Demand in China has begun surging for a business that, in theory, shouldn't exist: the repair of advanced Nvidia artificial intelligence chipsets that the U.S. has banned the export of to its trade and tech rival.

Nvidia's most powerful chips are banned for sale to China.At least $1 billion in Nvidia computer chips were smuggled into China in the three-months span after President Trump imposed

At least $1 billion worth of Nvidia’s advanced artificial intelligence processors were shipped to China in the three months after Donald Trump tightened chip export controls, exposing the limits of Washington’s efforts to restrain Beijing’s high-tech ambitions.