Amazon or a trusted eBay seller will probably have it for you. If you're looking at buying it online, make sure it's a reputable seller and you're getting what you're paying for. Also check up on the model number as that's a good way of telling whether you're getting the right one or not, as I'm sure there are many Chinese models posing to be the correct model when they are actually generic incompatible power supplies that aren't the genuine product. If online isn't your thing, check a local tech store, I'm not sure how it works where you live but in my city, we have a gaming store that supplies all these parts, it's just that they are more expensive than online.