My pc has worked for years. But two days ago it stopped turning on. When I click the power button the fans run for a split second and shut off. I took out the mother board and placed it on cardboard, to check if the case is shorting it out but that didn't work, I took off everything except the ram, CPU and CPU fan. It still just starts up for a split second. I cleared the cmos. I reset the ram and tried one at a time. I also reseated the CPU. I tried a different psu bad the same happens, please help!