FCO DSRVB-F001, DECSERVER 200′s w DEC423 exhibit errors

This Field Change Order (FCO DSRVB-F001) addresses critical operational issues with DECSERVER 200 models DSRVB-BA and DSRVB-BB, particularly those below Revision C1 utilizing DEC423 interconnects.

The affected servers exhibit symptoms including artificial login attempts, excessive framing and port overrun errors, locked ports, and server slowdown due to false logins. These problems are specifically triggered when a user terminal connected via DEC423 data leads is powered off or left unterminated. This condition causes signal cross-talk or electrical noise to be misinterpreted as login attempts by the server's 5180 receiver chip.

The solution involves replacing the problematic DSRVB-BA and DSRVB-BB units with new ones provided in an EQ Kit. The rework instructions detail the process of locating the faulty server, obtaining customer permission, safely removing the old unit, installing the new one, and restoring power. Proper operation of the new DECserver 200 is then verified by checking the status of its four Light Emitting Diodes (LEDs) after power-up, following a self-test and down-line load process. The estimated installation time is 1.0 hour. The FCO was released on June 19, 1989.