@Fzabkar and Mabkay
Let me tell you this from direct practical experience: I had a 1TB MyBook that would seemingly at random lock up the system and itself. Also from time to time the disk would just disconnect itself from the Windows Explorer. The drive letter would simply disappear like as if I pulled out the USB cable. The problem would go away if I disconnected and reconnected the drive, both USB and power cables. The problem would keeping coming back sooner or later. Well, I got around to running HDD Regenerator and it found a narrow swath of about 20 consecutive bad sectors, right in the middle of the disk.
I had HDD Regenerator go over the entire surface, took about 16 hours. I had it test the surface. It did not find anything more than the 20 corrupt sectors. To completely regenerate a 1TB disk at USB 2.0 speeds would have taken 460 hours! So I settled a for a thorough scan instead.
Then I zeroed the drive with WD DLG.
And I full formatted the disk with the standard windows explorer window.
And now, the disk is 100% healthy, been that way for quite some time. No more seemingly random disconnects or slow-downs or anything. Perfectly reliable.
A few months later I got to looking at my logs and discovered that the few files affected by those damaged sectors had a time/date stamp curiously close to the time of a total system shutdown and re-start. And a few days later after those files were saved I had to replace a USB hub that also refused to go into 2.0 mode. And to top it all off I checked the UPS logs for other systems (this system was not protected) and noted power fluctuations to the minute that matched with the suspect files. And thus the bad sectors. I checked a few more windows logs and file transfer logs too. And everything seemed to match up with the brownout conditions!! At this point I felt quite confident the reason for the disk failure was power related. I consider it a closed case and 1 disk saved from the junk heap.
I completely understand the electronics theory involved in power supplies and how it comes together to make a working consumer-level product. I’ve designed enough circuits over the years to positively tell you that the only solution to clean power is pure DC or a complete UPS that is isolated and does its own AC-DC-AC conversion; with a battery in the middle. These surge suppressor strips and stuff you buy at the dollar store only work against spikes. And even then their MOV’s take time to react. They also won’t filter all the resonances and harmonics present during a brownout.
Know that there are harmonics and all kinds of inductive nastiness when you’re powering an external disk and a PC from the mains during brown out conditions. You’ve got ground loops, fluctuating and sagging voltages, spikes & surges, harmonics & resonances, everything! A nearby motor can have its field collapse with the sudden loss of power, and if it is still connected to the mains nearby it can introduce its own dirty power for a few microseconds.
Ideally the tiny power protection circuits and regulators scattered throughout your systems internals would supply a perfect 5V and 12V to the hard disk and other components. This isn’t the case all the time. They’re mostly there for dealing with connector noise and internally generated noise. They’re also quite busy setting up the voltage levels in the first place. And any outside disturbance will affect them. You can take that to the bank.
Furthermore, be aware that the frequency of magnetic reversals at the tip of the head writing element is close to 1Gb/sec. And did you know that the data bits on your disk are analog?? Yes that’s right! The signal put out by the head is an analog wave that bounces up and down smoothly. Not the zeros and ones depicted in layman’s illustrations of how disks work. This is all a very delicate operation! Any mistake or power fluctuation can render a short number of sectors “weak” if the disk is conducting write operations. This is sometimes enough to trip-up the background error checking that most WD disks do as a matter of course to protect your data. The disk can endlessly try fixing a weak sector and in the proccess cause your system to lock-up, until you disconnect the “faulty” usb drive. This can give the impression of a failed disk.
So if power problems have caused your failure, this HDD Regenerator could be one way to fix it. Assuming that’s what really happened. You need to know that for sure. Because, HDD Regenerator won’t fix bad hardware.
Enjoy!
