My Laptop shut itself unexpectedly

One bad lead can cause a computer to continue on a cycle or to shutdown or fail to detect your hard drive boot up

test all leads that attach to your hard drive including electrical extensions, SATA

the leads from your ((motherboard to your hard drive)) make sure they have a secure connection and are not faulty or just replace them they could be faulty

make sure all leads that are attached to your drives dvd\cd have secure connections and are not faulty or just replace them they could be faulty ?

make sure the CPU central processing unit has thermal grease and a dust free secure seating

even something as small as an electrical extension or a faulty fan lead can cause this problem computers need all of the data and electrical current to travel through every working device and to have an end for a computer to be able work properly

could be a memory dump you might have to many programs running at one time putting to much stress on the cpu not having enough ram will do this

if you right click in the bottom toolbar select task manager applications you will see whats running also processes you will see whats ticking over if you see something running that should not be select end now you might even uninstall that program and some unnecessary programs

check your computer ram and cmos battery to make sure they are securely seated and the battery has plenty of charge

some motherboards cmos batteries are soldered in

hope it helps