My comp switches off after a few seconds of switching power on everytime, i have stripped it down to just mother board and processor with fan. any ideas

Any beeps?

Mobo + CPU + RAM?

Is this a new board? If not were there previous issues?

Are you sure that the CPU & RAM are compatible?

What is the make & model of the mobo?

No i getting no beeps,
gigabyte mother board
was running great untill the other day when switched on after adding a new usb card, then my hard drive popped and one of the chips on it went up in a flame, i put new hard drive in and tryed changing power supply but still the same,
what i tred today was took processor off board and it stayed powered up, put cpu back on and shut down again a few secs after power on

Perhaps someone else will have an idea but as "one of the chips on it went up in a flame"