tajima tfmx-iic 1502 help

I just got an embroiderer job and the machine I am using is a tajima 1502. the instructions are very vague. I am trying to backup a couple stitches after a thread break but when I back up(by holding stop) and hit start, the machine moves forward as if its just going forward but its not stitching until it gets to the place it ended at. I have a gap I need to fill and i can't figure out why it won't stitch from the point I back up to.
thanks in advance...
Peg

Flick the switch in the head so the red light comes on once you have backed up as far as you need to

you need to change setting from forward to backward on controller head. without the panel in front of me...not sure if it is the C or D key. It will say frame forward or backward. change to back.