Chosen Solution

Keyboard and keypad doesn’t work on my MacBook Air except the power on an off Could it be the ribbon? This is the ribbon on the end that looks like corrosion The ribbon

Yes, it does look like corrosion damage. While the cable should be replaced, I fear your trackpad likely needs replacement too! MacBook Air 11" (Mid 2013-Early 2015) Trackpad CableMacBook Air 11" (Mid 2013-Early 2015) Trackpad Here’s the guide MacBook Air 11" Early 2015 Trackpad Replacement