I had a power outage a couple of weeks ago and when the power came back up I noticed that one of my servers made a strange beeping sound that I had not heard before.
My first thought was that all the data was lost. I knew that there are professional services that may be able to recover data but that they are typically very expensive. This was a private server and most of the data had been backed up anyway so paying that sort of money to salvage the disk was not an option I considered.
As it turns out, this particular issue is actually quite simple to solve by almost anyone. The only thing you need is a T6 torx screwdriver, a clean surface, a toothpick, a steady hand and some luck. It also helped that the data was not extremely valuable for me. I would perhaps not recommend this procedure if you care very much about the data on the disk. In that case it may be better to pay up. You can definitely make things worse. Don’t say I didn’t warn you.
Note that these instructions only apply if the disk beeps like in this audio clip. If the disk makes a more mechanical noise then the error is caused by some other issue and you should not follow these instructions as they could worsen the situation.
When the disk is beeping with a steady period (typically around 1Hz) it typically means that the disk head is not in its parked position when the disk is about to spin up. Normally the head moves away from the disk before the disk is shut down and does not move in over the platters until they are spinning at full speed. The rotating disks create an air flow that acts as a cushion for the heads so that they do not touch the surface. If the heads are over the platters when the disk is off then the disk will just refuse to spin up.
To fix the issue one just needs to open the hard drive and gently move the head to its parking position while at the same time turning the platters counter-clockwise.
The lid covering the internals of the drive is usually held in place by seven screws. Six of those are along the edge and readily visible. The seventh is in the centre of the disk head arm and normally covered by a sticker.
You may be concerned about opening up the disk outside of a proper clean room. While it is true that the internals of the disk are delicate you should not be too concerned. The disk is constructed to be able to handle small amounts of dust that could be released from the internals of the disk during operation. The white item in the bottom right on the photo is a filter that is there to catch dust particles. The heads do not leave their parking position until the disk it at full speed and their speed creates an air flow that should remove any dust from the disk and deposit it on the filter.
When you move the head back it may feel like it is stuck at first due to static electricity. Just rotate the disk counter-clockwise while you gently move the arm back and you should be fine. I found that a toothpick is a good tool for this. The image below shows how the arm should be positioned when you are done. Then just put the lid back on and keep your fingers crossed.
If it worked then congratulations. But make sure to copy the data to a new disk and consider the old disk used, never to be trusted again.