Second hard drive not showing up on PC

Hi everyone, I need some help. I have two hard drives in my PC, but one of them seems to be malfunctioning—or at least, it isn't showing up on the system. I've had issues with this PC for quite a while. When I first got it, for some reason, it would simply "go dark" while remaining powered on; the machine was running, but there was no video output, and the only way to fix it was to unplug the power cable. Regarding the hard drive: initially, it would appear on the screen where drives are listed, but it didn't show any storage capacity and couldn't be used. However, as time went on (and the "go dark but stay on" issue persisted), the drive stopped showing up entirely. Now, I don't know if it's still working or if it has failed completely. Could someone help me out?