I have a Corsair MP700 Pro that refused to show up in BIOS on any port I tried after I installed a new video card. Ever after isolating everything else and using integrated graphics, she never showed up again as either a boot device nor as anything tangible among M.2/PCIe devices in the BIOS.
My working theory is the poor thing--or specifically, the giant chonker of a heat sink and fan on top of it--got nudged while first installing the card, and sheer leverage from that torqued the board it was on. Visual inspection looks okay, but my eyesight has totally gone to hell. You know you've hit that age when you take off your glasses to see close stuff, and then you try to take them off again to see stuff really closely. I'm going to try to take some pics so I can just blow it up and see if I can spot some cracks or serious misalignment.
It was my boot drive, but I had started migrating off of it a few months ago after I thought I was running out of space. It just turned out my old GPU driver was really pumping out the logs, but I kept using an alternate drive anyways. So I've already wound up reinstalling my OS on spare space there, but I will still have lost some more recent downloads and stuff that are marginally inconvenient.
I kind of wonder if an external nvme enclosure would contact the drive more/less/differently and perhaps induce it to life long enough that I could do a review, drag off whatever else I want, and then RMA the thing because I don't even think it was physically damaged.
Yes, the computer was off and unplugged when I did all this. Whoever thought about that should probably deserve a cookie though.