)?

Also, if it just spontaneously turned off while in use, it would seem impossible for condensation to form while the fan is active. I think you have something more going on other than ambient moisture.
 

flyingfoxuk

macrumors regular
Original poster
Jan 23, 2015
102
2
Could it be that packing with a desicant has nothing to do with it, but that leaving unplugged for several hours does (as in SMC Reset)?

Also, if it just spontaneously turned off while in use, it would seem impossible for condensation to form while the fan is active. I think you have something more going on other than ambient moisture.
I left it unplugged for several hours and it did nothing - boxing it with silica brought it back to life - I don't pretend to understand exactly what's happening - I'm just hoping the service engineers can come up with a reasonable answer and a fix - not got much work done in the last 2 weeks!
 

crjackson2134

macrumors 601
Mar 6, 2013
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Charlotte, NC
I left it unplugged for several hours and it did nothing - boxing it with silica brought it back to life - I don't pretend to understand exactly what's happening - I'm just hoping the service engineers can come up with a reasonable answer and a fix - not got much work done in the last 2 weeks!
Bummer to have spent that much and have reliability issues. Hopefully sending back the second time will be the charm. If they can't find the problem, you should get a replacement I would think.
 

chrfr

macrumors G3
Jul 11, 2009
8,201
2,529
I left it unplugged for several hours and it did nothing - boxing it with silica brought it back to life - I don't pretend to understand exactly what's happening - I'm just hoping the service engineers can come up with a reasonable answer and a fix - not got much work done in the last 2 weeks!
More likely, the moving it around would have done it if it's a bad solder. Again, if you can't see condensation on the computer, there isn't enough moisture in the air to be the actual issue. These computers are rated to operate in up to 95% humidity as long as it's not condensing.
 

pertusis1

macrumors 6502
Jul 25, 2010
392
88
Texas
Classic logical fallacy.

Post hoc ergo propter hoc.

;) Hope the engineers get it sorted out. I agree with the idea that it is more likely a faulty heat sink, solder, power supply or something like that.
 

flyingfoxuk

macrumors regular
Original poster
Jan 23, 2015
102
2
Classic logical fallacy.

Post hoc ergo propter hoc.

;) Hope the engineers get it sorted out. I agree with the idea that it is more likely a faulty heat sink, solder, power supply or something like that.
Well whatever it is I'll be glad to have it sorted - I've had to boot up my old style Mac Pro to try and get s bit of work done, but can't really make progress without my main system