My PC shuts down suddenly after 2 or 3 minutes of use

[Tachyon876]

My PC shuts down suddenly after 2 or 3 minutes of use, when I try to power it on immediately again, the power light turns on and the screen gets lit and the fans spins but it shuts down immediately. when I put the system down for a while or turn it on the next day, I am able to power it on again and use it but then it shuts down after a few seconds to a minute or 2 and does the same thing  (after it boots  no error messages come up)

Note: I went to someone's (air conditioned) office to change the hinges for the system, I was able to boot and use the system for awhile without it shutting off. I was able to turn it on and off as freely as I want and use it as much as I want...I came home, turned it on and was able to use it until I had to leave the house again, came back, turn it on then the same problem with it shutting off after awhile came back as well.

Personally I am wondering if there could be an overheating problem. I have changed the fan and the fan works but I haven't changed the thermal paste since i got it pc

[RickMtl]

before doing anything major, try another A/C adapter charger.  When a laptop powers down automatically, it if often an almost dead battery.  It is a simple a quick test.