The dust of the environment was tought, but with a good maintaince schedule, Blow the dust out of power supplys and motherboards once a week, I could get a year or more out of a unit. The killer was keyboards, plant employees were tought on them banging the hell out of them, and some weeks it was two or three keyboards a week. Wen they announced our plant closing the keyboard count skyrocketed like 8-10 a week. At the first hint of trouble they went into the trash. We had talked about touch screens but the production workers still fount time to break them, so it worked out cheaper to use standard keyboards. I used to blow those out twice a week.