FCO CI750-1006, VAXcluster node randomly rcvs incorrect data

This Field Change Order (FCO CI750-1006), released in July 1988 with parts available in September 1988, addresses a critical issue in which a VAXcluster node randomly receives corrupted data packets originating from a VAX750/CI750. This data corruption occurs when the CI750 encounters a single or double-bit main-memory error on the VAX750.

The FCO upgrades the CI750 to Revision F1 by incorporating Engineering Change Order (ECO) L0009-MK003. The solution involves replacing a Microcode ROM (P/N 23-121C6-00) and/or an L0009 Module (Part Rev C3), depending on the existing L0009 module's revision. The installation procedure, estimated to take one hour, requires a system shutdown and careful handling of electrostatic discharge sensitive (ESDS) devices using a VELOSTAT kit. Technicians follow conditional steps: if the L0009 module is A1 or A2, the PROM is replaced; if it's A3, the entire L0009 module is replaced; if B2 or C3, no component change is needed. Post-installation, diagnostic tests (EVGAA/B) must be run, the system booted into the VAXcluster, and the activity reported on a LARS form. The FCO affects an estimated 2,600 units.