Can some one please help me , i have a vetch toy aeroplane and one fisher price small musical robot , when i put the new batteries, they only do a buzz sound and stop working, i takeout the batteries and put it again they only do a buzz of music fr a second and stops again, i dont want to throw it and my little girl really want that mummy fix it. there is no corrosion in the battery compartment, its all clean. please help me