Power on issues Dell 5150

Hello,
I have a Dell 5150 lap and the customer brought it in saying there was no sound. As we were installing the drivers, the battery died. Then we noticed the lap ONLY running off of the battery and NOT the power cord. I remember the customer saying something about "If you wiggle the cord, when you get the "This is the wrong power cord and it will operate at decreased efficiancy" error message", the box will go away. Yeah, the error goes away however when the charging status is checked, it says the battery will not charge....Ok, so we replaced 3 power receptacles and get the same issue. Wont power off of the cord but WILL off of the battery. Of course we tried 3 different RIGHT power cords. We're stumped. The power cord gets a signal TO the MoBo and the operating system but will NOT charge the battery. The lap WILL power and boot off of the battery with no issues. Is this board just toast or is there an issue that someone knows about?
Thanx for any support, Steve