A common refrigeration equipment service problem occurs when an evaporator or its drain pan becomes completely engulfed in ice, and the technician needs to de-ice them. Normally this is a relatively easy but time-consuming task. However, the tech needs to be patient; it can become a nightmare if care is not taken.
Never use an ice pick, screwdriver, or similar device to remove ice from a coil. This is just asking for serious trouble. It doesn't take much force to puncture one or more of the tubes within an evaporator, and the relatively simple repair turns into a major one. The technician now has to repair the original problem as well as repair the puncture in the evaporator if possible; sometimes the entire evaporator must be replaced.