DeWalt manufactures cordless power tools and a range of accessories, such as batteries and chargers. DeWalt battery chargers are sealed units that require specialised tools to open, as chargers must comply with electrical safety regulations. DeWalt battery chargers don't contain serviceable parts, and tampering with a charger invalidates the warranty and, more importantly, is potentially dangerous. However, some DeWalt battery chargers contain a fuse, so if you find your battery charger isn't charging your battery, there's a good chance you can repair it by replacing the fuse. You can find a fuse at an electrical supply store.
Make sure your DeWalt battery charger isn't plugged into the electricity supply. If it is, unplug it before proceeding.
Check the Dewalt battery charger to locate the fuse cover. The position varies, depending on the type of charger, but the cover is usually on the base. The fuse cover is labelled accordingly. Not all DeWalt battery chargers have replaceable fuses.
Access the fuse by removing the fuse cover. It may be attached with a small screw, so use a suitable screwdriver to undo the screw. If it clips in place, find the small raised area on the side of the cover. Insert a small flathead screwdriver under the raised area and gently lift it off.
Pry out the fuse with a flathead screwdriver. The fuses are small and are difficult to remove with your fingers.
Put the new fuse into the fuse holder. Position it above the clips, then carefully press down using your fingers until you hear it click into place.
Replace the fuse cover. If you lifted it off, simply press it into place. If the cover screws on, replace the Phillips screw and tighten using a screwdriver.
Put your battery in the DeWalt battery charger and plug it in. You can tell it's repaired if the charging light illuminates.