He has no inherent power. It's that simple. His recommendations are not binding. He can request information and the University may order it to be produced. He has no legal mechanism to compel truthful testimony, to sanction witnesses, or to compel production.
Here's the disturbing thing. Did you realize that Penn State University is not subject to the Pennsylvania Open Records law?
When Penn State gave up its private status in the early 1970s it did not become a member of public Pennsylvania State System of Higher Education. Instead, it's a member of Pennsylvania's Commonwealth System of Higher Education, like Temple and University of Pittsburgh. Universities in the Commonwealth System of Higher Education are considered 'public' universities and receive public money, but they are under their own independent control rather than control of the Commonwealth of Pennsylvania. Penn State controls Penn State; the Commonwealth of Pennsylvania does not. And the state open records laws do not apply to Penn State.
I continue to find the ex officio role of the Governor, Tom Corbett, on the Board of Trustees fascinating. Did you realize that in 2009, Corbett, as State Attorney General, began the Sandusky investigation? It was only after he was elected governor in 2010 that he ceased to be involved in the Sandusky investigation. And he sat on the Board of Trustees (unable to disclose things he knew through the grand jury and other investigative processes) with fellow Board members. No wonder the Penn State Trustees acted so quickly to fire Spanier and Paterno once Governor Corbett arrived for the Board's special meeting.
I was not aware of any of this additional information. Quite fascinating.