United States Federal Law (15 U.S.C. § 2301), defines what the standards for US warranties are and the circumstances which a manufacturer does not have to honor a warranty.
It is illegal for a company to void a warranty, as there is no provision in the US standards for warranties that allows it. Companies can only deny warranty claims on a case by case basis. There is no such thing as voiding an entire warranty, period. If a company violates these provisions consumers have a right to recover reasonable costs in getting the company to follow the law, including time effort, lost wages and legal fees.
It makes absolutely no sense to void an entire warranty if there is evidence of liquid damage. Just because there has been evidence of liquid damage does not mean that every single component of a product is completely broken and will never work again. That would be an unreasonable conclusion. For example if you pour liquid onto your keyboard, and the keyboard dries out and everything works fine, and then your webcam at the top of your screen that never contacted water stops working because it was assembled improperly and the focusing gear gets stuck, it would be ridiculous to conclude that your webcam should not be replaced due to an unrelated even that was completely isolated on an entirely different part of the device.
Unfortunately too many people do not understand the law when it comes to these situations.