My battery is not in charge, magsafe always green

Hi everyone,

I have a problem with my macbook pro mid. 2009 from a year. My battery is not in charge and the magsafe is always green. I tried to change my battery and the charge, for 3 months it was ok, but then suddenly it returned as before. I really don't know what it could be the problem.

I tried with a friend MBP: my magsafe works normally in his MBP, become orange and charge correctly.

His magsafe doesn't work normally in my MBP, it remains green.

I tried to switch our battery and with his battery and magsafe in my MBP it doesn't work.

My battery works in his computer. So magsafe is ok, battery is ok.

Is the DC-IN board to replace or logic board? Have any ideas?

Thanks

Marco