AST RESEARCH, INC.           TECHNICAL BULLETIN # 0964              7-27-94




                               ADVANTAGE! MODEM NOISE


PROBLEM:        AST-built modem, (P/N 202626-001), which interfaces with the
                Sound Blaster card for voice mail compatibility in Advantage!
                systems, produces a great deal of system noise audible on the
                speakers, if the volume is turned up all the way on both the
                modem and the Sound Blaster.

CAUSE:          Because the audio signal is amplified by both the modem and the
                Sound Blaster card, it is possible to create the situation
                where there is excessive amplification by having both volume
                controls set at a high level.  This will cause system noise,
                which is not normally audible, at an objectionable level.

SYSTEMS
AFFECTED:           AST                                              REVISION
                PART NUMBER     DESCRIPTION                           LEVEL

                501416-XXX      AP486DX2-50                             All
                501417-XXX      AP486DX2-66                             All
                501418-XXX      AP486SX33                               All
                501419-XXX      AP486DX2-66                             All
                501420-XXX      APL2486DX2-50                           All
                501421-XXX      APL2486DX2-66                           All
                501434-XXX      ADV486SX-33                             All
                501438-XXX      ADV486DX2-50                            All
                501445-XXX      AP486DX2-50                             All
                501449-XXX      ADV486SX2-50                            All

SOLUTION:       To adjust the sound on the sound board:

                1. Run the sound file.
                2. While the sound file is running, adjust the volume control
                   on the sound board to a comfortable level.

                To adjust the sound on the modem:

                1. Set the modem volume to the lowest level
                   (counter-clockwise).
                2. Turn the volume control up a quarter turn (clockwise).

                You may need to adjust the volume slightly during the next
                incoming call.

                If the problem is not resolved after following the above steps,
                you may need to replace the printed circuit board assembly ISA
                adapter on your system with revision E or higher (P/N
                202626-001).  See FCN 0148 for more details.