TQK70 Controllers Fail to Boot Standalone Backup

This Field Change Order (FCO) addresses an issue where TQK70 controllers (Revision A and B) fail to boot or experience significant delays (exceeding 60 minutes) when performing a standalone backup using certain copies of VMS Version V5.0. Field Service engineers are instructed to replace two EPROM chips (locations E27 and E28) on the M7559 module and update the board revision to Cx. The document includes detailed installation procedures, safety precautions against electrostatic discharge, and specific labor activity reporting codes.