after allot of checking tech sheets and info the only other thing I came up with on your machine isw that it could possibly have to do with the touchpad,
CHECKING KEYPAD OPERATION
¦ Check keypad ribbon tail for
¦ Check for loose connection to control.
¦ Check for evidence of contaminants or corrosion
around perimeter of the keypad, on the keypad ribbon
tail and/or on the keypad connector at the control.
¦ Perform keypad function check.
¦ For a final check (if possible), try replacing
control/keypad with a known good control/keypad to
identify where problem(s) persist. check these things and let me know, sorry about late reply, my granddaughter is sick and needed attending to. thanks Bryan