https://motherboard.vice.com/en_us/article/ne9qdq/warranty-void-if-removed-stickers-illegal-ftc

As we’ve reported before, it is bullshit and illegal under federal law for electronics manufacturers to put “Warranty Void if Removed” stickers on their gadgets, and it’s also illegal for companies to void your warranty if you fix your device yourself or via a third party.

The Federal Trade Commission put six companies on notice today, telling them in a warning letter that their warranty practices violate federal law. If you buy a car with a warranty, take it a repair shop to fix it, then have to return the car to the manufacturer, the car company isn’t legally allowed to deny the return because you took your car to another shop. The same is true of any consumer device that costs more than $15, though many manufacturers want you to think otherwise.