In Teradyne’s Saturn HD tester there are 1080 slots/rack for HDD testing, with 12-18 racks per machine. During testing, slots fail and go offline, at which point the condition of the slot must be verified. In the past, this required removing the offline slots so diagnostic tests can be run on the bench, where there is a production test drive (PTD). The bad slots are sent for repair while the good slots are kept as spare parts. This process was both time and resource intensive. To improve this process, Teradyne has developed the In-System Verify (ISV) solution whereby instead of moving a slot from the tester to the PTD drive on the bench, we instead move the PTD drive to the slot inside the tester. This allows us to avoid removing the slot which may still be in good condition (even offline). This presentation will discuss the ISV solution, and its unique features that allow us to load the PTD drive to the input stacker of a production machine while the machine is running, without the need to stop the machine. The software handles moving the PTD drives to the target slots by automation and then sends the command to start testing. Once the test has finished, the automation will move the PTD drive to the next slots automatically. With this implementation, the number of slots removed from the machine is significantly reduced, and the number of verified slots per day increased significantly with fewer people due to process automation.