Heat sink working.But laptop shutdown

[itsmehisham]

Hello.. I am using Dell N5110. My laptop is turning off automatically due to overheating.The fan runs very fast and i can feel the hot air coming out. I tried cleaning the heatsink. But i didn't put any thermal paste after cleaning. Now the problem increased.The laptop isn't that hot too. Still it shuts. Can it be the problem of any temperature controller or Something?

 

[jsmithepa]

But i didn't put any thermal paste after cleaning

That is not acceptable for a normal functioning CPU. At his point I even doubt if you cleaned it properly.