The 13" MacBook Pro was my son's computer. A Genius at an Apple Store diagnosed the problem but my son is a grad student and needed a computer so he bought an Air and gave me the old one. This is the second MacBook of his that I repaired and kept.
The unibodies are a piece of cake, unlike some of the older ones.
After retirement, I worked at a school district doing tech support. After I discovered iFixit, my job was much easier.