The rubber button mechanism might be worn out. Here's a [https://www.google.com/aclk?sa=L&ai=Cw-6LnttuVue_Kcu2hASX8qWgA4n1u7AH2bbRvMcB6ZXVjs8DCAYQAygEYMnexIvEpJAQyAEHqgQnT9Ab0N95x8labIxaEBZHLQR9V7X7cqYCyDKzSVIJsOAGnAhdsuhqwAUFoAYmgAfbgI4ViAcBkAcCqAemvhvYBwHgEq708qvWvqDRtwE&sig=AOD64_0CunygAvmlhFq8o8Grb-CL-XScqQ&ctype=5&q=&ved=0ahUKEwi984P10NvJAhXLQyYKHdXkDUQQuxcIfQ&adurl=http://rover.ebay.com/rover/1/711-117182-37290-0/2%3Fmtid%3D1588%26kwid%3D1%26crlp%3D53601919689_324272%26itemid%3D221814543888%26targetid%3D124316371689%26rpc%3D0.14%26rpc_upld_id%3D60210%26rlsatarget%3Dpla-124316371689%26device%3Dc%26mpre%3Dhttp%253A%252F%252Fwww.ebay.com%252Fulk%252Fitm%252Flike%252F221814543888%253Flpid%253D82%2526chn%253Dps%26adtype%3Dpla%26loc%3D1023626%26poi%3D9015716%26campaignid%3D239125209%26adgroupid%3D14978428809|link] to a set of replacements. Follow the [guide|12873|analogue stick replacement guide] to get to them. Good luck!