Loud clicking, grinding, or ticking noise.
In some cases, a failing hard drive will generate loud clicking, grinding or ticking noises. This is an indicator that the hard disk drive has bad sectors or is mechanically failing. The noise is generated by the actuator arm returning to the same position on the platters in an attempt to read the data. This can cause severe damage to the platters and cause data loss. If the computer is indicating this type of failure, it is highly recommended the computer be turned off immediately.
Note: An External Hard Disk Drive provides a secondary source for data storage. External hard disk drives are also subject to failure. When you experience an external drive failure, part of the recovery procedure is to remove the outer case which houses the hard drive. This is should always be performed in a Clean Room facility.