Only the button designated for child lock or control lock will work. Have you tried pulling the plug and removing the top cover and unplugging for a couple of hours? While you are waiting check the panel by removing, has soft clips and maybe a couple screws and then pull gently from the top and then the bottom. The board is clipped in and may be loose. If not replace. On the newer machines the button is lower left and hold for 3 full seconds.