    AST RESEARCH, INC.             TECHNICAL BULLETIN #0893               2-16-94

                BRAVO/ADVANTAGE! EXPLORER NOTEBOOK TRACKBALL PROBLEMS

    PROBLEM:       The cursor will skip or move erratically when the trackball is
                   used.

    CAUSE:         There may be dust, dirt, or oil on the trackball itself, on
                   its supports, or rollers.

    SYSTEMS
    AFFECTED:      Bravo/Advantage! Explorer Notebook.

    SOLUTION:      Clean the trackball, rollers and supports as described below:

                   1. Remove the trackball ring.  This is done as follows:

                      a. Insert the tip of a ball-point pen into one of the two
                         circular indentations in the ring.  WARNING! DO NOT use
                         a paper clip or other sharp metal object.  You will
                         damage the ring.

                      b. Press down lightly and turn the ring counterclockwise
                         approximately 1/4 turn.

                   2. Tilt the system toward you and let the ball and ring drop
                      into your hand.

                   3. Moisten a cotton swab with isopropyl (rubbing) alcohol.
                      The swab should be moist, but not wet enough to drip.

                   4. Wipe the rollers and trackball supports in the trackball
                      enclosure with the swab.  Clean them but do not soak them.

                   5. Wipe the ball with a dry cloth to remove dirt and oil.  DO
                      NOT wash the ball with water, alcohol, or any other
                      cleaners or solvents.

                   6. Replace the ball.

                   7. Replace the ring.

                   8. Secure the ball and ring by using the tip of the ball-point
                      pen, to turn the ring clockwise until it stops.