_ DEC-O-LOG for DHW4X _ DOL, DHW4X-F001, 54-20662-01 Module Feb 93 PROBLEM: The DHW4X option will "lock-up" or "hang" at intermittent intervals, depending on customer application, because of lost interrrupts caused by a failure on the rev. B03 DHW4X logic board 54-20662-01 to process data. Once "lock-up" occurs, any/all devices attached to the DHW4X cannot be stopped or cleared. FIELD EFFECTIVITY: This FCO applies to MicroVAX 3100 Models 30, 40 and 80 with a DHW41/42 asynchronous communications option that uses a rev. B03 logic board 54-20662-01. SOLUTION: Replace the revision B03 logic board (54-20662-01) with part rev. C03. QUICK CHECK: Look for revision C03 printed on the 54-20662-01 logic board. To determine the rev. level, the system unit must be disassembled and the 54-20662-01 logic board removed for inspection. If it is at rev. B03, this FCO is required. FCO KIT ORDERING EQ-01668-01 54-20662-01 Module FA-05002-01 FCO Document