Okay so the problem is most likely motherboard-related, but it could still possibly be the RAM or PSU. The CPU, GPU, storage drives, and peripherals are all totally fine. Probably.
computer shit itself overnight it seems. Woke up to it seemingly powering on fine but no connection to the monitor and I don't have anything else with a DP or HDMI port to test with to see if it's a monitor, cable, or computer issue :/