EDIT: your system specs are the one on your profile yes?
troubleshooter:
-open up your pc, disconnect the power chord from the wall outlet.
-look inside and see if theres any physical signs of damage: poped/leaky capacitors, scorch/burn marks, scratches, excessive dust and debrie etc.. and also use your nose to smell if anything has burnt out
-inspect your motherboard is not shorting out on the pc case (all screws are correctly placed etc)
-do you get any fans running/devices running?
-disconnect/uninstall all extra devices and go to basic [mobo,vga,sound,cpu,psu] and try to boot.
-reset your bios by either jumping the cmos clear pins or taking out the cmos battery
-reset your psu by unpluging it from the wall outlet and holding the power button for 15sec, conferm the voltage setting is to your country standards (240v/120v)
-have you had any power outages or spikes recently?