Warning, I'm a technician with some experience. Even with this I still get shocked, cut, burned and otherwise injured in the course of my work. Working with electricity and water apropos to these ice machines is a potentially deadly combination to the novice or inexperienced. Please consult the services of an experienced technician if there is any doubt as to your ability. Parts on this unit can be pricey, so don't just replace these without testing. This is not a comprehensive manual to diagnose, repair, or refurbish these machines. It is theory only in very abbreviated form.
When most techs and customer think of an icemaker, they think of the apparatus inside their refrigerator that fills with the tray with water, freezes, and harvests the ice by means of heating and dumping, or twisting a tray. Many import standalone icemakers also use this principle and truth be told there are drawbacks. The ice from these will pick up the taste from anything in the refrigerator. The cubes will retain mineral content from the water, causing taste and appearance problems.
The Kitchen Aid/Scotsman/Whirlpool/GE/etc is not like the imports or the icemaker you have in your fridge. These are found in bars, hotels, and even in some residential homes, offices and even gyms. These supply, fresh, clear, wet, and great tasting ice that's clean despite the claims made otherwise. to make this happen requires some technical wizardry to accomplish, Unlike the cheaper imports, these use more moving parts, and have been around since the 1950's. These use a cooling plate to freeze water that circulated over it by means of a pump. This pump takes water from a reservoir that is inside the machine and through the means of a distributor, evenly waterfalls this over the cooling plate. As this happens, the ice thickens into a slab; at a predetermined time, the harvest thermostat causes the cooling plate to heat. The result is that the ice slides off the plate and passes through a heated wire grid, which cuts this slab into cubes and they fall into a bin. The bin and reservoir both drain into the bottom, As the ice is not insulated, it melts at the bottom and drains, keeping the product fresh and the bin clean. Another happening is that once this water drains, it either goes directly into a floor drain or into a condensate pump.
Again, this is a very abbreviated view of how these work.