Are you sure nothing is wrong with the charger? I suggest try that charger in another device and another charger on yours to see if anything changes.
Also, you may want to try charging your laptop with your battery when it is off (not hibernate or sleep but off) to see if it will charge then. If it will charge when turned off, but not when on, then the charger does need to be replaced. That is a common sign of them not putting out enough power to both run the device and charge the battery. So it is best to test to be sure.
If you test all that and it still doesn't get you an answer, then the charging circuit on the motherboard may be gone/dead and could mean the motherboard would need replacing.