A few weeks ago I opened the cover of a useless drive and then screwed it back on for what else.... fun. The result was the drive still worked. I was shocked because I thought once the cover is opened, dust gets on the platters and it's useless.
I believe running the drive without a cover didn't work until I replaced the cover.
After dismantling a few drives over the years, I've learned they only have electronics, a motor, platters, and heads (ignoring the coil and magnet). My assumption is the platters can't go bad unless the heads scratch them. The heads don't seem like they can break, although maybe the weight of the head pulls on the arm and/or arm can get weak over time and (as it was pointed out) stick to the platter.
The motor (in my experience) always seems to spin. This leaves the electronics which I imagine could develop cold solder joints (I've seen enough cold solder joints in my days of repairing), but this would mean the bad drives I've experienced all had bad solder joints in places that allowed the drive to spin, but not be seen by Windows.
With all this being said, if the motor doesn't come up to speed quick enough, I assume the electronics aborts the operation. But if the motor spins long enough and heats allowing inertia to get the motor spinning faster and faster, I'd assume a USB reconnect would allow the drive to be seen.
I know a hard drive has very tight tolerances, and millions of '0s' and '1's being read/written at very fast speeds, but seems basic surgery could be done to get a drive back to a working state.
I do have a 2.5" laptop drive that isn't mine, and MAY contain pictures I'd like to transfer (it's a long story, but bottom line is: it's a drive that may or may not have stuff on it). Unfortunately I hear the head swing back and forth and then come to a rest. Although research told me this wouldn't work, I tried buying a replacement PCB, however, as research stated, it didn't work. I believe due to a chip containing information on how it wrote the data on all the platters. This chip would need to be removed and installed on the new PCB.
After various tactics to get the drive working (including the freezer trick), I removed the cover to discover the drive didn't spin at all. After looking around, I learned the metal cover connected two screw holes electrically. Once I touched a wire to two screw holes (with the cover on) the drive spun, however, this only gave me a visual on the heads moving back and forth until they gave up.
The drive is still in my possession and I'd like to get the data off this. I'm keeping the drive in hopes of one day technology advances thus allowing me to get the data. Unfortunately not knowing whether the drive has anything valuable doesn't give me a reason to send it to a pro.
During research for this drive, I also learned someone removed platters from a bad drive and installed them in a good drive. He did this by placing tape around the edges of the platters to keep them aligned. From what I read about this Western Digital drive, as I typed above, the drive needs the electronics to know where data is or how it's aligned throughout the platters.