CS21S suddenly is powering off

Hello,

I own a Sony Vaio CS21S since more than 2 years ago. The Operating System is Windows 7 professional SP1 64 bit. The problem is that within the last 2-3 months the laptop suddenly powers down without any apparent reason.
The first thing I've thought is the overheating, but this happens even in case I use a notebook cooler (fans + pad) and the room temperature is at 20-22°C.
Generally, it may happen when using many heavy applications together, like photoshop+autocad+artlantis+firefox+skype and after many hours of use. I am aware that the first three application are weighty, but this behavior seems too strange for me.

I've read something about this issue in Internet, but I don't find the web page about that anymore.

Please, can somebody help me to understand what could the problem be?

 

Problem solved putting the oil in the fan pin. The fan is no longer creaking and it is better cooling the cpu now.

 

It does sound like a heat issue - since you're happy to open it up, might be a good idea to reapply the thermal paste and give the innards a good clean to get rid of accumulated dust.