What's Inside A Harddrive

One of my harddrives broke because of a faulty power supply. Instead of throwing it away, I thought I would open it just to see what was in it.

pcb top
pcb underneath
This is the circuit board (from above and below). This was probably the only part that was broken, but to get hold of another would have been too much trouble.

uncovered disk

uncovered disk
The inside of the drive.

how far the arm moves

how far the arm moves

The above two pictures show the extent to which the arm moves. It doesn't reach right across to the edges of the disk.

the spinning disk

What the disk looks like spinning...

box of miniature balls

This is at one end of the drive. It seems to be a box of miniature balls. They look like they may be made of lead. I have no idea what they do, even though it would take me ten seconds to find out on the internet.

first disk taken out

There were two disks in this drive, although there was space for one more on the spindle. The disks feel like they are made of glass, but are apparently metal. They are 1.3mm thick which is thicker than I expected. I thought they would be of a similar material to the disks inside floppy disks and very fragile.

Their sturdiness shows that technically it wouldn't be that difficult to recover data even if the external drive and electronics were completely destroyed. A new circuit board could replace a broken one, but if the worst came to the worst the actual disks could just be put into an identical empty drive. They would probably have to be removed with slightly more care than I used though.

There are thick metal spacing rings to keep the different disks apart.

first disk taken out

Another picture of the first disk taken out.

first disk taken out

The second and final disk waiting to be removed.

both disks on display

I carefully removed the second disk by ripping the arms out of the drive with pliers and forcing it out with a screwdriver.

the empty case

The empty case with the broken off arms.

The underneath of the empty case, where the circuit board was originally.