Stompdoctor is a company that performs repairs and maintenance on guitar effects pedals and electronics. Stompboxes, or effects pedals, are effects units designed to sit on the floor or a pedalboard and be turned on and off with the user’s feet. They typically house a single effect. The simplest stompbox pedals have a single footswitch; one to three potentiometers for controlling the effect, gain or tone; and a single LED to indicate whether the effect is on or not (in Wikipedia). Sometimes they brake. When they do, you may need to call the Stompdoctor.