Why won't my buttons work for TI 84 Plus CE

There's an issue with two keys, the log key and the 7 number key, for some reason whenever I click it there is no response, I tried redownloading the os but it won't work, as per damage the entire case is fine, no scratches or dents and no water damage other than normal humidity, I am not sure if it is a stuck key I don't know what that is. I tried opening it up once but they heat up the plastic in there so it stays in place and you can't take it apart. Regardless this issue pursues no matter what I do, and I am unable to purchase another one due to financial stipulations. Any ideas