Objective: To stabilize a platter that has suffered severe physical gouging from a read/write head, preventing further destruction during data recovery.
Overview
A head crash occurs when the read/write head physically plows into the spinning platter, shaving off the magnetic coating. This creates a ring of destruction called a concentric scratch and generates highly abrasive metallic dust inside the drive. While scraped data cannot be recovered, the surrounding areas can often be saved if the drive is stabilized.
Operational Steps
- Debris Evacuation: Vacuum the internal drive chassis using a specialized ESD-safe micro-vacuum to remove the metallic dust generated by the crash.
- Microscopic Mapping: Place the platters under a high-magnification optical microscope to map out the exact radial boundaries of the physical gouges.
- Burnishing (Edge Smoothing): If a scratch has raised sharp metal ridges (burrs) on the platter surface, technicians use specialized micro-abrasive burnishing tape to gently smooth down the raised edges. This prevents a replacement head from clipping the burr and crashing instantly.
- Targeted Sector Exclusion: Document the exact physical location of the damage. This mapping data is fed into data recovery hardware (such as an PC-3000) to instruct the drive to skip those damaged zones entirely during the imaging process.
Common Risks & Failures
- Instability: Burnishing is a high-risk operation. If the platter surface becomes uneven, the aerodynamic "air bearing" that lifts the heads collapses, causing an immediate secondary head crash.
- Rapid Head Blindness: If even a tiny trace of metallic dust remains on the platter, it will instantly destroy the replacement head stack upon spin-up.
