Long Arm HDA's Exhibit Hazing Condition

This Field Change Order (FCO), numbered RA90X-F003, mandates a rework on RA90 disk drives equipped with long-arm Head Disk Assemblies (HDAs) produced before July 1989 (HDA date codes at or below CX926XXXXX and KB928XXXXX). These drives may develop a hazing contamination inside the HDA, which can trigger specific error codes during extended power-down situations. The solution involves upgrading the drive microcode to revision V26 or higher, which enables a 'spin-up retrack' feature. The document provides detailed instructions for determining if an HDA is affected, the required tools and parts (including a microcode cartridge), and specific hardware inspection and rework steps, such as checking electrical connectors and modifying the ECM module via etch cuts and jumper removal. Additional recommendations for addressing spin-up errors and a list of issues resolved by the V26 microcode are also included.