So my computer suddenly stopped working. It would turn on and off repeatedly, and the best advice I could find was to take things out until it stopped. I found that one of the ram sticks was the problem, or so I thought, but I put it back in and it started working again, except the display didn't work. I've tried hooking up a new hdmi cord, trying a different monitor, removing my gpu and using the onboard hdmi port. I'm pretty sure something is broken, but I can't figure out what and i don't really have the spare parts to troubleshoot, is it my motherboard?