Laptop overheats when in a vertical position.

[techknight11]

So I have a interesting problem that I can't seem to find anywhere else on Google. Whenever I place my laptop in the vertical position the fan starts blowing ice cold air and the CPU temp shoots up and after ~3 min it shuts off b/c it thinks it has overheated. The attached picture shows what is happening on a graph and had I let it go past one min my temp for the CPU would become F190°+. My graphics (which is connected to the same heat sink as the CPU) is never affected. I have taken the laptop apart to see if the heat sink was screwed down correctly and it was. The thermal grease still looks fresh (added a fresh coat about 3 months ago). I'm really lost for what to do now and it seems that when I carry it while not doing any demanding tasks it will only last for less than a minute. This is Really confusing any help is appreciated.

Laptop is a Acer Aspire 5741G

Pic: https://mega.co.nz/#!htkCGYBC!TU4zgMm1IY3-QNBybyNFhNbZJTVm15kiYu8bQABZNfs

 

[Someone Somewhere]

That is interesting.

Note that you should clean the old thermal paste off before applying the new one - but that shouldn't cause this issue.

Weird.

 

[cakans]

Same with my Acer Aspire 5742G.
At the beginning I put my laptop vertically so fresh air could easily get suck in with fan, but after few months I noticed that laptop overheats in that position and shuts off. It`s very interesting, because other laptops does not act like mine.