I have a quantum cxl. It will sew normal stiches but it will not sew the decorative stiches

The needle shaft sticks to the curved arm and won't come down because a piece of plastic, about an eighth of an inch thick had broken from age. It prevented the shaft from staying up on the needle arm. Open the cover, try to stitch decorative stitch and see what I mean. Purchase a package of 4-10 by 1/2 nut and bolt pack. Screw the nut all the way onto the bolt. Using needle-nosed plyers, Carefully bend the curved arm slightly, and place bolt into the hole on the top of the needle shaft. Nut will keep it in place. Lowering the needle shaft using wheel, carefully bend arm back in place. Try decorative stitch. It should work. It does for me.

I looked at the little cards that came with mine (plastic see thru cards) after choosing the design pattern and putting on the correct foot (T). It said to lower needle into starting spot (bottom left corner of design) then push start. I played with mine a bit to get it to work. I also noticed that if I carefully gave the needle arm a very slight push down on the screw that you tighten to hold in the needle, it seemed to give it a little jump start. My machine is the Professional XL-150 which I do NOT have the manual for ., but everything refers me to the CXL model as the same.

Quantum cxl model 315402 nothing but problems.