Un cortocircuito può danneggiare un disco rigido?

Everything was working fine until one day when my computer would shut down a split second after the power button was pressed. All the fans would start spinning and the lights would come on, but then everything would go dark half a second later. After this happened, pressing the power button had no effect. The only way to get my computer started again was to unplug the power cord, then plug it back in.

I suspected the power supply was the cause at first, so I bought another one, but I still faced the same issue. I unplugged everything and reseated the RAM/GPU and drives. After doing that, my computer booted and I thought I was good to go, but then I noticed my secondary hard disk drive was no longer working.

It was not visible in BIOS or Windows. I replaced the hard disk drive with another one, but after a while, the original issue came back. So I reseated everything again and was able to boot back up, but to my horror, the new hard disk drive was dead as well. At this point, I thought maybe something was shorting the system out, so I took everything out of the case including the motherboard. To my surprise, there was a loose screw stuck between the back of the motherboard and the case.

Yes, it is definitely possible. For example, the screw could short out the +5V line to the +12V line and fry the hard disk drive’s onboard controller.

Yes, it can. A hard disk drive can fail indirectly. Hard disk drives that have been used for a long time tend to fail at the next reboot/startup (caused by a short circuit or normal power switch). Other possibilities are a surge from a wall socket or induction after a short circuit reached the hard disk drive’s electronics or controller. Note that there should be all kinds of fuses, diodes, capacitors, and shielding in place so that an electrical problem does not spread, but cheap hardware tends to be commonplace.

There is also the problem of (logically) corrupt sectors if the power fails while writing. This should also be covered by the hard disk drive, spinning just long enough to finish writing the data, but it may not succeed though. Such corruption might result in transient read errors, and it might require some disk repair work or special tools to refresh the sector(s) in question.

It is typically hard to know the exact reason, but a screw connecting the main board’s power lines with a grounded chassis (or with each other) does sound like a probable cause for a short circuit, which could cause damage to the hard disk drive (which it should not do).

I do want to add that your computer’s “symptoms” could also mean that the hard disk drive died, then short circuited the computer, or that the power supply unit was overloaded with the hard disk drive’s demand for power at startup.

Yes! I have lost two hard disk drives due to a short circuit. It was quite spectacular. An integrated circuit at the bottom of one exploded, resulting in a loud bang, a little fireball, and a nice crater.