Hard drives are far from silent devices, but some sounds can indicate a serious physical fault has occurred or is on the horizon.

Inside a hard disk drive, there are magnetic platters that are spun by a spindle motor at speeds of around 15,000 RPM. A few nanometres above the platters are the read/write heads, situated on the tip of the actuator arm. When you power up a hard drive, you’ll typically hear a low hum, rising in pitch as the platters begin to spin faster and faster. When the platters have reached their full rotation speed, the heads will move into position. As the read/write heads leave their parked position, you’ll then hear a few bursts of scratching noises. This initial burst of noise should last no longer than about ten seconds, after which point the hard drive will quieten down significantly. Since the platters are still spinning, there will still be some noise coming from the hard drive – normally a faint humming sound – along with the occasional scratching noise as the heads move position. Different hard drives may vary, and some modern hard drives will be near to silent unless you have your ear up against them.

Any noise beyond a faint humming sound and an irregular scratching/clicking could indicate that your hard drive has suffered from, or is about to suffer from, a physical fault, such as a head crash or a motor failure.  

A hard drive’s read/write heads can fail, resulting in a repetitive clicking sound. Upon being powered up, the platters will start to spin, and once they are at full speed, the heads will attempt to move into position. If they are damaged or stuck, the attempt to move them from the parking area will result in a click. As the drive attempts to move the heads in position repeatedly, the result will be a regular clicking noise. A head crash – where the drive’s head has come into contact with the magnetic platters – will result in a constant grinding noise. The grinding noise you’re hearing is the head scraping away at the platter’s surface as it spins, so suffice to say you’ll want to immediately power down your drive. With a head crash, time is key, and the sooner you power the drive down and get it to a data recovery specialist, the higher the chance of you getting your data back is.

In the event of a motor failure, the hard drive’s platters will fail to spin, resulting in a beeping noise as the motor attempts to spin. Hard drive failure due to a seized platter motor is typically the result of a bump or knock, and it doesn’t even have to be a particularly big shock either; motor failure can occur when a drive simply falls on its side. Like most components in a hard drive, the spindle motor is delicate and vulnerable to physical trauma. A hard drive in a desktop computer is normally unlikely to suffer a motor failure due to its stationary nature. An external hard drive, on the other hand, can be moved about freely, and potentially knocked or dropped.