Xbox One Power Supply Units Now Available to Buy
You can get a new one for as little as $35 if it's not covered under your warranty.
Up until recently, there was no way to buy an additional Xbox One power supply, which was kind of a bummer if you needed one. But now, Microsoft has added that very option to the Xbox Support site.
Simply head to the Xbox Support site, select "Replace an Accessory," and then choose Power Supply. From there, you can either choose to return a non-functioning power supply to Microsoft and get a new one for $35, or you can buy a new one outright for $50.