Obviously, when this happens at startup, it won't come on. It just flashes its lights until I shut the power off. When it happens at shut down, it'll start flashing after the monitor turns off -- about when a healthy, normal PC would be completely off, mine will instead be flashing its lights. When this happens, no fans are spinning.
I've checked all the connections. I've checked that the heatsink is all the way in (it's stock). I've moved my one 8GB RAM stick. I've checked my temps, they're reasonable. When it does work, I don't know why. I just keep trying it, and it eventually works and runs perfectly fine for hours on end.
What could this be? Thanks in advance.
Asrock H97M Anniversary
Intel i3 4170
Crucial Ballistix RAM
Edited to add: Sorry if this isn't the right place, I'm new here.
Edited by Obfkhalp, 14 February 2016 - 01:55 PM.