Talk about blowing up your machine, I changed a lightbulb with an auto light bulb. it blew up the bulb and now the new correct light bulb will not light, nor will the foot pedal work. I am afraid I have literally blown it up! I have at the repair man now. I hope he won't find that I blew up the brains or something. It is an old ("72, I think husquavarna Sweden) by viking. It belongs to my MIL so will fix it, but hope not too pricy.