There has to be a fascinating back story to the Best Buy soap opera. In the latest twist, Best Buy says that company founder Richard Schulze told directors this morning that he would “resign from the board, including the chairmanship, effective immediately.” The head of the board’s Audit Committee, Hatim Tyabji, was named the new chairman. Schultze said in a separate statement that he made his decision “in order to explore all available options for my ownership stake.” He’s by far the largest shareholder, with 20.1% of Best Buy’s shares. The announcement upends a face-saving arrangement reached last month after the Audit Committee said in a report that Schulze helped to cover up former CEO Brian Dunn’s “inappropriate relationship” with a female employee. The multi-billionaire agreed to remain on the board as chairman until the June 21 annual meeting when Tyabji would take the gavel. Schulze then would stay to the end of his term next year with an honorary title of Founder and Chairman Emeritus. It was a humiliating come-down for the man who turned his Sound Of Music Store founded in St. Paul in 1966 into one of the country’s largest sellers of consumer electronics and entertainment. The company’s statement this morning calls Schulze “an iconic entrepreneur” who “changed the landscape of American retail.” He was forced aside, though, after Best Buy’s board reported that Schulze found out about Dunn’s relationship in late 2011 but kept it to himself after the ex-CEO “adamantly denied” any impropriety. The board first learned of the relationship in March. The contretemps took place as Best Buy struggles to keep up with competition from online retailers led by Amazon. Best Buy shares are down 7.2% in early trading today — and -35.7% over the last 12 months.