Cal. Health & Safety Code § 40820

Except as provided in Section 40501.1, subdivision (c) of Section 40824, subdivision (c) of Section 40825, Section 42351.5, and Section 42359.5, three members of the hearing board shall constitute a quorum, and no action shall be taken by the hearing board except in the presence of a quorum and upon the affirmative vote of a majority of the members of the hearing board.