Computer stopped working- any advice?

Oh, sorry- posting/reading from my phone.
I was hoping you guys could help me out- I think my computer just died. I was watching Netflix, stepped out of the room, came back and it was frozen. Keyboard wouldn't do anything, turned it off with the power button. Now when I try to turn it on, everything (fans,lights, disc drive makes a noise) comes on for about a second and then shuts off, waits a second or two, then comes back on for a second, shuts off, repeat... Any ideas?