Power supply is there but cpu not starting?

Okay..have a big problem here..today i was jus cleaning my desktop icons and i started skype n was jus abt to msg my friend that suddenly my pc crashed...i tried to start it again but its not happening...my monitor is blinking light i.e. its working fine..the power supply is fine..but my cpu is not starting...no burning smell from the cpu backside..idk wat has happened...please helpe me !! :(