Those who enjoy doing a lot of sewing know there is not much that is more frustrating than a sewing machine that is not working as it should. While you often use just the regular straight stitch, occasionally you want to use the zigzag stitch. When the zigzag stitch is not working, you cannot do many of the stitches that are preset on your sewing machine, including buttonholes. Before taking your sewing machine to a professional, try fixing the problem yourself.
Read through your sewing machine manual and make sure that you have the correct settings for sewing a zigzag stitch. Set the proper stitch length and width as instructed.
Try some of the simple things first. Remove the bobbin plate using a screwdriver and then remove the bobbin. Clean out any lint that may be under the bobbin and which may cause your zigzag stitch not to work. Replace the bobbin and the bobbin plate and test your zigzag stitch.
Follow the directions in your sewing machine manual and oil the components of the sewing machine that rub against each other, as a lack of lubrication can prevent your needle from moving back and forth.
Reset the timing, which affects how your presser foot and feed dogs work together, by adjusting the cam of your sewing machine. Look at your machine's manual to find the exact location of the cam, usually at the back of your sewing machine. Loosen the screws in the cam and turn it clockwise to increase the speed or counterclockwise to reduce the timing.
Check the tension on your sewing machine, as too much tension may pull the threads too tightly and loose tension may not pull the threads tight enough. Set it at the middle range and test it from there, trying to make a zigzag stitch using a greater or lesser tension.
Take your sewing machine to a professional repair shop if you have tried all of the other steps and still cannot sew a successful zigzag stitch.