AC adapter is not able to charge the laptop!

Hello,
I got a problem in adapter & got it repaired, but the idot reversed the connection i.e. +ve & -ve supplies. I was not aware until I failed to switch on my laptop. Later I tried with new adapter, but the problem is now that even with this I am not able to charge the laptop. Its running fine on battery & showing no problem. I doubt the power ckt on mother board ( or some chip board ) is damaged. Plz provide some help.