To repair an old White sewing machine, find the part of the machine that has stopped working, such as the needle, feed or foot pedal. Inspect the outside of the machine to eliminate any obvious problems, such as thread tension or bobbin placement.
Inspect the needle, and ensure it is properly threaded. When the thread spool runs out, the needle automatically stops until the spool is replaced. If the needle is broken, replace it, and make sure it did not break because it was an inappropriate size for the material weight or because it was not properly fastened or screwed into the machine. If the needle still doesn't work, check the settings for the stitch length to make sure it is not at zero. Another common problem is the presser foot pressure setting changing from normal to low.
If the machine is making strange noises during use, clean it thoroughly with a small cleaning brush to dislodge debris caught in the mechanisms. You may also need to oil it with sewing machine oil. This requires taking apart certain components of the machine. The user manual diagrams specific lubrication points and instructions. If the machine is still not working, check the software program if it is a digital machine, or take it to a professional.