haha yeah I'm hoping it's something easy like that and not a bad piece of hardware.
Both data and power SATA cables are connected yeah, both are definitely getting power and both are registering in the BIOS too.
I'll try resetting the RAM.
Could it be the motherboard battery?
You wouldn't get to BIOS if it were the battery. Describe exactly what's going on for me. In my situation, if I prioritize the boot order, my rig POSTs, then flashes an action screen where it prompts me to hit any key to boot from a disk. Do you get that?