Cancel and slide bar not working

After repairing my digitizer screen and wifi antenna, the cancel button and slide bar do not work. The slide will not slide. The red power slider works. I have tried everything I can find on you tube, google, etc. In removal of screen to replace wifi antenna, a small piece of black foiled lined tape(?) tore away. Searched the Internet hoping to locate what that tape is and try to repair it. No luck. Can anyone offer help, other than the trash an? I have already purchased a new iPad mini, but hate that a $800.00+ gadget is just staring at me from the table.