Well to be blunt, Memory issue like rexharbinger
wrote about is the correct his diagnosis there is better explained than i could ever hope to explain,
if it was the graphic card, you would experience either problems with doing anything like graphic glitches.
Or an insta shut down the moment you put on a high use program/game. Because it sounds like it is not overheating,
and you haven't seen glitches like i described because thats a clear sign of graphic card issue.
I am willing to bet it is the ram memory, now what type of ram problem that is the the problem i will list 3 main problem
that is possible without overheating ram or video card.
1 as rexharbinger said a Defective RAM memory. or in other words damaged beyond use you need a new one.
I doubt its too little ram memory honestly, but a clean up on disk and such could also be helpful.
2 the ram memory doesn connect to the system could be cause of lots of stuff, virus/malware that is blocking space from being used, or even system file/files missing because of a virus/malware that is now gone.
3 Lose ram memory holder or the part were the ram memory is sitting is not fully connected >|< the | is space.
The last part is just a pure guess that if not the ram in some how someway then id say it must be the SSD disk (i do assume he has that) is if that one is damaged somehow it can become troublesome, HD disk are actually able to take more damage both internal and external just because its wired in a different way, but SSD disk are high end tech sure but one that still is less reliable when it come's to taking blunt damage or virus/malware blocks is us.
If the power button is being a pain, well how old is the computer?..
