laptop almost melted, what happened?

[Ernest Burden III]

I have been working with computers since the 80's, so by now have seen just about everything. But I had a scary new issue yesterday and I'm not sure what happened.

 

I have a very good, expensive and well-made laptop. It often runs at 100% CPU for days on end rendering stuff. It can get quite warm, but never overheats.

 

Yesterday I was about to go somewhere and shut down. But first Microsoft pushed a bunch of updates (Win7) which installed, then finally the screen said 'shutting down'. But it never quite did. I wanted to go, so I closed the top, put the machine in my backpack and figured it would 'sleep' and I would deal with forcing the restart when I got where I was going. But an hour or so later, when I got my backpack out of the car, the laptop was hot, so hot I risked burning my hands picking it up and getting it onto a table. I opened the top, held the power button and it seemed to go off. Much later, it cooled and restarted and seems to be OK so far.

 

The heat was not from the battery, it was the entire bottom so the mainboard.

 

How could a failed shutdown put the machine into such a state that it would heat until it failed or caught fire? Pretty scary, both the risk of it setting my car on fire as I drove and of losing a very important part of how I work.

 

What happened?

[Scott Schroeder]

Perhaps during the shutdown and lid closing you somehow tricked the CPU to turn off cooling, but the CPU itself never shut off. I'd imagine that even at idle a CPU can generate a good amount of heat if left uncooled, especially if the laptop was in an air restricted bag.

[RyderSK]

I think you wouldn't be first, by running full throttle closed you loose significant part of passive cooling. But I don't think it would burst into fire :- ) Just melted some connections and shutdown.

[Ernest Burden III]

Well laptops do sometime go all flambe, but that is usually the LithiumIon battery. Speaking of which, I had a fully charged 100W supply of juice to be fed into the board. I'll be lucky if I didn't melt off any of those tiny solder points.

 

Maybe the OS didn't get put to 'sleep' because it was hung trying to shut off. I should have forced the powerdown before leaving, was just concerned since the updates were being added, didn't want to brick the laptop. Instead, I brick ovened it.

 

Thanks!

[Ernest Burden III]

Googled that, found out that Win forced updates have led to many computers not fully shutting down/re-booting. Great. Just about melted a $4000 laptop, but at least I know my OS is up-to-date.

 

Thanks Obama!