An ST1200MM0088 out of a PowerEdge R730, slot 3, clicking, with a RAID 5 set of six that could not rebuild without it and a second drive predictive
Two heads had failed and the controller had marked the drive failed; the owner powered down instead of rebuilding. The clicking drive had a matched head stack fitted on the clean bench and was imaged on the SAS imager head by head; the predictive-failure drive was imaged too, with its weak areas last. Both images went back on fresh drives and the set rebuilt cleanly.
Illustrative example — replace with a genuine case