Chosen Solution
Having a problem with this machine. It sometimes starts charging up but most of the times not. Most if the times laptop doesn’t even detect the charger . otherwise laptop is working fine no other problem. i opened up the laptop, removed the logic board and saw a very liitle liquid damage near where charging socket connect with logic board. After cleaning it not charging up now means no light in charger . i already changed the charging connecter also.
Change the AC adapter and let us know what you get.
I had a similar problem with a water damaged 15" mid 2009 Unibody Pro. It would not charge, not recognize the connected power adapter everytime, and would sometimes display a dim green light. I changed the battery and it still did not remedy the problem I eventually disconnected the led battery life indicator ribbon from the logic board and it started charging immediately!! Once I removed the led indicator, it was obvious that it had shorted out due to water damage. So before trying a new logic board, I would definitely try this!!