The light on this machine is fragile because the housing is made of bakolite. The switch wobbles free and becomes part of the shorting problem as well. With repeated use through the years, it deteriorates, cracks, and shorts. I had a similar experience with this machine. The good news is that it is very easy to replace once you take the top off. The lead wires need to be carefully removed since they thread through the upper housing, but if you take your time it is fairly straight forward. You'll have to get a replacement light housing for it, but the good news is that they aren't too hard to find. Then it will work like a dream. Wonderful machine.