Former "Family Ties" actor Brian Bonsall has been charged with second-degree assault after police say he repeatedly hit a friend in the head with a broken wooden stool.Bonsall could face between two and six years in prison if convicted of the charge that prosecutors filed Friday.Bonsall, 28, was arrested Saturday and appeared briefly in a Boulder courtroom Wednesday morning. Police said he was involved in a fight at an apartment in the 1100 block of 11th Street in Boulder on Saturday. The victim told police that Bonsall hit him with a part of a broken wooden stool.Bonsall allegedly told officers he had been drinking that night and didn't remember what had happened but identified the man who called police as his "best friend." Police had been called to the residence three times before they arrested Bonsall. Police say Bonsall was also wanted on a warrant for missing a court hearing in 2007 on suspicion of violating bond conditions on another case. In that case, he had been sentenced to two years of probation for his girlfriend's assault. Bonsall played the role of the youngest Keaton sibling, Andy, on the NBC sitcom starring Michael J. Fox.He lived in Boulder for several years and graduated from Boulder High in 2000. He had several run-ins with authorities after that, including a 2004 arrest for drunken driving and an arrest in 2007 for assaulting his girlfriend.