HP's vinyl-coated top, bottom, and side covers can become sticky with age due to deterioration of the vinyl. To address this:

• Remove the cover from the instrument. Wash it with mild dishwashing detergent and warm water to remove any dirt and grime. Scrub gently with a sponge to address any bad areas.

• If the covers are still sticky after washing, WD-40 can be used to break down the film. Repeat if necessary. Wipe it down thoroughly with a clean paper towel between each application.

• Use ispopropanol in the same way to remove the WD-40, but use it sparingly - alcohol can change the vinyl's appearance if overused.

• If available in your geographic area, a product called Mothers Back to Black, sold for automotive use, results in an almost like-new finish. Use in accordance with package instructions.