Rhodes Chroma Polaris

i finally did the memory upgrade on my polaris--- it was very easy. but upon doing all sorts of tests to prove its ok i noticed  that the touch sensitivity was out on  voice #1  -- It played fine but every sixth note would NOT play with a soft touch... just a harder one. I did the voice isolation test and indeed voice 1 would not play softly.  would this be an issue with a chip  or connection in Voice #1?  or  in the keyboard? I had cleaned all the contacts, all notes do play.