When you say it won't charge, does it charge at all?
1. It indicates that it is charging, but as soon as you unplug the charger the battery quickly or immediately indicates it is dead. If the laptop is off, the LED on the laptop shows it is charging but the battery is always dead,
Or: 2. It is as if you didn't have the charger plugged in. No light on the laptop at all when the charger is plugged in.
1. The battery has died and is no longer capable of taking a charge. An alternate explanation if you can't even get the laptop to turn on even though the laptop charge LED is on, is that the internal power supply that converts the incoming and battery voltage to all the voltages required has died.
Or: 2. The power connector inside the laptop is a common failure point. The solder joints break from various minor shocks over time. This is going to become more common with lead-free solder as it is more brittle. Less likely is that the charging circuit inside the laptop has failed.http://www.chargerbuy.com/laptop-ac-adapter/universal-ac-adapters.html