HP guarantees that the HP Hardware Products that you have purchased or leased from HP are free from defects in materials or workmanship under normal use during the Limited Warranty Period. The Limited Warranty Period starts on the date of purchase or lease from HP. Your dated sales or delivery receipt, showing the date of purchase or lease of the product, is your proof of the purchase or lease date. You may be required to provide proof of purchase or lease as a condition of receiving warranty service. You are entitled to hardware warranty service according to the terms and conditions of this document if a repair to your HP Hardware Product is required within the Limited Warranty Period.http://h40059.www4.hp.com/warranty/support/tc.php
And if you can not provide proof that HP needs or have some trouble getting a replacement adapter directly from HP, there is another site you can try: www.chargerbuy.com
, they provide adapters for almost all HP models.