FCO 64XMX-0002, T2015, T2015-YA and T2017 Module Replacement

This Field Change Order (FCO 64XMX-0002) details the procedure for replacing T2015, T2015-YA, and T2017 CPU modules in all 64XMX systems. The FCO addresses several critical issues, including instruction execution failures (e.g., MOVC5/CMPC5 with zero length), console/diagnostic ROM incompatibility with Vector options, PC misalignment during multiprocessing, VC chip instruction resending, and intermittent system interrupts due to dendritic growth on T2015 modules. For T2017 modules, it rectifies problems such as Load/Store chip hangs, signal integrity issues (undershoot/ringing), architectural specification breaches, and data integrity/process abortion in dual Vector configurations under heavy loads.

The solution requires replacing all T2015 modules below Revision "L", T2015-YA modules below Revision "D", and T2017 modules below Revision "J" with updated modules (EQ-01591-01, EQ-01591-05, and EQ-01591-02, respectively). The installation process involves a full system shutdown, recording current system configurations (boot specifications, serial numbers), carefully removing and installing modules using ESD procedures, powering on and verifying self-tests, restoring recorded system configurations to the new modules, and running extensive VAX Diagnostic Supervisor tests. The entire procedure is estimated to take one hour and concludes with updating site management guides and reporting the FCO activity.