In fact, it wasn't as clear-cut as that. The only assurances it had given Apple were that it wouldn't sell them before April 30, a date it then pushed back to May 30, according to Hong Kong court documents. These also showed Proview Shenzhen was quietly trying to transfer the trademarks to a subsidiary, Yoke Technology.
But time was running out. Legal proceedings by Chinese creditors to recover assets prompted the Hong Kong Stock Exchange to suspend trading in Proview shares on May 12.
Two days later, a Chinese court ordered Proview to sell off assets of another Chinese subsidiary, Ningbo Prowell. On May 20, Apple began legal action against Proview in Shenzhen.
The battle to save Proview International was lost.
By mid 2010, Yang had been forced to publicly concede that the bankruptcy proceedings against him were related to him loaning money to Proview; on August 2, he lost the case and resigned from the board of Proview, whose shares were suspended.
The company was effectively moribund: some HK$3.83 billion (S$622 million) was overdue, while loans guaranteed by Yang himself amounted to HK$1.15 billion, according to company filings.
At its peak, Proview had employed 18,000 people and had offices across the world. Now, only a few hundred staff remained, mostly at the company's Wuhan plant. Its Hong Kong headquarters is empty and its phone numbers no longer work. Only the factory in Wuhan continues to function. The plant in Shenzhen is a ghost town.
All activity centres on the trademark case.
Yang is quick to blame the financial crisis for his company's downfall; many of his clients in the United States went bust, he said, or were in dire financial straits. He points to Circuit City, which filed for bankruptcy in November 2008. But analysts note many other companies rode the crisis.
Yang remains optimistic he can both win the case against Apple and rebuild his empire. But there are plenty of obstacles.
First, there's his role: although still, through his son, the controlling shareholder of the group, Yang is a bankrupt in Hong Kong. A Hong Kong court has been critical of his role in the trademark dispute, saying he was an active participant in what the judge called a "conspiracy."
Yang says that position as chairman of Proview Shenzhen is simply because "creditors in China didn't want to deal with another person who is not familiar with the company."
Beyond that, the relationship with Tatung, still a significant shareholder, seems to be on ice. Both Tatung directors resigned in 2011. Yang has engineered the removal of his successor, Elina Hui, as chairman because, he says, "she did many things against the company's principles."
Proview has filed a lawsuit against her. It was not possible to reach Hui for comment. The company, which has yet to file annual reports for 2010 and 2011, faces de-listing in June if it cannot submit viable proposals for resuming business.
Yang is undeterred, and convinced he can still take on his competitors. But he does acknowledge he would do it differently now. "Now that I think of it," he says, "it was a mistake to just blindly focus on expanding. I should have gone after profitability instead."
"I hope we can return to our glory days. I'm sure our shareholders are hoping for the same."