CFO Yoshida takes over Sony as CEO: Is the fun over at the Japanese giant?

When it comes to crunching numbers or winding down bad businesses, nobody at Sony Corp has been as sharp as Kenichiro Yoshida. Now, as chief executive officer, he faces a tougher task: rekindling some lost magic.

The driving force behind Sony’s turnaround during the last five years when he was in charge of finance, the reserved 58-year-old took the company’s top job yesterday. Investors love him, but managers who worked with him said they worry he isn’t in love with the kind of gadgets that once made Sony a household name.

Sony is making record profits again, but it’s no longer making the world’s coolest stuff. The company that gave us the Walkman and the Trinitron color TV has become a less-inspiring hodgepodge that includes an insurance provider and a semiconductor maker, along with Playstation game consoles and movies. Once ranked the No.1 brand by American consumers, Sony and it’s incoming CEO need new hits to keep from falling further behind Apple Inc. and Samsung Electronics Co.