Scary incident - Macbook Pro spun up in bag

eladnova

macrumors regular
Original poster
Aug 31, 2012
115
9
Hi all

I was working in the home office yesterday and realised the laboured fans I could hear were actually coming from a closed laptop bag and my MBP (2017) inside it.

I immediately took it out and to say it was hot is an understatement. The bag was also over heated.

Obviously the Mac which had been sleeping had come on at some stage and the fans were at full throttle in an attempt to cool it within a very cramped and padded laptop bag.

Approx 15 mins after the incident, I inspected the CPU temp and had a reading of 70+ degrees

What worries me about this incident is that
  1. The MBP can come out of sleep while packed
  2. I was travelling that day with the Macbook and while stowed away, the MBP could have caused a fire in transport
  3. This has happened before once
I am now turning my MBP off before I travel or even walk home from work.

There are two things to note about my setup
  1. I boot and run from an external SSD which is permanently plugged in
  2. In my System Prefs > Energy Saver, I had checked "Prevent computer from sleeping automatically when the display is off"
I'm hoping that the culprit was number 2 above.

Has anyone else had this issue and what did you do to resolve?
Thanks
 

The Mercurian

macrumors 68000
Mar 17, 2012
1,823
2,054
This happened my 2014 MBP once in the 4 years I have had it. The battery was drained when I found it and the machine was roasting hot. No clue why it happened, and it didn't happen again. :oops:o_O Kind of scary thing to happen honestly, but since it only happened the once I stopped worrying about it - I still had it at least a year after that with no recurrence.
 

leman

macrumors G3
Oct 14, 2008
9,963
4,550
  1. I boot and run from an external SSD which is permanently plugged in
  2. In my System Prefs > Energy Saver, I had checked "Prevent computer from sleeping automatically when the display is off"
I am sure thats the source of your problem. Sleeping can be unreliable if you are booted from an external drive. If thats how you want to use your machine, shutting it off sounds like a plan.
 
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Thysanoptera

macrumors 6502a
Jun 12, 2018
722
723
Pittsburgh, PA
Check the logs, this will tell you what caused it to wake up. I had mine running in a bag during three hours drive, whole bunch of Bluetooth events in logs - left my BT mouse on.
 
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Howard2k

macrumors 68030
Mar 10, 2016
2,556
1,821
I routinely kept mine in sleep mode when using Sierra and never had an issue, but since High Sierra sleep is useless. Even worse in Mojave.

With regards to the temperature, won't the MacBook shutdown if the temperature is too hot? I know it would have been too hot for us mere humans to handle, but the MacBook tolerance is higher obviously. Notwithstanding the potential keyboard membrane issues on the new ones, is there a real risk of damage from heat in this scenario?
 

Atreyu25

macrumors 6502
May 31, 2005
287
147
Hi all

I was working in the home office yesterday and realised the laboured fans I could hear were actually coming from a closed laptop bag and my MBP (2017) inside it.

I immediately took it out and to say it was hot is an understatement. The bag was also over heated.

Obviously the Mac which had been sleeping had come on at some stage and the fans were at full throttle in an attempt to cool it within a very cramped and padded laptop bag.

Approx 15 mins after the incident, I inspected the CPU temp and had a reading of 70+ degrees

What worries me about this incident is that
  1. The MBP can come out of sleep while packed
  2. I was travelling that day with the Macbook and while stowed away, the MBP could have caused a fire in transport
  3. This has happened before once
I am now turning my MBP off before I travel or even walk home from work.

There are two things to note about my setup
  1. I boot and run from an external SSD which is permanently plugged in
  2. In my System Prefs > Energy Saver, I had checked "Prevent computer from sleeping automatically when the display is off"
I'm hoping that the culprit was number 2 above.

Has anyone else had this issue and what did you do to resolve?
Thanks
Ugh my 2016 15" did that once, same situation. I ALWAYS shut down now before bagging it.
 

Honza1

macrumors 6502
Nov 30, 2013
413
137
US
Hi all
There are two things to note about my setup
  1. I boot and run from an external SSD which is permanently plugged in
  2. In my System Prefs > Energy Saver, I had checked "Prevent computer from sleeping automatically when the display is off"
Has anyone else had this issue and what did you do to resolve?
Thanks
For many (over 10) years I carry my MBPs (currently MBP2017 on High Sierra) always sleeping, basically I never shut down, only reboot once in a while.
I had what you describe happen once, few years ago and at that time I believe I put computer in the bag BEFORE the fans cooled it down and BEFORE (the fans) powered off. It can take on my current MBP a minute or even more to cool down and power off the fans - depends on how hot it is. The fans are configured to continue cooling until system is cold enough, even when a sleep. Only when cold enough, the fans power down. If they cannot cool the system enough (due to being in the bag), they'll just keep going, effectively warming the system more and more...
Now, if your system wakes up (e.g., "Enable power nap while on battery power") and is hot, fans will start cooling. Again, if in bag, they can overheat the system and eventually drain the battery. I do not think there is chance this would cause fire - except if the battery would explode due to overheating. In any case, it is bad thing to do!
My solution now is to put computer to sleep (close screen) and WAIT until fans power down. Just listen until it is quiet. Then put in bag. I try to keep the bag in colder places (like, not in hot car or on top of heating system) and this never happened to me again.
Also, I have "Enable power nap while on battery power" OFF. I suspect other things could wake the notebook also, you may need to figure out who wakes it if that is your case.
 

Fishrrman

macrumors P6
Feb 20, 2009
17,179
5,533
OP asked:
"Has anyone else had this issue and what did you do to resolve?"

If you don't want this to happen, the solution is simple:
SHUT IT DOWN (power off) before you pack it into your travelin' bag.
 
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IdentityCrisis

Suspended
Sep 9, 2018
685
340
I've had a laptop do that to me, years ago, and now whenever I take the laptop with me, I shut it down.
Yep, same here. My Dell XPS for work does this all the time. I close the display, and wakes up in my bag and is hot. I have to shut it down to prevent it.
 

Premal212

macrumors regular
Jan 26, 2017
175
67
London UK
.... WAIT until fans power down. Just listen until it is quiet. .......
This is it, I've had this a few times, just because you shut the lid does not mean programmes may force the machine to remain on. I've tried updating my OS with the lid shut on the tube once, and another time my bluetooth mouse kept my machine on whilst travelling.

Providing there isn't anything to keep the mac running, it will be fine, but just make sure before you slam the lid shut !