All six display units (DUs) blanked with a selected instrument approach to a runway with a 270-degree true heading, and all six DUs stayed blank until a different runway was selected. The Integrated Standby Flight Display (ISFD) and Heads-Up-Display (HUD) remained operational during this failure of the primary flight displays. The investigation has traced the behavior to a combination of common display system (CDS) block point (BP) 15 software in the DEUs and U12 or later software in the flight management computer (FMC). The investigation revealed that the problem occurs when this combination of software is installed and a susceptible runway with a 270-degree true heading is selected for instrument approach. Not all runways with a 270-degree true heading are susceptible; only seven runways worldwide, as identified in this AD, have latitude and longitude values that cause the blanking behavior. If CDS BP15 software and FMC U12 or later software are installed, all six DUs can blank when a susceptible runway with a 270-degree true heading is selected.