Chosen Solution
one day, my ethernet port suddenly stopped working. I ran a hardware test, and it failed. How do I fix that?
You’ll need to pop the bottom cover off and inspect the logic board for damage. flow this iFixit guide MacBook Pro 13" Unibody Mid 2009 Logic Board Replacement Most likely you have a bad Ethernet Modem or transformer. The easiest way would be to replace the logic board.
