Question on Knitking Compuknit III?

I purchased this used machine about 10 years ago, used it successfully, then let them sit about 7 years after some back surgery. I recently brought it out again, and after reading previous posts, I replaced the sponge bar and oiled the bottom of the carriages and the needle beds and bumps. The unit will now knit with a thin gauge yarn, but with many dropped stitches and issues. I have lowered the tension, and checked the needles, but as I am not proficient on the machines, I feel I am missing something. The tension seems tight to me, and also, the needles would not knit in the E position, as I was on the early lessons of the KnitKing book, which recommended 20 needles on each side at E, then every other one back to A. They would knit on B, but not on E, at E they squarely knocked into the unit that is screwed on (name escapes me now). I am quite proficient at embroidery sewing machines, but this is totally stumping me!