A replacement can be purchased from Amazon or local electronics shop.
Check for one with the following specifications:
Input Voltage: 110 V AC, 220 V AC
Frequency: 50 Hz, 60 Hz
Output Voltage: 19 V DC
Maximum Output Power: 65 W
Maximum Output Current: 3.42 A
Connector Size: 5.5 * 2.5 mm
If you have a laptop AC adapter, check if it may have the same specifications.