Abstract: Employee #1 and coworker, service mechanics, were assigned to do a complete maintenance check of the air-handling units at Langston Hughes Elementary School. Two units were completed. As they started the third the coworker did some initial tests by turning the unit off, then on, then off again. Employee #1 was supposed to test the tension of the belts, which were behind a full guard. Employee #1 misjudged the fact that the belts had stopped moving which they had not. When he reached around the guard to test the tension the belts, he caught his finger pulling them into the pinch point amputating the top joint of his little finger. His other three fingers were severely cut and one was fractured. Other mechanics stated that the guard was supposed to be removed when loading on the belts. The inspector believes that employee errors caused the accident to occur.