The simplicity of the mechanics of a sewing machine makes it easy to troubleshoot problems without much mechanical knowledge. Many sewing machine brands have a 25-year warranty on the head, and may not need a professional repair in that time frame. The American homemaker has been able to maintain a sewing machine in working condition with easy repairs and adjustments. You can do your own troubleshooting and keep your sewing machine operational for years. Doing it yourself can also save time and money.
Check the power source if your sewing machine will not start. Make sure the cord plugs into an active outlet and that the sewing machine is on. See if the light comes on to be sure that power is getting to the sewing machine. Push the wheel in to close the bobbin-winding operation. Once you are sure you have power, turn the sewing machine off to work on it.
Oil the sewing machine if it clatters or grinds. Use sewing machine oil or a 3-in-1 oil placing a drop in the oil ports as shown in the instruction guide.
Refer to the instruction manual to check the threading of the sewing machine. Place a spool on the pin so thread comes off the spool in a counter-clockwise direction. Use the thread guides to thread across the top, down to the tension control, back up to the arm and down along the needle shaft.
Replace the needle. The needle may be bent, may be an incorrect size or was installed incorrectly. Sewing machine needles have a flat side, and that side should be in position according to the instructions for your sewing machine.
Check the bobbin. Remove the bobbin under the faceplate and take out all parts that remove easily. Clean the bobbin area with a paintbrush or makeup brush to remove built-up lint and threads. Reassemble the bobbin area parts and the bobbin, checking the bobbin for even winding. Make sure the bobbin thread is in the guide in the bobbin case. Turn the machine on.
Check the tension. Sew a seam in a scrap of fabric by sewing on the diagonal. Remove the scrap and pull the fabric with both hands on the diagonal to test the tension of the stitching. If the threads do not break, or if both threads break at the same time, the tension needs no adjustment. If one thread breaks, or one side is loopy and the other is tight, the tension needs adjusting. Adjust the tension on the front of the sewing machine by using the tension dial—a round knob with numbers. Adjust the bobbin tension with the use of the screw on the bobbin case. Make slight adjustments and check the tension again with the scrap of fabric. Your troubleshooting should fix your sewing machine for miles of use.