    AST RESEARCH, INC.         TECHNICAL BULLETIN #0875              10-15-93

                         DESKTOP SYSTEMS POWER SUPPLY ISSUES

    PROBLEM:       Certain desktop systems experience intermittent hangs during
                   power up. The symptoms are: the display is corrupt with a
                   white or blue screen, or random characters appear. Also, some
                   systems may experience intermittent failure of the floppy
                   drive.  These floppy drive errors occur randomly.

    CAUSE:         The cause of these symptoms are power supplies manufactured by
                   Delta.  These supplies contain a defective component which
                   causes ripple voltage on the five volt line, which disrupts
                   the operation of the system in the manner described above.

    AFFECTED
    SYSTEMS:       The following systems should be checked for the correct
                   revision level of power supply if they exhibit the above
                   symptoms and their serial numbers are below the numbers listed
                   below.

              AST                            SYSTEM SERIAL
          PART NUMBER    DESCRIPTION         NUMBER IS BELOW

          501126-XXX     Premmia             USD 6001026
          501127-XXX     Premmia             USD 7001087
          501128-XXX     Premmia             USD 8001032
          501129-XXX     Premmia             USD 9001059
          501204-XXX     Premmia             MTUSR7001141
          501278-XXX     Bravo               MTUSB1001459
          501220-XXX     Advantage Plus      USW2006274
          501221-XXX     Advantage Plus      USW3022105

    SOLUTION:      The system should be serviced as described in AST Technical
                   Document FCN #0097.