Chosen Solution
I only lost the use of 3 keys. They are under each other so somehow they are connected. I am wondering if it’s repairable. Right now I have attached another keyboard by USB connection. It’s a hassle but it works.
keyboards are single units. you would need to replace the board if worse comes to worse. However opening it up, and using an Isopropyl 99% alcohal and a toothbrush, id suggest scrubbing at both the connectors for the board, and at the indevidual key sections. may clear out the mineral corrosion, and fix it.
Here’s the guide for replacing a keyboard that should work for your model: MacBook Pro 13" Unibody Mid 2010 Keyboard Replacement
