Customer reported a dripping bathroom faucet that would not fully shut off. Inspected faucet and confirmed worn internal cartridge was causing the leak. Shut off water supply, removed handle and trim, and replaced faulty faucet cartridge with the correct manufacturer-specific part. Reassembled faucet, restored water, and tested for proper operation. Faucet now shuts off correctly with no leaks and normal water flow. Customer advised on routine maintenance and signs of future cartridge wear.