Most of the time it is a moisture issue. Tap water is a very poor conductor of electricity, add soap and it becomes an excellent one. WD-40 displaces (gets rid of it) moisture. It won't hurt anything and should help with any blade lubrication issues you may have (lack of oil on the blades). #1 phillips screwdriver and a can of WD, use the straw. Apply liberally, wipe down excess from the exterior and enjoy your trimmer. Hands down the best trimmer I have ever had. Keep the thing dry it's not designed to be used underwater goof!