FCO DFMZA-1001, Composite link has problems w/error recovery

This Field Change Order (FCO) details a mandatory upgrade for all DFMZA-BA and DFMZA-BB units (DECMUX-II and MUXSERVER-100) to rectify system hanging problems stemming from composite link error recovery issues, particularly in route-through configurations. The upgrade involves replacing two specific UVEPROMs (23-318E5-00 and 23-319E5-00) on the DFMZA-BA/BB 54-15931-01 module, inserting them at IC locations E5 and E6, and installing a "C01" revision tag.

Successful implementation requires that DFMZA-BA/BB, DSRZA-BA/BB, and MUXSERVER-100 units are at firmware revision "C01" or greater. The installation process, estimated at 0.75 hours, necessitates the use of an Anti-Static Work Station and adherence to anti-static procedures. It involves powering down the Decmux II, disassembling it to access the PROMs, carefully replacing the old PROMs with new ones, reassembling the unit, performing a factory reset, and restoring the original system configuration.