So, my entire machine is consistently plugged into a surge protector. All the same, a sudden electrical storm caused a total power down. After starting it back up, it can't find a relatively important Hitachi drive, but does boot. (I have checked UEFI, which also cannot see it.)

Weirdest of all, even with the computer off, the power supply off, and literally no connection to wall power, the case lights are still on.

That data is extremely important to me. Does anyone have a wager as to what's going on with my machine, and how I can recover? I'm more a software guy.

If it's relevant, my motherboard has the inscription MS-7641 VER: 4.0. Can't remember the specific model.

  • If you pull the plug the case lights may stay on for up to several minutes due to the power supply storing some electricity in its capacitors. That's completely normal. – SpiderPig Aug 3 '18 at 20:57
  • Did you try connecting the drive to another computer? – SpiderPig Aug 3 '18 at 20:59
  • Not yet on connecting the drive to another machine, I'm waiting for the lights to turn off before I discharge the caps with the power button and open it. Also, the light has been on for half an hour now, with no wall power. – Michael Eric Oberlin Aug 3 '18 at 21:16
  • It's now been over an hour, the light is still on, and, strangely, the optical drive could eject. I'm going to put a bunch of groceries away, unplug everything, and switch the surge projector out for the new one I just picked up. This is either wierd or hilarious, I just don't know yet. – Michael Eric Oberlin Aug 3 '18 at 23:13
  • OK. I just unplugged a usb 2 hub with external power, and it clicked off! Plugging it back in turned the light on again! I never would have guessed that it was USB back powering. I got that hub relatively recently, so there's a chance that this was always the case. The mystery of the hard drive remains, but if I solve this I'll put a detailed answer up. – Michael Eric Oberlin Aug 3 '18 at 23:17

Oh my freakin' God. I was right about it being something funny.

So, after I removed the USB 2.0 Powered Hub (as mentioned in the comments), the light and optical drive turned off. My machine was truly removed from any source of energy. I then swapped out my old surge protector for a new one (the brown-out alone is a perfectly good cue that I needed a new one anyway), plugged everything in, flipped my power supply main switch to off and held my power-on button down for sixty seconds to drain the caps (I know thirty was more than enough, but I wasn't taking chances with what was on that drive), flipped the power supply switch to on, and powered it back up.

Everything booted smoothly, and the drive-in-question (and all of my work) was visible again. I'm going to run a hardware check on the Linux side to be sure, and probably invest in some active online backup; but my best guess is that during the brown-out, my drive did not properly shut down, I was running Linux, and it is where my Linux root partition is. This may not have been an issue if it was truly powered down, but that USB back-power may have been tricking the drive into thinking that it was still powered on. Thus, for one reason or another, UEFI didn't detect it as a valid drive (or even one that physically existed).

That is largely speculation, but it fits the data. USB hubs are finicky creatures. Peace!

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