MacBook Pro mid 2010 sometimes take charge and somtimes not

Hi!

I have a macbook pro (mid 2010) that has a strange problem. Everything works well except the charging part. Often when i plugg in my charger, nothing happens. The macbook won't recognise that the charger is in fact attached and the green/orange light on the connector won't light up. If i unplugg the charger and wait a little while and then replugg the charger, it works and the macbook is charging normally

I bought the macbook from a friend that told me that he believes it is a fault on the logicboard. Can this be the problem? Is it possible that something is wrong with the DC-in board?

So to clarify, the macbook sometimes recognise the charger and sometimes it won't. Everything else works like a charm and the computer runs perfectly on battery.

Best regards

Olof from Sweden