Mac mini dual monitor overheat problem

dong_suzuki

macrumors newbie
Original poster
Sep 10, 2016
5
3
Hello:

Is it just me or anyone else whose Mac mini has the overheat problem when connected to two monitors. The overheat problem occurs after two hours' use and the mac reboots itself. When I disconnect one monitor, the problem is gone. So I am 100% sure it was the dual monitor that causes the problem.

I am not a heavy user of computers. I don't do gaming or anything. I just use dual monitor for website viewing and sometimes do photo editing.

Here is the specs:

Mac mini late 2012 version, i5 core, Ram 4Gb, 500 HDD with an extra 128 SSD I installed by myself.
The two monitors are older version of Apple cinema display 23" and 20"

I use two adapters: DVI to Thuntherbold and DVI to HDMI for the monitors.

I suppose the dual monitors drain the graphic card and cause the reboot. Is there any solution to this?

If I get a Apple TV for my second monitor, would that solve the problem?

Thank you very much in advance!
 

jpietrzak8

macrumors 65816
Feb 16, 2010
1,053
6,100
Dayton, Ohio
Is it just me or anyone else whose Mac mini has the overheat problem when connected to two monitors.
I have never had this problem, on a Mac or on any other computer. :) Never heard of it before either. I'm guessing that something more subtle is to blame here...

The overheat problem occurs after two hours' use and the mac reboots itself. When I disconnect one monitor, the problem is gone.
Let me throw out a few ideas:

1) Have you tried each monitor by itself, to rule out either of them causing the problem individually?

2) Have you tried swapping the adapters when using a single monitor, to rule out a flaw in one of the adapters?

3) With both monitors plugged in, perhaps you could check the Activity Monitor -- this should tell you if the CPU is in heavy use, and if so, by what process. It could be that some process notices that two monitors are plugged in and is trying to be "helpful" in some manner.

4) Unlikely, but I'll throw it out there anyway: is it possible that the Mini and the monitors are packed together in a small space, such that having all three running might raise the temperature too high?

In any case, there should be no problem running two monitors from a 2012 Mini. :)
 

!!!

macrumors 6502
Aug 5, 2013
465
410
What does "overheat problem" mean? Does it mean the Mac feels hot to the touch? Is it thermal throttling? Does it shut off due to the heat?
 

jbarley

macrumors 68040
Jul 1, 2006
3,897
1,767
Vancouver Island
Is it just me or anyone else whose Mac mini has the overheat problem when connected to two monitors. The overheat problem occurs after two hours'
What are you using to monitor the temperatures, just what part of your computer is "overheating"?

If I get a Apple TV for my second monitor, would that solve the problem?
Impossible to answer this until you figure out exactly what the problem is...
 

dong_suzuki

macrumors newbie
Original poster
Sep 10, 2016
5
3
Thank you for both reply! By overheat, I mean there is a warning screen pops up and then the mac shuts down by itself.

To rules out the possibilities:

1) When either monitor is plugged in, there is no problem.

2) I swapped the adapters, no problems with the adapters.

3) I am testing the Activity Monitor... I will report in this thread.

4) The physical environment is okay. I live in Vancouver, and my room temperature has never been too hot, and there is a open window close to my computer. It is true that both monitors generate a lot of heat, but I cannot feel it unless I touch them, so I suppose the heat radiation may not be the issue, but I will move the mac further away from the monitors, and give it another two hours to see if it solves the problems. This may take some time to diagnose.
 
  • Like
Reactions: jpietrzak8

grcar

Suspended
Sep 28, 2014
292
127
By overheat, I mean there is a warning screen pops up and then the mac shuts down by itself.
As you may know, the all-in-one cpu-graphics chip has sensors to monitor temperature at a few points. When the temperature gets high, the fan should speed up, and when the temperature gets too high, mac os shuts down to protect the machine. You can install some third-party software to read the sensor values.

Anyway, your machine is overheating because either (1) the mini cooling system as designed is inadequate to the task of running two monitors for a long time, or (2) the thermal paste on the heat sink has deteriorated.

Since you have installed an SSD you must have gone so far as to remove the heat sink once already. You can try replacing the thermal paste again. (I assume you put on new paste when you installed the SSD.) Some other readers have reported that the heat sink does not always lie level across the cpu chip, which seems to be a design flaw.
 

dong_suzuki

macrumors newbie
Original poster
Sep 10, 2016
5
3
As you may know, the all-in-one cpu-graphics chip has sensors to monitor temperature at a few points. When the temperature gets high, the fan should speed up, and when the temperature gets too high, mac os shuts down to protect the machine. You can install some third-party software to read the sensor values.

Anyway, your machine is overheating because either (1) the mini cooling system as designed is inadequate to the task of running two monitors for a long time, or (2) the thermal paste on the heat sink has deteriorated.

Since you have installed an SSD you must have gone so far as to remove the heat sink once already. You can try replacing the thermal paste again. (I assume you put on new paste when you installed the SSD.) Some other readers have reported that the heat sink does not always lie level across the cpu chip, which seems to be a design flaw.
I do not need to remove the heat sink to install the SSD in this model. There is just a nice little empty space and no need to take anything off the motherboard. The installation was done a while back and nothing unusual. The cooling system seems to work well when there is only one monitor. Give me a few more time to test the dual monitor.
 

jbarley

macrumors 68040
Jul 1, 2006
3,897
1,767
Vancouver Island
Since you have installed an SSD you must have gone so far as to remove the heat sink once already.
That's news to me, I've installed SSD's in 2 mac minis and have yet to remove the heatsink from the CPU.

What could have easily happened is the fan sensor or power wiring could have got damaged or left unconnected during the SSD upgrade.
 
  • Like
Reactions: jpietrzak8

dong_suzuki

macrumors newbie
Original poster
Sep 10, 2016
5
3
3) With both monitors plugged in, perhaps you could check the Activity Monitor -- this should tell you if the CPU is in heavy use, and if so, by what process. It could be that some process notices that two monitors are plugged in and is trying to be "helpful" in some manner.
The CPU seems to be running normal when both mons are plugged in. I took a screen shot in here.
 

Attachments

  • Like
Reactions: jpietrzak8

grcar

Suspended
Sep 28, 2014
292
127
The CPU seems to be running normal when both mons are plugged in. I took a screen shot in here.
Yeah, but the cpu is not the graphics system. You need a app that reports temperature at different spots on the chip.

You are correct and I was wrong about the heat sink removal.
 
Last edited:

jpietrzak8

macrumors 65816
Feb 16, 2010
1,053
6,100
Dayton, Ohio
The CPU seems to be running normal when both mons are plugged in. I took a screen shot in here.
Cool, so we can rule out a runaway CPU process. So this really is either a GPU problem, or some other issue involving the cooling system.

But I like jbarley's idea! This:

What could have easily happened is the fan sensor or power wiring could have got damaged or left unconnected during the SSD upgrade.
So, the next question is: as the overheating approaches (near the 2 hour mark), can you hear the Mini's fan speeding up in its attempt to keep the machine cool? Or does it remain silent? If the fan is not working correctly, then even normal levels of use could cause the Mini to overheat...

EDIT: Also, even if the fan is running, it won't work correctly if the air passages through the machine are blocked. I'm not sure exactly how air circulates through the 2012 Mini, but that might be another issue to consider.
 

elolaugesen

macrumors regular
Aug 1, 2008
107
3
Hi: I run two monitors and do not have a problem with overheating, but I had a problem at one time and fixed it..
I also installed a ssd myself and it ran just fine. then I added a second monitor and I found I started to overheat a little bit. solution...

check to see if you replaced the fan connection properly when you installed the SSD. I opened up the machine pushed down on the fan connection and problem was solved..

cheers elo
 

dong_suzuki

macrumors newbie
Original poster
Sep 10, 2016
5
3
Hi guy. Just a report to all who has helped me in this thread and those who may have the same concern. In the past weeks, I have been monitoring my dual monitor and the reboot has not occurred. I noticed that the Mac mini heats up more with 2 monitors than 1. I do not have an app to read the temperature, but my hands feel the difference. That said, the Mac can tolerate it. I think, compared to the problem in the past, it is that I place the Mac mini further away from the monitors and the power adapters to avoid the heat, which makes the difference. Another possible contributor is that I have not been using video editing software that much, which is demanding on the graphic card. That is just my observations.

Just to add one more thing. If no one else has the same problem, I suppose maybe some part of my mac is not working well 100%. I dropped the mac mini to the floor more than two years ago and the Apple store fixed it with the replacement of a fan. Nothing else is broken they told me, and I have never experienced a problem with it until I have the dual monitors a few month back. Now I am happy, and it seems to be okay and i hope it will last.
 
  • Like
Reactions: jpietrzak8

Julien

macrumors G4
Jun 30, 2007
11,279
4,257
Atlanta
Not mening to highjack the thread but have a similar question. Just got a Late 12 and I have 2 Display Port (2560x1440) monitors. Can I drive both of these (Extended mode) from the Thunderbolt port and if so what adaptor do I need?
 

stenrw

macrumors newbie
Dec 18, 2019
1
0
Hello,

I have the same problem where after approximately two hours the my thunderbolt to hdmi adapter output shuts down. If I unplug it and plug it back in the monitor will work for a short while. However, the level of heat in the mini correlates with the run time of the 2nd monitor. The hotter the mini the shorter the run time. I have read all the above and addressed all proposed resolutions. Any other ideas???
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.