My PC is shutting down automatically after some time. i cant figure out the reason behind this.
It refuses to even turn on sometimes.
When i press the power button to switch it on the fan rotates, i hear a beep sound and then the PC shuts down.
Is this something to do with power supply.
as you describe it shutting down then refusing to start im more inclined to think its a temperature issue...
you can test this very easily... if the pc shuts down and you cant reboot it. turn it off at the wall and hit the power on button on the pc. if you have any led's attached they should light up for a split second while the motherboard discharges the residual current...
now hit the power off on the back of the psu if you have 1.after 30 seconds (to be sure) turn on at the wall and on at the psu now the front... now if it boots its likely to be a psu issue. if it doesn't, it could be the temps are still high in the case, and the pc shut down to protect itself... normally points to cpu temps being high. but other temps matter 2 so dont discount them either.