Y-Axis AWOL

Hey All,

My SD2 has been pretty great over the past 9 months, but as of recently, I've had some problems.
Primarily, the Y-stepper motor "skips" about a half-hour into a print. I called HQ for advice, and was told to adjust the Y motor. I did, and it was as taught as it was when I corrected it last August. That didn't work, and i was told to adjust my baud rate. That shift the problem from negative y-shift to positive y- shift.
I called again, and was told to adjust the Y screw in the Motherboard by 1/16th of a turn clock-wise.
I did, and now i can't get the cartridge to move in the Y axis AT ALL.
Help? Thanks.