why won't my inspiron 1525 recognize my a/c adapter?

my dell inspiron 1525's screen is extremely dark and won't recognize my a/c adapter, though it will turn on while it's plugged in. I bought a new inverter so i'm pretty sure that''s not the problem, and my a/c adapter is relatively new as well. I jerked the a/c adapter around a bit and it didn't do anything, so i'm pretty sure it's not the dc socket. does anyone have any ideas?