Yamaha CS80

OK, I'm trying to tune my CS80, using Old Crow's instructions and the
copies he has of the yamaha adjustment procedure.

Here's my problem: on page six of the yamaha instructions, it states
that the 16 oscillators are divided into two groups 8 (M11 - M18
boards) for CH I and 8 (M21 - M28) for CH II.

But inside my CS80, the M boards are listed (reading right from left)
as  M4 - M11, then M15 - M22. I tried to start tuning assuming that M4
would be voice I of CH I. So I turned the instrument off for five
seconds, and then pressed A1 once. That should give me voice 1, right?
Yes, I had the mix selector on CH I. But, turning the pots didn't
really produce any noticeable change. How sensitive are the pots? Do
you need to turn them a lot, or just a bit? 

At this point, I don't know what voice I've been messing with, and I
hate to go any further, because the thing is reasonably in tune, just
one voice of CH I is out by over a whole step.

Suggestions are welcome, including good techs in Southern California
that don't charge an arm and a leg for tuning. I'm in Palm Springs.

Thanks, Bill.