X-axis belt slipped and now need fx2_usb_test.exe to calibrate

My X-axis belt slipped on a Bio-Rad CFX Real-Time PCR Detection System and now I need fx2_usb_test.exe to calibrate according to the Service Manual. This software stores the X position. Mine must be off a little. I'll fiddle it back and forth with hopes of finding the original start. If not, I need this pesky software to store the start position. Any one out there with experience? So close!!