Field Change Order: 2016 Date of Issue : 18/5/90 Applicable to : Archimedes 420/1 (AKB42 0383,200( and Hard Disc Drive Upgrade (AKD52 0376,240) Reason for Issue: Variable mains noise immunity of these drives can cause low read/write reliability on systems subject to an electrically noisy environment. Types Affected: Any unit fitted with Miniscribe 20MB ST506 Hard Disc Drive type M8425 Description of Change: 1. Fit plastic insulator (0283,219) between hard disc drive and drive bracket. 2. Use plastic screws (0884,145) to secure drive to bracket in place of existing metal screws. Claim Procedure: N/A Rework Doc. Reference: FCO Credit Rate: For Info only Special Instructions: