Faulty Chip Resulting in Heavily Loaded Outputs

This Field Change Order (FCO KA43-0001) addresses a hardware defect identified in the VAXstation 3100 Model 76. Certain National Semiconductor 74F244 chips used on the KA43 System Module fail to stabilize under load, leading to unpredictable addressing and system instability.

Key Information:

• Product: VAXstation 3100, Model 76
• Required Action: Inspect 74F244 chips for the manufacturer and date code; replace the KA43 system module if the affected chips (manufactured by National Semiconductor in 1990, weeks 30-42) are present.
• Parts Required: KA43 System Board (EQ-01607-01).
• Important Note: The KA43 module is in short supply and must be returned for repair after replacement.