Try as many different combos as you can in order to isolate the problem. For example, try one of each stick in slots 3 and 4, two of the same in 2 and 4... 3 sticks in slots 2,3,4, etc. That MIGHT help you isolate the problem.
BTW, it's spiffy that you have voice that talks to you
. Most people have to decode beep patterns. I don't even have a case speaker