AC adapter or commonly called laptop charger is used to provide sufficient power for operating the laptop for extended period and recharge the battery on a laptop PC. When the AC adapter (charger) fails to work, it will neither charge the laptop battery nor provide power to operate the laptop PC without battery power. Power issues on laptop PCs are compounded because a laptop has two power sources: AC adapter (charger) & battery. When AC power is not available, power is provided by the laptop battery.

Following are the common adapter failure symptoms: 

AC adapter is not able to charge the battery.

AC adapter is not able to power on the laptop PC, the lights or LEDs do not illuminate. 

AC adapter LED is off.

The AC adapter type cannot be determined. This will prevent optimal system performance.