Laptop goes to shutdown screen abruptly

[vlladonx]

Hi, I'm new to this site, as to any forums in general, but I was wondering if someone would help me identify what's wrong with my laptop.
It's been used for at least two good years and 've been working better or worse, I'm currently running W8, I've cleaned it many times and it isn't overheating (as far as I can tell by checking the fan.
The problem is that after an hour or so of use, it just goes to the Shutting down... screen. Sometimes it shuts down during a game, sometimes during a video or if I wait long enough it'll shut down on the desktop without any apps running.
It's really frustrating and weird, there are no errors or any indications as to why it shuts down. Happened about 20 times for the past few days. Ideas?

 

[Tmagic650]

The laptops thermal compound has probably gone bad and hardened... This causes the motherboard to trigger its "overheating" circuit, even though it doesn't seem that hot

 

[tipstir]

Could be that the system is overheating. Is the internal fan that cools your laptop spinning. Force some air from a dust removal can to clean out the vents. Get yourself a multi-AC/DC tester and test the voltage amp on the power supply cord t make sure it's running at peak numbers. It it not then that time needs to be replace. Also check the battery terminal also see if the battery is running and charging correctly. Need to rule out things.