My pc sometimes powers on and sometimes doesn't power on. The lights on the case always turn on. The peripherals have lights that turn on when it boots, but not when it doesn't, so it isn't a display problem. It does not show a screen that says anything about the boot drive. I have replaced the psu and reseated the ram and cpu. I changed the ram slots. Just in case I even checked the drive cables. Just in case it somehow was graphics I also used the boards vgi while the gpu was out of the case. When it does turn on all of the settings stay the same so it isn't the cmos. I can't think of anything it could be but the motherboard. I just wanted a second opinion.